JP3166363B2 - Clothes dryer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clothes dryer, and more particularly to a clothes dryer for detecting the degree of clogging of a filter for collecting lint, cotton dust and the like generated in a drying drum.

[0002]

2. Description of the Related Art A clothes drier includes a drying drum rotatably supported so as to accommodate a material to be dried in a machine frame, a driving device for rotating the drying drum, and an air passage in a ventilation passage including the drying drum. A drying device, a heating device for heating air flowing in the drying drum, and a filter cover detachably provided to cover an air outlet of the drying drum and forming a dust collecting chamber. The air inside is guided from the ventilation window formed in the filter cover to the air outlet through the dust collection chamber, and the lint filter provided here is configured to collect lint, cotton dust and the like in the flowing air. .

When the lint filter is dried in a clogged state, as the amount of ventilation decreases, as shown in FIG. 5, the amount of heat generated by the PTC heater, which is the heating source, decreases, and the drying time decreases as shown in FIG. A long-running trouble occurs. In order to prevent this problem, the conventional product detects the amount of heat generated by the PTC heater by detecting the change in current with a current sensor comprising a current transformer as shown in FIG. 7 and notifies the user when the lint filter is clogged. A notification device is provided.
However, since the current of the PTC heater differs depending on the power supply voltage characteristics shown in FIG. 7 and the outside air temperature characteristics shown in FIG. 8 even when the cint amount of the same lint filter is clogged, the power supply voltage and the outside air temperature are corrected. Therefore, many correction errors occur and the accuracy is extremely poor. In addition, a power supply voltage correction circuit and a temperature sensor for detecting the outside air temperature are required, which is expensive.

[0004]

Therefore, the current value of the prior art PTC heater is detected by a current sensor.
The lint filter clogging notification system including the correction of the power supply voltage and the correction of the outside air temperature by the temperature sensor has a low accuracy and is an expensive detection method.

An object of the present invention is to improve the accuracy by an inexpensive detection method.

[0006]

According to the present invention, there is provided a frame, comprising:
A drying chamber for drying the clothes provided inside the frame, the drying
A motor for rotating the chamber, a heating element arranged on the air suction side of the drying chamber, and lint and the like in the drying chamber are collected.
Lint filter for collecting and circulating air in the drying chamber
In a clothes dryer having a two-sided fan that leads to the heating element through a flow path, cooling from loss-of-rate drying in drying operation to cooling
The temperature of the air that has passed through the lint filter during drying is measured, compared with the temperature of the air at the time of the lint filter clogging that has been obtained in advance, and the clogging of the lint filter is determined and reported. I do.

[0007]

[Function] The maximum temperature of the drum outlet air temperature in the decreasing rate drying section is detected by a temperature sensor composed of a thermistor and compared with the lint filter clogging determination temperature stored in the microcomputer. If the temperature is lower than the judgment temperature, it is notified that the lint filter is clogged.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. First, the configuration of a series of dryers will be described with reference to FIG. A back cover 2 is fixed to the rear surface of the outer frame 1. A clothing inlet 3 formed on the front of the outer frame 1 and a door 4 for opening and closing the entrance 3 are located on the front of the outer frame 1, and a metal drum support plate 5 fixed to the outer frame 1 and a machine. A drum 7 serving as a drying chamber is rotatably supported by a rear bearing 6 disposed at the rear of the frame 1. The rear surface of the drum 7 forms a hot air outlet 8 composed of a number of holes. A circulation path 10 is formed to communicate with a hot air inlet 9 formed at a lower portion of the drum support plate 5 from a vent 12 of a fan casing 11. Honeycomb heater 13 composed of a positive temperature coefficient thermistor facing hot air inlet 9
Is accommodated in an L-shaped duct 14 fixed to the drum support plate 5. In the fan casing 11, a heat exchange type double-sided fan 16 is rotatably supported on the rear bearing 6 via metal. An electric motor 18 is disposed in the upper portion of the outer frame 1, and the drum 7 is rotated by a pulley including an idler pulley and a belt 24, and the double-sided fan 16 is rotated by a pulley belt. A lint filter 19 is installed from the inside so as to cover the hot air outlet 8 of the drum 7, and a filter cover 27 is mounted so as to cover the lint filter 19. A temperature sensor 20 composed of a thermistor and a humidity sensor 22 are provided at a position facing the hot air outlet 8 of the fan casing 11 in the circulating air passage to detect a change in the state of the dry air, and to detect an outside air temperature. A temperature sensor 21 composed of a thermistor is attached to the cooling air inlet 2a of the back cover 2. A control device 25 for performing a series of drying operations is disposed at a front portion inside the outer frame 1. An operation unit 26a and a display unit 26b are arranged on the front surface of the outer frame 1.

The operation will be described below. When driving,
First, the door 4 is opened and the dehydrated clothes are stored in the drum 7 and a power source (not shown) is turned on, the electric motor 18 and the heater 13 are energized to rotate the drum 7 at a low speed, and the double-sided fan 16 rotates at a high speed. I do. The air in the circulation path 10 is heated by the heater 13 and is turned into hot air inlet 9 as high-temperature dry air.
It is further sucked into the drum 7. The high-temperature dry air sent into the drum 7 comes into contact with the clothes in the drum 7 and promotes the evaporation of moisture contained in the clothes, and becomes high-temperature and high-humidity air, and the lint filter 19 in the filter cover 27 removes cloth dust. After being collected, it is sucked into the double-sided fan 16 in the fan casing 11. The outside air sucked into the double-sided fan 16 from the cooling air inlet 2a of the back cover 2 is cooled to a temperature lower than the dew point temperature, and condensed water is generated on the circulation path side of the double-sided fan 16. The generated condensed water is discharged out of the machine through a drain port 15 of the circulation path 10. The circulating air that has lost a part of the moisture when passing through the double-sided fan 16 becomes dehumidified air and is heated by the heater 13 provided in the L-shaped duct 14, and then as high-temperature dry air into the drum 7 again. Sent and used for drying clothes.

[0010] The clogging of the lint filter 19 will be described. FIG. 2 shows the fan casing 11 in the drying process.
Temperature sensor 20 attached to the hot air outlet 8
FIG. The solid line indicates the temperature change when the lint filter 19 is not clogged, and the dotted line indicates the temperature change when the lint filter 19 is clogged. As shown in FIG. 2, when the lint filter 19 is clogged, the temperature does not rise. FIG. 3 shows the relationship between the maximum temperature from the rate-decreasing drying to the cooling drying in FIG. 2 and the degree of clogging of the lint filter 19. FIG. 4 shows a block diagram of the electric system. The microcomputer of the control device 25 stores the determination temperature of clogging, and stores the temperature sensor 2 in the drying process.
The maximum temperature of the temperature sensor 20 is compared with the maximum temperature of 0, and if the maximum temperature of the temperature sensor 20 is equal to or lower than the determination temperature, the clogging of the lint filter 19 is displayed on the display unit 26b from the cooling and drying step to notify the same.

As shown in FIG. 3, since the relationship between the degree of clogging of the lint filter 19 and the maximum temperature is slightly different depending on the outside air temperature, the accuracy is further improved by adding the outside air temperature correction by the outside air temperature detecting temperature sensor 21. .

In one embodiment, the maximum temperature of the temperature sensor 20 in the drying process is detected to make a comparison and determination. However, a comparison and determination method using the average value of the temperature sensor 20 in the drying process at regular intervals is also used. The same effect is obtained.

[0013]

According to the present invention, an existing temperature sensor for temperature control is used in combination with the lint filter clogging detection, so that the current is exclusively used for the lint filter clogging detection as in the conventional current detection method. This eliminates the need for a sensor and eliminates the need for power supply voltage correction, etc., and provides an extremely inexpensive detection method. Further, the conventional current detection method requires a current sensor (current transformer), a temperature sensor (thermistor) for temperature correction, and a circuit for power supply voltage correction. On the other hand, the temperature detection method of the present invention is an extremely accurate detection method because only the accuracy error of the temperature sensor (thermistor) occurs.

[Brief description of the drawings]

FIG. 1 is a sectional view of a clothes dryer showing one embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a temperature change downstream of a lint filter in a drying process.

FIG. 3 is a characteristic diagram of a degree of clogging of a lint filter and a maximum temperature in a drying process.

FIG. 4 is an electrical configuration block diagram.

FIG. 5 is a characteristic diagram of a degree of clogging of a lint filter and a calorific value of a heater.

FIG. 6 is a characteristic diagram of a degree of clogging of a lint filter and a drying time.

FIG. 7 is a characteristic diagram of a power supply voltage and a heater current.

FIG. 8 is a characteristic diagram of outside air temperature and heater current.

[Explanation of symbols]

2a: cooling air inlet, 7: drum, 8: hot air outlet, 11 ...
Fan casing, 13: heater, 16: double-sided fan,
18 ... electric motor, 19 ... lint filter, 20 ... temperature sensor, 21 ... temperature sensor, 25 ... control device, 26b ... display unit, 27 ... filter cover.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Takashi Tomita 1-1-1, Higashitaga-cho, Hitachi City, Ibaraki Prefecture Living Equipment Division, Hitachi, Ltd. (56) References JP-A-2-128799 (JP, A JP-A-4-256799 (JP, A) JP-A-3-6313 (JP, Y2) (58) Fields studied (Int. Cl. ⁷ , DB name) D06F 58/28

Claims (1)

(57) [Claims] 1. A frame, a drying chamber for drying clothes provided in the frame, and a motor for rotating and driving the drying chamber.
A heating element that is disposed on the air suction side of the drying chamber, the
A lint filter for collecting lint and the like in the drying chamber,
The air in the drying chamber is guided to the heating element via a circulation channel.
In a clothes dryer having a double-sided fan, the temperature of air passing through the lint filter from drying at a reduced rate to cooling and drying in the drying operation is measured, and the temperature of the air at the time of clogging the lint filter, which is obtained in advance, is measured. A clothes dryer characterized in that clogging of the lint filter is determined and reported as compared with the above.