JPS6355960B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a clothes dryer with a drying end detection function for use in general households.

Conventional configuration and its problems Conventionally, this type of clothes dryer detects the electrical resistance of the clothes or the temperature inside the clothes storage, and ends drying when the value reaches a preset value. It was common to have a drying completion detection function. However, in this case, it is set to operate normally when drying clothes with the rated capacity, so if you dry clothes with less than the rated capacity, the clothes will still be dry enough when drying is detected. Therefore, it was not necessarily easy to use for users. In particular, when drying only a very small amount of clothing, such as handkerchiefs, socks, etc., it may be determined that drying is complete when the clothes are still damp, so a special setting button for small amount operation is provided. In this case, some devices are designed to continue operation for a certain period of time, knowing that the drying process may be too dry, regardless of the judgment made by the drying end detection device, and to automatically end the drying process when the drying state is appropriate. The drying end detection function was not suitable for the purpose of drying. Therefore, JP-A-58-
As shown in Japanese Patent No. 192598, there is a device that determines the amount of cloth based on the rate of change in temperature within the clothes storage and changes the drying end level based on temperature detection to improve drying end accuracy. However, in this configuration, since temperature is used as important data for determining the amount of cloth to change the level, it is not possible to determine the amount of cloth with high accuracy. In other words, in the initial stage of drying when determining the amount of cloth, if the amount of cloth is small, the temperature of the clothes storage will depend on the hot air discharge condition.For example, if the clothes are in a position that obstructs the discharged air, the temperature will drop, It has been confirmed through experiments that this results in an unstable state.
Therefore, even with the above configuration, it is difficult to finish drying with high precision.

OBJECTS OF THE INVENTION The present invention solves these conventional problems and provides an easy-to-use clothes dryer that can always accurately detect the end of drying regardless of the amount of cloth.

Structure of the Invention The clothes dryer of the present invention includes a clothes storage for storing clothes, a blower for blowing drying air, a heat source for heating the air, and a drying end detection device for detecting the drying state of the clothes. , a cloth amount detection device that detects the amount of clothing based on changes in motor drive current,
The drying end detection device includes a single or plural temperature detection elements, a reference value setting device that is set according to the output of the cloth amount detection device, and a reference value that is set according to the output of the temperature detection element or a change in the output difference. It is configured with a comparator for comparison, and can change the setting value used for detecting the end of drying according to the output of the cloth amount detecting device.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings. In Figures 1 and 3,
Reference numeral 1 denotes a clothes storage for storing clothes after dehydration, 2 a blower for blowing drying air, and 3 a heat source for heating the air. Reference numeral 4 designates a motor that rotationally drives the clothes storage 1 and the blower 2 with a belt, 5 an exhaust passage for drying air, and 6 a temperature detection element provided in the exhaust passage 5. 7 is the controller,
A drying end detection device 7a that is connected to the motor 4 and the heat source 3 and detects the end of drying based on the temperature change of the temperature detection element 6, and a cloth amount detection device that detects the amount of cloth based on changes in the drive current of the motor 4, etc. It consists of a device 7b, and control devices 7c and 7d for the motor 4 and heat source 3. The drying end detection device 7a includes a temperature detection element 6,
It consists of a reference value setting device 7e that is set according to the output of the cloth amount detection device 7b, and a comparator 7f that compares the output of the temperature detection element 6 with the reference value.

In the above configuration, the operation will be explained using FIG. 2. First, when the power switch provided in the controller 7 is turned on, electricity is started to be applied to the heat source 3 and the motor 4, and drying operation is started. As the drying progresses, the temperature detected by the temperature detection element 6 changes as shown in FIG. In FIG. 2, the solid line indicates the case of rated capacity operation, and the dashed-dotted line indicates the case of small quantity operation, and the point indicated by an x mark is the appropriate drying end point in each case.

As is clear from the figure, the temperature inside the exhaust passage 5 is
At the start of operation, the temperature rises rapidly, and then when a certain temperature is reached, the energy of the heat source and the energy of moisture evaporation in the clothing balance, and operation proceeds at a nearly constant temperature. Then, near the end of drying, the amount of water evaporation decreases, the energy balance is disrupted, and the temperature rises again. Therefore, if the temperature rise value at the final stage is set to an appropriate value _T1 , the end of drying can be detected with relatively high accuracy during rated capacity operation. However, when the amount of clothes is small, the movement of clothes inside the clothes storage is uneven, so the temperature rise near the end of drying is different from that at the rated capacity, and the setting value at the rated capacity is different from that at the rated capacity.
If the drying operation is stopped at T ₁ , the drying state will remain undried. Therefore, in the case of a small amount, by resetting the set value T ₁ to T ₁ +T ₂ , it is possible to detect the end of drying in an appropriate drying state. Therefore, for example, by utilizing the fact that the drive current of the motor 4 changes depending on the load amount, the cloth amount detection device 7b
If the amount of cloth is detected, the reference value setting device 7e can determine an appropriate setting correction value _T2 accordingly. This makes it possible to provide a highly practical clothes dryer that always accurately detects the end of drying regardless of the amount of cloth because the output of the temperature detection element 6 and the reference value are compared and controlled.

Effects of the Invention As is clear from the above embodiments, the clothes dryer of the present invention corrects the set value used for drying end detection by the drying end detecting device based on the amount of cloth detected by the cloth amount detecting device. As a result, it is possible to provide an extremely user-friendly clothes dryer that can automatically detect the end of drying in an appropriate drying state regardless of the size of the clothes.
In particular, by using a motor drive current that can stably detect the amount of cloth, and by using a temperature sensor that is stable at the end of drying to detect the end of drying, and by combining the advantages of both of the above methods, it is extremely practical.
It can be a highly accurate clothes dryer.

[Brief explanation of drawings]

FIG. 1 is a schematic longitudinal sectional view showing an embodiment of the clothes dryer of the present invention, FIG. 2 is a characteristic diagram showing temperature changes during operation of the temperature detected by the temperature detection element, and FIG. 3 1 is a block diagram of a drying end detection device. 1...Clothing storage, 2...Blower, 3...Heat source, 6...Temperature detection element, 7...Controller,
7a... drying end detection device, 7b... cloth amount detection device, 7d... control device, 7e... reference value setting device, 7f... comparator.

Claims (1)

[Claims] 1. A clothing storage for storing clothes, a blower for blowing drying air, a heat source for heating the air, and a drying end detection device for detecting the drying state of the clothes.
and a cloth amount detection device that detects the amount of clothes based on changes in the drive current of the motor, and the drying end detection device includes a single or plural temperature detection elements and a temperature detection device that is set according to the output of the cloth amount detection device. a reference value setting device,
A clothes dryer that is comprised of a comparator that compares a change in the output or output difference of a temperature detection element with a reference value, and is capable of changing a set value used to detect the end of drying according to the output of a cloth amount detection device.