JPH03126497A - Controller for clothing dryer - Google Patents

Abstract

PURPOSE:To always perform a blanket drying course without malfunction and with stable and high accuracy by constituting the controller so that a cold air operation is performed once when a temperature difference shows a value exceeding a prescribed value and performing a drying operation after the inside of a drum is sufficiently cooled even when an operation is started at a state where the inside of the drum is not sufficiently cooled. CONSTITUTION:An operation control part 21 inputs a discharge temperature from a discharge temperature detecting means 17 and a room temperature from a room temperature detecting means 19, and computes the temperature difference between the discharge temperature and the room temperature, and judges whether or not the temperature difference arrives at the prescribed value T0. When no temperature difference arrives at the prescribed value T0, control is performed repeatedly, and when it arrives at the prescribed value T0, the energizing of a heater 3 is stopped. In other words, a heating means sets a low output state by only a heater 4, and maintains such state for constant time. Furthermore, the cold air operation in which the heater 4 is turned off and only the motor 2 is operate is performed. Such a cold air operation is executed for constant time, and after that, the motor 2 is turned off, then, the operation is completed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a control device for a clothes dryer that is capable of drying items such as blankets that have a low heat resistance temperature.

Conventional technology Conventionally, when drying cloth with a low heat-resistant temperature such as a blanket in a clothes dryer, the temperature of the cloth does not rise due to the moisture generated from the cloth when the cloth is damp, and the heat causes the cloth to dry. However, as the cloth approaches drying, the moisture content decreases and the temperature of the cloth increases, causing discoloration, deformation, and shrinkage of the cloth and other fibers that are exposed to hot air. To solve this problem, the output of the heating means is controlled, drying is performed at low output at first, the temperature of the air discharged from the drum and the room temperature are detected, and when the temperature difference reaches a predetermined value, the heating means is further turned on. We are considering a clothes dryer that is configured to further reduce the output and is equipped with a blanket drying course that can dry items with low heat resistance.

Problems to be Solved by the Invention However, in the case of this configuration, after drying ordinary clothes by first setting a strong output of the heating means, the blanket course is selected immediately before the inside of the drum has been sufficiently cooled. However, when drying is started, if the temperature difference between the temperature of the air discharged from the drum and the room temperature is already above a predetermined value, the output of the heating means is controlled low, resulting in the problem that drying cannot be performed. Was.

In view of the above problems, it is an object of the present invention to enable drying without malfunction even if a blanket course is started in a state where the temperature inside the drum is high.

Means for Solving the Problems The technical means of the present invention for achieving the above object includes: heating means for supplying hot air into the drum; and discharge temperature detection means for detecting the temperature of air discharged from the drum. , a room temperature detection means for detecting the room temperature, and a control means for controlling the heating means etc. to perform drying control based on the temperature difference between the discharge temperature detection means and the room temperature temperature detection means, the control means detecting the discharge temperature. After the temperature difference between the detection means and the room temperature detection means reaches a predetermined value, the output of the heating means is controlled to be reduced, and when the temperature difference is above a certain value at the start of operation, the heating means is controlled to decrease. After stopping and performing the air blowing process for a certain period of time, the heating means is operated again to perform drying.

Effect: According to the above technical means, if the blanket course is selected and drying is started before the inside of the drum has cooled down sufficiently, the temperature difference between the exhaust temperature and the room temperature will exceed a predetermined value at the start of operation. Therefore, when this temperature difference is greater than a predetermined value, by performing cold air operation to lower the temperature inside the drum, highly accurate drying can be performed without malfunction.

EXAMPLE Hereinafter, an example of the present invention will be described based on the accompanying drawings.

First, the basic structure of a clothes dryer and its control device will be explained with reference to FIGS. 1 and 2.

In the figure, 1 is an AC power source, to which a motor 2 and heaters 3 and 4, which are heating means, are respectively connected. The motor 2 and heaters 3 and 4 are connected to the AC power supply 1 through a bidirectional sirinuta 5°6.7 which is a type of nutwitching element.
electricity will be supplied.

The motor 2 rotationally drives a drum 23 rotatably disposed within the main body of the clothes dryer and a heat exchange type blower 24 disposed behind the drum 23. The heat exchange type blower 24 generates circulating air A and cooling air B as shown by the arrows in FIG. Condenses the water that flows into the drain port 2.
5 to the outside of the machine. That is, the heat exchange type blower 24
functions as a dehumidifying means for removing moisture from the circulating air A. The dehumidified circulating air from the heat exchange blower 24 is heated again by the heater 3 and supplied into the drum 23. Furthermore, temperature detection means 16 are provided at various locations in the clothes dryer. Discharge temperature detection means 17 that detects the temperature of the circulating air A discharged from the drum 23, and dehumidification temperature detection means 1 that detects the temperature of the circulating air dehumidified by the heat exchange type blower 24.
and room temperature detection means 19 for detecting the temperature of the cooling air B to detect the room temperature. Specifically, these temperature detection means 16 are, for example, temperature thermistors.

The signal from the temperature detection means 16 is converted into a digital signal by an A/D converter 20 and input to an operation control section 21 comprised of a microcomputer or the like. This operation control section 21 receives a signal from the input setting section 11 . Input setting section 11
The output setting switch 12 is a heating output setting means for setting the strength of the output of the heaters 3 and 4, the course setting switch 13 is a course setting means for setting a plurality of drying control courses, and the drying operation start and temporary It is comprised of a start/-time stop switch 14 for stopping. On the other hand, a display section 22 and a load drive section 15 are connected to the output side of the operation control section 21 . The load drive section 16 includes a motor 2. Transnuta 8 performs switching control of bidirectional thyristor 6°6.7 that performs energization control of heaters 3 and 40
It consists of ゜9.10. As shown in FIG. 3, the display unit 22 displays the strength status of the heater 3.4 set by the output setting switch 12 and the drying course (standard course and blanket course) set by the course setting switch 13. do.

Next, a first embodiment of the present invention will be described based on the configuration and control device of the basic clothes dryer and FIGS. 4 to 7.

In this embodiment, when attempting to dry a blanket, which is an object to be dried with a low heat resistance temperature, as shown in FIG. Then, in step 31, the start/-time stop switch 14 is pressed. Upon receiving this start signal, the operation control section 21 sends a signal to the load drive section 15 in step 32 to drive the motor 2. Operate heaters 3 and 4.

Next, the operation control unit 21 inputs the discharge temperature from the discharge temperature detection means 17 and the room temperature from the room temperature detection means 19 in step 33, calculates the temperature difference between the discharge temperature and the room temperature in step 34, and calculates the temperature difference between the discharge temperature and the room temperature. Predetermined value T. Determine whether it has been reached. If the temperature difference has not reached the predetermined value T0, the above control is repeated, and when the temperature difference reaches the predetermined value T0, the energization of the heater 3 is stopped in step 35. That is, the heating means is set to a low output state using only the heater 4, and this state is set in step 36.
to be maintained for a certain period of time. Furthermore, in step 37, the heater 4
is also turned off, and a cold air operation is performed in which only the motor 2 is operated for a certain period of time in step 38. After performing this cold air operation for a certain period of time, the motor 2 is set to 0FFL in step 39, and the motor 2 is set to 0FFL in step 4.
End the operation with o.

FIG. 6 shows the change in the discharge temperature T2 from the discharge temperature detection means 17 and the room temperature T2 from the room temperature detection means 19 with the drying time. In the section B in the figure, a constant discharge temperature is maintained during the process in which water from the material to be dried gradually evaporates. B
This section is a process in which the moisture content in the material to be dried decreases and the amount of heat used to evaporate the moisture in the material to be dried is small, and the discharge temperature begins to rise. In this embodiment, as shown in FIG. 6, the temperature difference between the discharge temperature T1 and the room temperature T2 is detected, and when this temperature difference reaches a predetermined value T0, the heater 3 is turned off.
FF is turned on to lower the heating output, and the discharge temperature is lowered as shown in section C in the figure. Therefore, the temperature inside the drum 23, which is correlated with the discharge temperature, can also be lowered, and the drum 2
To suppress the thermal influence on the items to be dried in a clothes dryer, and even items to be dried with low heat resistance temperature can be dried in a clothes dryer without causing fabric damage or fabric shrinkage.

Here, the reason why drying is controlled based on the temperature difference between the discharge temperature and the room temperature is that when the room temperature is high, the discharge temperature is also high, and on the other hand, when the room temperature is low, the discharge temperature is also low. This is because if an attempt is made to detect the point in time when moisture decreases, an error will occur in the detection point due to the influence of room temperature, and there is a possibility that the material to be dried may be exposed to high temperature conditions.

In the above embodiment, drying was carried out from a state where the temperature inside the drum 23 was approximately equal to room temperature, and when the heaters 3 and 4, which are heating means for ordinary clothes, were initially set to high,
The temperature T1 of the water discharged from inside the drum 23 is high, especially near the end of drying, reaching 65 to 70°C. Normally, after the drying process, there is a blowing process to cool down the temperature inside the drum, but for some reason, the user may change the clothes while the inside of the drum has not cooled down sufficiently. If you put the blanket in the drum 23 and set the blanket course to dry the blanket immediately and start operation, the temperature discharged from the drum 23 will be high.
If the temperature difference from the room temperature exceeds the predetermined value T or approaches T0, the process shifts to section C shown in Figure 6, that is, the section in which drying is performed by lowering the heating output, and the correct blanket course cannot be used for drying. Since the drying process is not carried out and the material to be dried cannot be dried, a sequence is added to prevent false detection.

This embodiment will be explained below with reference to FIG. Step 3
Since the operations from o to 40 are the same as those in the flowchart shown in FIG. 4, they are given the same numbers.

In step 33, the discharge temperature is detected from the discharge temperature detection means 17.
The room temperature is input from the room temperature detection means 19, and step 34
The temperature difference between the discharge temperature and the room temperature is calculated, and it is determined whether the temperature difference has reached a predetermined value T0. The temperature difference is a predetermined value T
If the value has not reached 0, repeat the above control and set the predetermined value T0
When this time is reached, it is determined in step 41 whether a certain period of time (for example, 3 minutes) has elapsed since the start of operation, and if more than 3 minutes have elapsed, the process moves to the next step 35 and subsequent steps. If it is within 3 minutes, the heater 3.4 is de-energized in step 42, cool air is operated for a certain period of time in step 43, and then step 4
In step 4, the heaters 3 and 4 are energized again to start drying again, and the control from step 33 onwards is repeated.

Effects of the Invention As is clear from the above embodiments, the present invention provides the following effects.

In other words, in a device that controls the output of the heating means based on the temperature difference between the temperature of the air discharged from inside the drum and the room temperature, even if the operation is started when the inside of the drum has not been sufficiently cooled, the temperature will change. When the difference is more than a predetermined value, the output of the heating means is not immediately controlled, but the - degree cooling air operation is performed to sufficiently cool the inside of the drum before drying operation is performed, so there is no malfunction and the high temperature is always maintained. It becomes possible to perform blanket drying coke with precision and stability.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram of a clothes dryer according to an embodiment of the present invention, Fig. 2 is a sectional view of the clothes dryer, Fig. 3 is a front view showing the operation display section of the clothes dryer, and Fig. 4 is a A flowchart showing the basic operation control, FIG. 6 is a diagram showing the temperature change between the dehumidifying temperature of the temperature detecting means and the room temperature, FIG. 6 is a diagram showing the temperature difference change between the dehumidifying temperature of the temperature detecting means and the room temperature, FIG. 7 is a flowchart showing detailed operation control. 2... Motor, 3.4... Heater, 5
, 8.7... Bidirectional thyristor, 11...
... Input setting section, 12 ... Output setting switch, 13 ... Course setting switch, 14 ...
...Start/-time stop switch, 16...Load drive section, 17...Discharge temperature detection means, 18.
... Dehumidification temperature detection means, 19 ... Room temperature detection means, 21 ... Operation control section, 22 ...
...Display section, 23...Drum, 24...
・Heat exchange type blower.

Claims (1)

[Claims] heating means for supplying hot air into the drum; discharge temperature detection means for detecting the temperature of air discharged from the drum; room temperature detection means for detecting room temperature; the discharge temperature detection means and the room temperature temperature detection means. control means for controlling the heating means and the like to perform drying control based on the temperature difference between the discharge temperature detection means and the room temperature detection means; The output of the heating means is controlled to be lowered, and if the temperature difference is greater than a predetermined value within a certain period of time after the start of operation, the heating means is stopped, and after performing the cold air process for a certain period of time, the heating means is turned on again. A control device for a clothes dryer configured to operate a drying process.