JPH0556757B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a control device for a clothes dryer that automatically detects dryness.

Conventional technology Conventionally, this type of clothes dryer was manufactured by, for example,
A control device as shown in Publication No. 60-2295 was used.

Its configuration will be explained with reference to FIGS. 6 and 7. In FIG. 6, 1 detects the electrical resistance value of an electrode provided in the drum, and detects that the resistance value has exceeded a certain value for a predetermined period of time,
This is a resistance value detection device that sends a signal to the control device 2.
This control device 2 determines the operating time until the desired drying rate is reached using a pre-installed function based on the time from the start of operation until receiving this signal, and controls the heat source 3 such as a heater and the motor 4. It was something to do. An example of the above operation is shown in the seventh example.
As shown in the figure. The resistance values between the electrodes, represented by Rmax and Rmin, rapidly increase when the degree of drying of the dried material progresses to a certain degree after the start of operation. and a predetermined period
t ₁ Continuously, the operation end time T is calculated and determined using a pre-installed function based on the time t from the start of operation until the minimum value Rmin of the resistance value variation becomes equal to or higher than the set value _R0 , It was for controlling the stoppage of the heat source 3 such as the heater and the motor 4.

Problems to be Solved by the Invention In such a conventional configuration, the operating time to reach a desired drying rate is set only based on the change in the electrical resistance value between the electrodes, so the amount of cloth is When the drying temperature is low, the frequency of contact with the electrode is low from the start of operation, and the resistance value exceeds the set value even though drying has not progressed, making it impossible to accurately detect the drying state of the dried material. As a result, there was a problem in that the operation ended without drying.

Furthermore, conventionally, the time t until the resistance value between the electrodes reaches a certain value or more includes the time when the exhaust gas temperature reaches a predetermined temperature or more and a heat source such as a heater is not operating.

However, with this method, the resistance detection time is supposed to become shorter as the ambient temperature increases for cloths with the same capacity, but in reality, the frequency at which the exhaust temperature reaches the maximum predetermined value Tmax increases. Since the resistance detection time includes the time when the heat source is not operating, in other words, the time when it is not contributing to drying, the end time of operation becomes shorter as the ambient temperature becomes higher. There was a problem that it became long and over-dry.

The present invention solves these problems, even when the electrodes are infrequently contacted and the drying state of the material to be dried cannot be determined from changes in resistance, or when the ambient temperature changes. However, the purpose is to be able to finish the operation at a desired degree of dryness.

Means for Solving the Problems In order to achieve the above object, the present invention includes a plurality of electrodes provided in a drying drum, a resistance detection device that detects the electrical resistance between the electrodes, and a temperature of exhaust gas from the drying drum. an exhaust temperature detection device that has a temperature sensor that detects the temperature of and a control device that controls a heat source to adjust the temperature at the maximum temperature when the temperature detected by the exhaust temperature detection device reaches the maximum temperature in the drying drum, and the calculation device controls the temperature between the electrodes from the start of operation. The amount of time the heat source operates until the electrical resistance value exceeds the set value continuously for a certain period of time is accumulated, and if this accumulated time exceeds the set time, the amount of time the heat source operates from the start to the end of operation according to the accumulated time. is calculated and set, and if the cumulative time is less than the set time, the time that the heat source operates from the start of operation to the end of operation is calculated and set based on the time from the start of operation until the temperature sensor reaches the maximum temperature inside the drying drum. However, the control device terminates the operation based on the time from the start to the end of operation calculated and set by the calculation device.

Effect With this configuration, even if there are few objects to be dried and the frequency of contact between the objects and the electrodes is small and it is not possible to set the operation end time by detecting the resistance of the electrodes, the exhaust temperature can be adjusted from the start of operation until it reaches a certain set temperature. Focusing on time, this time becomes longer as the moisture content of the object to be dried increases and as the ambient temperature decreases, regardless of the frequency with which the object to be dried comes into contact with the electrode.
Therefore, if you set the operation end time based on the exhaust temperature detection time from the start of operation until the exhaust temperature reaches a certain set temperature, the resistance value when the dried material comes into contact with a small capacity electrode can be reduced. It is possible to detect small amounts of dryness without depending on the accidental phenomenon of change. In addition, the calculation setting device integrates the time that the heat source operates until the electrode resistance and electrical resistance exceed the set value continuously for a certain period of time, so if the ambient temperature is high and the resistance value exceeds the set value, it will dry out. When the temperature inside the drum reaches the maximum temperature, only the time during which the heat source is operated to maintain the maximum temperature (excluding the time when the heat source is stopped) is measured. Therefore, even if the amount of material to be dried is the same, there will be a difference in the cumulative time depending on whether the ambient temperature is high or low, and it is possible to obtain a measurement time that correlates to the ambient temperature, and operate based on this measurement time. By completing the drying process, drying can be completed without being affected by the ambient temperature.

Examples Examples of the present invention will be described below in Figures 1 to 5.
This will be explained with reference to the figures. In FIG. 2, reference numeral 5 denotes a rotating drum forming a drying chamber, which is rotatably supported within an outer box 6, and its rotation causes the drying material inside to be removed.
Rotate and fall. Reference numeral 8 denotes a motor provided inside the outer box 6, which rotates the rotary drum 5 via a belt 9 and also rotates the fan case 1 via a belt 10.
Rotate the fan 12 in 1.

When the fan 12 is rotated, the air passes through the intake port 13 and is converted into hot air by the heater 14.
It enters the rotating drum 5, heats the material to be dried 7, and removes moisture. Thereafter, after passing through a filter 15 provided on the rear surface of the rotating drum 5, the air is discharged outside the machine through the fan case 11 and the exhaust port guide 20.

The object to be dried 7 is dried by the series of operations described above. 16 is an electrode fixed to the drum support plate 18 via an insulator 17 such as resin;
The electrical resistance of the material to be dried 7 is detected between the drum support plate 18 and the drum support plate 18. A temperature sensor 19 is installed inside the fan case 11 and detects the temperature of the exhaust gas from the drum.

Next, automatic control of clothes drying will be explained. First, when a certain amount of material 7 to be dried is contained in the drum 5, the material 7 to be dried is always in contact with the electrode 16 and the drum support plate 18.
As shown in the figure, although there is a wide range of variation in the resistance value between the electrodes, since the surface of the object to be dried is wet at the beginning of operation, the resistance value is smaller than the set resistance value R ₀ . Then, as the drying progresses and a certain drying rate is reached, the resistance value rapidly increases, and the resistance value continuously exceeds the set resistance value R ₀ for a certain period of time t ₁ . It is assumed that resistance is detected at this time, and the resistance detection device 21 shown in FIG. Then, in the calculation device 22, based on the resistance detection time t,
Calculate the cumulative amount of time that a heat source such as a heater must operate before the end of operation, and calculate ΔT ₁ , ΔT ₂ . . . as shown in Figure 3.
When the sum of ΔT ₄ becomes equal to T, the control device controls the motor and heater and ends the operation.

Next, if there is less material to be dried than in the above case or the ambient temperature is high, the exhaust temperature from the drum tends to rise and reaches the maximum exhaust temperature Temax before resistance detection is performed, as shown in Figure 4. As a result, the heat source such as a heater is stopped until the temperature drops to the temperature at which the clothing returns to normal because the temperature of the clothing is high.
In the conventional detection method, the time when the heat source is stopped is also included in the resistance detection time, but the present invention uses the integrated value only for the time when the heat source is operating, and the time from then until the end of the operation is used. The calculation and control methods are the same as those described above.

Next, when the amount of material to be dried is smaller, the frequency with which the material to be dried comes into contact with the electrodes is extremely reduced, so as shown in Figure 5, the resistance value between the electrodes is A high resistance value when the drying process is not performed is detected, and the resistance detection time is recognized as the resistance detection time t even though the drying of the dried material has not progressed at all. As a result, if the operating time T is set based on the resistance detection time t, the product will not be dried or the drying rate will vary greatly. Therefore, in such a case, focusing on the time ΔT ₁ until the exhaust temperature reaches the maximum temperature Temax, if the resistance detection time is small,
Compared to setting the operating time T based on the accidental phenomenon of contact with the electrode or not, the exhaust temperature rise time is It can be seen that there is little quantitative variation. Therefore,
When the capacity is very small, the calculation device 22 sets the operating time based on the temperature detection time until the exhaust temperature detection device 23 shown in FIG. 1 reaches a predetermined temperature,
Based on this setting, the control device 24 controls the motor 25,
By controlling the heater 26, the operation can be stopped when a desired drying rate is reached. The difference between the case based on the resistance detection time and the case based on the temperature detection time is the resistance detection time t.
This is done by In other words, if the resistance detection time t is smaller than a certain certain time _t0 , it is determined that there is a small amount of material to be dried, and the operating time is set based on the temperature detection time, and if the resistance detection time is greater than the certain certain time The operation time is set based on the resistance detection time.

Effects of the Invention As described above, according to the present invention, the arithmetic unit integrates the time during which the heat source is operated from the start of operation until the electrical resistance value between the electrodes exceeds the set value continuously for a certain period of time, and calculates the cumulative time. exceeds the set period,
In other words, if the amount of material to be dried is not small, the time for the heat source to operate from the start of operation to the end is calculated and set using the cumulative time, and if the material to be dried is small, that is, if the cumulative time is less than the set time, In this method, the time required for the heat source to operate from the start of operation to the end of operation is calculated based on the time from the start of operation until the temperature sensor reaches the maximum temperature inside the drying drum, so electrical resistance detection is possible even when the amount of material to be dried is small. Even if this is not possible, the operating time can be set to match the amount of material to be dried, and the drying condition can be maintained in good condition. In addition, the arithmetic setting device integrates the time that the heat source operates until the electrical resistance value between the electrodes exceeds the set value continuously for a certain period of time, so it is possible to obtain the measurement time that correlates to the ambient temperature. By terminating the operation based on the measurement time, drying can be completed without being affected by the ambient temperature.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a control section of a clothes dryer according to an embodiment of the present invention, FIG. 2 is a longitudinal sectional view of the same clothes dryer, and FIGS. 3, 4, and 5 are a block diagram of the clothes dryer. Characteristic diagrams showing the relationship between operating time, exhaust temperature, drying rate, and resistance value between electrodes, Figure 6 is a block diagram showing the control section of a conventional clothes dryer, and Figure 7 shows the operation of a conventional clothes dryer. FIG. 3 is a characteristic diagram showing the relationship between time, exhaust temperature, drying rate, and resistance value between electrodes. 21...Resistance detection device, 22...Arithmetic device, 2
3... Exhaust temperature detection device, 24... Control device, 2
5...Motor, 26...Heater.

Claims (1)

[Claims] 1. A plurality of electrodes provided in the drying drum, a resistance detection device that detects the electrical resistance between these electrodes, an exhaust temperature detection device that has a temperature sensor that detects the temperature of the exhaust gas from the drying drum, and both of the above-mentioned detection devices. A computing device calculates and sets the time from start to finish of operation based on signals from the computing device, and controls the heat source and drive source based on signals from the computing device. A control device is provided to control the heat source and adjust the temperature at the maximum temperature when the maximum temperature is reached, and the calculation device is configured to control the heat source until the electric resistance value between the electrodes continuously exceeds the set value for a certain period of time from the start of operation. The operating time is accumulated, and if this accumulated time exceeds the set time, the time that the heat source operates from the start of operation to the end is calculated and set based on the accumulated time, and if the accumulated time is less than the set time, the operation is stopped. Based on the time from the start until the temperature sensor reaches the maximum temperature inside the drying drum, the time that the heat source operates from the start to the end of the operation is calculated and set, and the control device starts the operation calculated and set by the calculation device. A clothes dryer control device that terminates operation based on the time from start to end.