JPS6083699A - Control of recirculation type 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 (a) Industrial Application Field The present invention is directed to a circulating air path in which exhaust air from a drying chamber is cooled with a dehumidifier to remove moisture, then reheated with a heater and supplied to the drying chamber. The present invention relates to a circulating clothes dryer having:

(b) Conventional technology In most conventional dryers, the operating time was determined by the user using a timer based on the type, amount, moisture content, etc. of the clothes. It often took a long time to dry, or the drying process was insufficient and the drying process had to be repeated.

Therefore, by taking advantage of the fact that the temperature of the exhaust air from the drying room rises rapidly when the degree of dryness reaches about 80%, the temperature difference between the outside air temperature and the exhaust temperature is detected, and this temperature difference becomes an almost constant value. 2- is stored as a reference value, and the drying is terminated when the difference between the outside air temperature and the exhaust temperature becomes larger than a predetermined constant value from this stored value. This is considered in Publication No. 1982-19296.

However, this device detects the outside air temperature as a temperature to compare with the exhaust temperature, and this outside air temperature becomes unstable when the dryer is used indoors (in this case, the outside air temperature becomes the indoor temperature). Also, if the air volume changes due to filter clogging or the power supply voltage changes, the exhaust temperature will change and the outside temperature will not respond to these changes, so it is difficult to always perform accurate control. However, there was a risk that the drying process would be too dry or end up being left undried.

Furthermore, if there is a large amount of clothes to be dried, the difference between the exhaust temperature and the outside air temperature will rise once and become almost constant, but then the difference will rise slightly, and drying will continue based on the initially memorized reference value. However, if the amount of clothing is controlled, there is a problem that drying may not be sufficient even if the amount of clothing is not large.

<C> Purpose of the Invention 3. The purpose of the present invention is to provide a circulating clothes dryer, which is capable of detecting a certain degree of dryness and ending drying without being affected by external factors such as outside air temperature; The object of the present invention is to provide a control method that can obtain a desired drying rate even when drying a large amount of clothes.

(D) Structure of the Invention The present invention provides that in a circulating clothes dryer, the temperature after passing through the dehumidifier in the circulation air path and the temperature after passing through the dehumidifier in the cooling air path do not change stably during drying. Focusing on the fact that the temperature of the exhaust air from the drying chamber changes depending on the temperature, the first heat-sensitive method measures the temperature of the air that passes through the dust remover in the circulation air path, that is, the temperature of the exhaust gas from the drying chamber. and a second heat-sensitive element that measures the temperature of the air after passing through the dehumidifier in the circulating air path or the temperature of the air after passing through the dehumidifier in the cooling air path that cools the dehumidifier by applying outside air to the dehumidifier. and storing the temperature difference as a reference value when the difference in temperature measured by the flesh-sensitive thermal element reaches a substantially constant value after a predetermined period of time has elapsed from the start of operation;
The drying operation is terminated when the measured temperature difference reaches a predetermined value or more within a predetermined period of time from the memorized reference value, or after a predetermined period of time has elapsed. If the measured temperature difference does not reach the predetermined value or more, the predetermined value is gradually increased over time 15.

(e) Examples Examples of the present invention will be explained based on the drawings. (1) is an outer box, the rear opening of the sheep is covered with a back plate (2:), and the front side of the box is provided with a clothes slot (4) which is opened and closed by a door (3). (6) is a drum serving as a drying chamber in which clothes are placed, and the front end of its peripheral wall (7) is fitted with a front rasp 9 (12') through a sliding member such as felt (13). . At the center of the rear wall (8) of the drum (6) is a shaft
4) is provided protrudingly, and this shaft body (14) is inserted through a cylinder (16) ^1 metal (17) formed in the center of the support plate (15), and the tip 1 of the shaft body (14) This washer (
18) Through the tapping screw (1!l))
5. Make sure that the shaft body (□14) does not fall out from the tube (16).
There are 75 people here. As shown in Figure (2), the support plate (15) has flanges (20) (2) formed at both ends at the rear ends of the upper and lower surfaces of the outer box (1).
1) is fixed. □ A plurality of air discharge holes (22) are provided in the rear wall (8) of the drano (6), and a rear duct (23) that passes through the inside of the drum (6) and the seedlings via the rice discharge holes (22). is solidly attached to the support plate (15). The discharge hole (22) is
A removable filter cover with a letter mesh (24) (
25). (26) is the rear duct (23)
This is a thin member that prevents air leakage between the rear wall ('8) of the drum (6) and the rear wall ('8) of the drum (6). □ The outlet (33) of the rear duct (23) is connected to the suction duct (36) of the circulation fan tarsing (35) via a connecting pipe (34'). This fan casing (37) has a small pulley (
39) is connected to the shaft (4) of the motor <41> by the belt (40).
The motor (41) is rotated by being connected to the dog pulley (43) fixed to the shaft (42).A small pulley (44) is also fixed to the shaft (42>) of the motor (41), and this small pulley - By winding the heald (45) between the outer periphery of the drum (6) and the drum (6),
) is also rotated at low speed. In Figure 2) (46) is an idler pulley that adjusts the tension of the belt (45).

Discharge duct 1-(47) of circulation fan casing <35)
is communicated with one end side of the large number of pipes (49) of the dehumidifier (48>.
> and a number of cooling fins (50) perpendicular to this pipe.
It becomes more. In Figure (3), (51) is a cooling fan,
A suction duct (53) of the cooling fan casing (52) is connected to an outside air intake (54) opened on the top surface of the outer box (1), and a discharge duct 1-(55) is provided inside the cooling fan casing (52). ) is connected to the upper end surface of the cooling fin (50>).The cooling fan (51) is fixed to the shaft (38) of the circulation fan (37).The cooling fan (51) As shown by the dotted line arrow in Figure (3), the rotation of the outside air sucks outside air from the outside air intake port (54) through the filter (61) and sends it to the cooling fins (50), and the damp air passing through the inside of the pipe (49) is A cooling air path is formed by cooling the warm air, condensing the moisture contained in it, and exiting it through a number of exhaust holes (56) provided at the bottom of the outer box (1).A number of pipes. (49> On the other end side, there is a front duct h
(57) is connected to one end, and the condensed water is drained to the drain hose (58) connected to the lower surface of this front duct (57).
More water is discharged outside the aircraft.

The other end of the front duct I-(57) is connected to the drum support plate (1).
1), and the drum support board (11) is provided with a large number of air intake holes (59) that communicate the inside of the front duct (57) and the inside of the drum (6). A heater (60) is also installed inside the duct (57).

Then, when the heater (60) is energized and the motor (41) is rotated, the circulation fan (37), the cooling fan (51), and the drum (6) rotate.
4> Drum (6) from the intake hole <59) as shown by the solid arrow in the figure.
The air heated by the heater (60) is completely supplied to the inner drum, evaporates moisture from the clothes in the drum, and this hot and humid air flows through the filter cover (25) and the discharge hole (22) to the rear duct (23). ) into the rear duct (2
3> is sent through the connecting pipe (34>) to multiple pipes (49) of the dehumidifier 8- (48), where it is cooled as described above and the moisture contained therein is condensed. The air is sent through the front duct (57) to the heater <60), heated again, and then supplied to the drum <6) through the intake hole (59), repeating the cycle. Solid arrows represent circulation air paths.

In the discharge duct (47) of the circulation fan casing (35), there is a first heat-sensitive element (61) for measuring the temperature of the air before passing through the dehumidifier in the circulation air path, that is, the drum outlet temperature. is provided. Here, the heat-sensitive element (61)
A thermistor is used as a

Further, below the dehumidifier (48) in the cooling air path, a second heat-sensitive element (62), also made of a thermistor, is provided to measure the temperature of the air after passing through the dehumidifier, that is, the temperature at the outlet of the dehumidifier. .

Next, the control circuit will be explained based on Fig. (5). (63
) is the power on switch, (64) is the first door switch,
(41) is the motor, and (60) is the heater.

(65) is a DC converting circuit, in which the DC voltage rectified by this circuit is converted into a plow-wave pulse by a waveform shaping circuit (66), and then this pulse is applied to a microcomputer (67) for a time period of 1. -Used for. (68) is a clock oscillation circuit that generates pulses used to advance the program in the microcomputer (67). (6
9) is an initial reset circuit, which operates when the power supply switch (63) is pressed to set the program in the microcomputer (67) to its initial state. (61) is the thermistor that is the first heat-sensitive element, and (62) is the thermistor that is the second heat-sensitive element. Each thermistor is connected in series with the resistors (70) and (71), respectively, and their respective partial voltage values are compared with each other. vessel (72) (7
3) is entered. Also, each voltage comparator <72> (73)
The other input terminal of the microcomputer (67)
A ladder circuit (74) that generates a staircase wave by receiving the output from
) is being input. This ladder circuit is connected to the output terminals (A) and (A) of the microcomputer (67).
... (g), and as signals are output from each output terminal in sequence, the output voltage of the ladder circuit (74) changes in a stepwise manner, and the voltage comparators (72) and (73) become conductive. When there is an input to the microcomputer 10- (67), the microcomputer itself determines which of the output terminals (A), (B), ... (G) the signal was output from. The drum outlet temperature of the circulation air path and the dehumidifier outlet temperature of the cooling air path are determined by the judgment. (77) is a second door switch for determining whether the clothes loading door is closed;
78) is a 50/60Hz changeover switch, and (75) is a start switch for starting the drying operation. (79
) is the first relay winding, and the start switch <75)
When pressed, the output signal from the microcomputer <67> causes current to flow through the transistor to this first relay winding (79), and the first relay contact (79')
is closed to energize the motor (41). Further, (80) is a second relay winding, (81) is a light emitting diode for displaying drying operation, and when the drying process has progressed, the light emitting diode (81) is energized via a transistor by a signal output from the microcomputer (67). At the same time, the second relay winding (80) is energized and the second relay contact (80) is turned on to indicate that the drying process is in progress.
') is closed, and the heater (60> is energized through the first door switch (64), etc.) (84) is a buzzer for bales at the end of operation, and (85) is a light emitting diode that lights up to indicate cold air operation. (86) is a power plug.

The operation of the above configuration will be explained below. When the power supply switch (63) is pressed, DC voltage is applied to the microcomputer (67) through the DC conversion circuit (65), and the initial clear circuit (69) is activated to transfer the program in the microcomputer to the thermistor, which is the initial element. (62>, ladder circuit (74) and voltage comparator (72)
(73) sets the drum outlet temperature and dehumidifier outlet temperature to 1.
Measurements are made at intervals of seconds, and the values are stored in a microcomputer
) is stored in RAM (read/write memory). Press the start switch (75), and if the clothes loading door (3) is closed, press the first and second door switches (64) (7).
7) is closed, and the microcomputer (67) detects that the 21st switch (77) is closed, outputs an output current to the first relay winding (79), and connects the first relay contact (79'). is closed and the motor (41) is energized to rotate the drum (6) and both front fans (37) and (51), and at the same time output current is also output to the second relay winding (80) to connect the second relay contact. (80') is closed and electricity is supplied to the -tater (60) to start drying operation. Also, a microcomputer (
67) counts the number of pulses of the power AC wave converted into a rectangular wave by the waveform shaping circuit (66) to count the operating time.

This counting is performed by using a specific address in the RAM as a time counter, and the time that is counted and stored here is updated every 1 minute.

By the way, the difference between the drum outlet temperature and the dehumidifier outlet temperature measured by the first and second heat sensitive elements (61>(62)) changes approximately as shown in FIG. (6) during the drying operation.

That is, after the start of drying, the difference between the two temperatures increases for a while, but when a certain temperature difference (A) is reached, the continuous condition hardly changes to a steady state. This steady state
``1'', ``1°゛1 after 1 above 2-') (7) Temperature difference-
13= begins to increase, but the drying rate at this time is approximately 80%. Therefore, in Figure (6), the above two temperature differences are (A+
B) degrees (where B is a predetermined arbitrary regular number of months) If the drying operation is stopped, the operation can be completed with a drying rate of about 90%.

Note that the time required for the above two temperature differences to become approximately constant (T
In 1), the longest time in the experiment under various loads is defined as the time (T1), which varies somewhat depending on the load amount and dehydration rate, and the temperature difference between the two above at that time is the temperature difference (A). And it is sufficient. However, since the steady state is quite long, the time (T1) may be set to be long with some margin.

Therefore, when time (T1) has elapsed after the start of operation, the drano outlet temperature and the dehumidifier outlet temperature that had been constantly updated and stored in the RAM are taken out and the difference between them is calculated.
Using that value as the reference value (,A), when the temperature reaches R(A+B) degrees, the drying operation is finished and the cold air operation is started (-t4-4゛ when the heater (60) is turned off and only the air is applied to the clothes). Transition.

The above is a case where the load amount is less than the rated capacity, and in this case, the desired drying rate can be reached and drying can be completed by the time t1 elapses from the start of operation.

However, if the load amount is larger than the rated capacity, the difference between the two measured temperatures does not reach (A+B) degrees within the time and tl, and the operation cannot be completed. This is because, as can be seen from the two measured temperature differences in the case of a large load shown in FIG. 7, drying takes a long time and the steady state of the temperature difference becomes long. Also, during this steady state, the drum outlet temperature increases slightly and the difference between the two measured temperatures also increases slightly, becoming (A+C) degrees greater than the initial temperature difference A. So, assuming the reference value is A, the measured temperature difference is (A + B)
If you end the operation when the temperature reaches 30 degrees, the drying will not be sufficient, and if the reference value is set to (A + C) degrees, the measured temperature difference will be (A + C).
If the operation is stopped when the temperature reaches C+B), sufficient dryness can be obtained even when the load is heavy.

In the present invention, the amount of change C in the temperature difference in a steady state is corrected, and if the temperature difference does not reach (A+B) degrees even after the time t1 has elapsed since the start of operation, a predetermined value is added to the reference value A. Increase the value of B and set the value as bl. If the temperature difference reaches (A + bl) degrees by the time the time t2 (t2>tl) has elapsed, the drying operation is stopped and the cold air operation is started.
If bl) degree is not reached, bl is corrected and b2(b2>
bl), and when the temperature difference reaches (A+b2) degrees, drying is stopped and cold air operation is started. In this way, by gradually increasing the predetermined value B added to the reference value A according to the drying time, sufficient drying can be achieved without insufficient drying even when the load is large. In the flowchart of FIG. (8), 'ACCJ' is an accumulator.

Figure (9) is a flowchart showing another embodiment. In this case, the reference value A is set when 15 minutes have elapsed since the start of operation, that is, when T1=15 minutes, and when the reference value A is set. The predetermined value B to be added was set to 5 degrees. And 30 minutes after the start of operation
If the measured temperature difference reaches (A + 5) degrees within 30 minutes, the drying operation will be stopped and the cold air operation will begin.
5. When the temperature does not reach 5 degrees, the predetermined value B to be added to the reference value is increased according to the operating time.

In other words, when the time it takes for the temperature difference to reach (A+5> degrees) is from 30 minutes to less than 60 minutes, the value of B is increased by 2 degrees from the original value, and when it is from 60 minutes to less than 90 minutes, the value of B is increased from the original value. The value of B is increased by 4 degrees from the original value, and when the time is from 90 minutes to less than 120 minutes, the value of B is increased by 6 degrees from the original value.
If the temperature difference still does not reach (A+5) degrees even after minutes have passed, the system shifts to cold air operation. This is the thermistor (6
1) This is protection when (62) etc. are out of order.

After the drying operation is completed and the cold air operation is started, the process ends.

In the embodiment shown in FIG. 8, when the temperature difference between the drum outlet temperature and the dehumidifier outlet temperature reaches (A+B(bl, b2)) degrees, the drying operation is stopped and the cold air operation is started. However, the above temperature difference is (A + B (bt, b
2)) After the drying rate is reached, the drying operation may be continued for a period of time set separately using a drying rate adjustment timer.

In addition, in the above embodiment, the difference between the temperature before entering the dehumidifier in the circulation air path, that is, the temperature at the drum outlet, and the temperature after passing through the dehumidifier in the cooling air path was measured. Instead of measuring the temperature after passing through the dehumidifier, a second heat sensitive element (62) may be provided at the position indicated by the dashed line in FIG. 3 to measure the temperature after passing through the dehumidifier in the circulating air path.

That is, the temperature difference before and after the dehumidifier in the circulating air path may be measured.

This is because the temperature difference here and the temperature difference explained earlier show similar changes. However, the temperature difference before and after the dehumidifier in the circulating air path is smaller than the temperature difference described above.

(F) Effects of the Invention According to the present invention, the temperature before passing through the dehumidifier in the circulating air path, the temperature after passing through the dehumidifier in the cooling air path, or the temperature after passing through the dehumidifier in the circulating air path. Since the drying time is controlled by measuring the difference between 18 and 18, it is possible to accurately control the ratio by measuring the difference between the temperature of the exhaust air from the drum and the temperature of the outside air. Firstly, the outside temperature tends to become unstable when the dryer is used indoors, whereas the temperature after passing through the dehumidifier in the circulation air path or cooling air path is in a constant dry state. This is because y is constant and stable. Second, even if the circulating air volume fluctuates due to filter clogging or the NRN pressure fluctuates and the exhaust temperature from the drum changes, in the case of the present invention, the temperature of the exhaust gas from the drum changes. The temperature after passing through the dehumidifier in the circulation air path or cooling air path also changes, and the temperature difference remains the same in any case.

In this manner, the present invention is capable of detecting a constant degree of dryness and terminating drying, regardless of external factors such as outside air temperature or load amount. In particular, even when a large amount of load is applied, sufficient drying can be achieved.

[Brief explanation of the drawing]

The drawings show the present invention, and FIG. 1 is a front view of the circulating clothes dryer, FIG. 2 is a rear view of the same with the back plate removed, and FIGS. 3 and 4 are the parts shown in FIG. 5 is a control circuit diagram, 6 and 7 are fluctuation curves of the temperature difference between the drum exit temperature and the dehumidifier outlet temperature, and 8 Figure 9 shows the flow chart of another embodiment. <6)...Drum (drying room), <48)...Dehumidifier, (60)...Heater, (61)...First heat-sensitive element, (62)...Second heat-sensitive element Element, (72) (73)・
・Voltage comparator, <74>...Ladder circuit, (67)・
・Microcomputer.

Claims (1)

[Claims] (1) In a circulating clothes dryer having a circulating air passage in which exhaust air from a drying chamber is cooled with a dehumidifier to remove moisture, then reheated with a heater and supplied to the drying chamber, the dehumidification of the circulating air passage is provided. a first heat-sensitive element that measures the temperature of the air before it passes through the device; and a cooling air path that cools the air by applying outside air to the dehumidifier or the temperature of the air after passing through the dehumidifier in the circulating air path. and a second heat-sensitive element that measures the temperature of the air after passing through the device, and after a predetermined period of time has elapsed from the start of operation, the difference in temperature measured by both heat-sensitive elements reaches a substantially constant value. The temperature difference is then stored as a reference value, and the drying operation is terminated when the measured temperature difference reaches a predetermined value or more than the stored reference value within a certain period of time, or after a certain period of time has elapsed thereafter. and if the measured temperature difference does not reach the predetermined value or more within the predetermined time, the predetermined 1- value is gradually increased as time elapses. How to control the machine.