JPH04232000A - Drum type dryer - Google Patents

Abstract

PURPOSE:To eliminate the uneven drying by loosening the washing in a drum by rotating backward the drum, when a detected temperature difference becomes above a prescribed temperature in a constant rate drying period, and rotating forward the drum, when the temperature difference becomes below the prescribed temperature. CONSTITUTION:An operation start command is subjected to key input and a motor 32 and a heater 30 are driven and a drum 13 rotates forward. As soon as constant rate drying is started, a detected temperature difference of temperature sensors 39, 4O is stored as A, and thereafter, its detected temperature difference At is detected continuously, and At-A is calculated as dA. In the case dA is <=1, the drum 13 rotates forward continuously, and in the case At does not reach a prescribed value, the operation is returned to a first process again. On the other hand, in the case dA is larger than 1, the drum 13 is rotated backward, and when this operation is repeated and the temperature difference At becomes larger than the prescribed value, the heater 30 is turned off, the washing is cooled by cold air and the drying operation is finished. According to this drying method, uneven drying is reduced and the drying efficiency is improved, and the drying time is also shortened.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a drum dryer for drying laundry.

0002

2. Description of the Related Art Conventional drum dryers are known in which the drum is rotated forward and backward during drying in order to uniformly dry laundry.

0003

[Problems to be Solved by the Invention] However, in conventional dryers like this, the ratio of the forward and reverse periods is constant, so the amount of laundry changes depending on the volume and material of the laundry, the degree of unevenness in the drum, etc. There was a problem that uneven drying remained. The present invention has been made in consideration of these circumstances, and provides a drum dryer that prevents uneven drying by controlling the rotational direction of the drum depending on the temperature of the warm air in the drum.

0004

[Means for Solving the Problems] A drum-type washing machine of the present invention includes a rotatably supported rotary drum having an air supply port and an exhaust port, and a rotary drum having an air supply port and an exhaust port located outside the rotary drum. an air circulation path connected to the exhaust port, a fan that cools and dehumidifies the air discharged from the exhaust port and supplies the air to the air supply port, a heater provided in the air supply port, and a motor that drives the rotating drum and the blower fan. , a first temperature sensor that detects the temperature of the air discharged from the exhaust port, a second temperature sensor that detects the temperature of the air supplied to the heater, and the temperature detected by the first temperature sensor and the second temperature sensor, respectively. Drying operation is performed by rotating the drum in the forward direction while calculating the difference in temperature between the drums, and a control means for rotating the drum in the reverse direction during a period in which the temperature difference exceeds the predetermined temperature after a predetermined time after the start of the operation.

[0005]

[Operation] Drying operation is performed by rotating the drum in the forward direction, and when a predetermined period of time has elapsed after the start of operation, the drying process enters a constant rate drying period. During this period, when the temperature difference between the temperatures detected by the first and second temperature sensors becomes equal to or higher than a predetermined temperature, the drum is rotated in the reverse direction, and when the temperature difference becomes equal to or less than the predetermined temperature, the drum is rotated in the forward direction. As a result, the laundry in the drum is loosened appropriately, and drying is performed uniformly and evenly.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below based on embodiments shown in the drawings. This invention is not limited by this. FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention, in which 1 is a machine frame of a clothes dryer 2, 3 is a clothes input port provided at the center of the front of this machine frame 1, and 4 is a machine frame 1. This is a rear plate fixed to the rear surface of the air conditioner, and has an external air introduction hole 5 in the center and an outlet 6 in the lower part. 7 is a door for opening and closing the input port 3; 8 is an annular sheet metal drum support plate installed in the machine frame 1 so as to surround the input port 4; 9;
10 is a support plate installed laterally at the rear of the machine frame 1 so as to be spaced apart from the rear plate 5; 10 is a fan casing fixed to the support plate 9;
1 and a fan chamber 12. 13 is drying room 1
It is a horizontal shaft-type drum disposed in a drum 2, with its front opening facing the input port 4, supported by a drum support plate 8 via felt, etc., and its rear side rotating around a shaft 14. freely supported. 15... is a drying air outlet provided at the center of the rear surface of the drum 13, 16 is a lint filter that covers this outlet 15, 17... is a drying air inlet provided at the lower part of the drum support plate 8, and 18 is a drying air outlet provided on the support plate 9. A communication port 19 provided to communicate the drying chamber 11 and the fan chamber 12 is a sealing member for reliably sending air from the drying air outlets 15 to the communication port 18.

Reference numeral 20 denotes a disk-shaped synthetic resin double-sided fan fixed to a shaft 14 in the fan chamber 12, with a circulation fan 21 located on the drying chamber 11 side and a cooling fan 21 located on the rear plate 4 side. The fans 22 are formed integrally with each other in a radial manner, and a pulley 23 is provided at the center on the side of the cooling fan. 24 is fan casing 10
This is a synthetic resin partition plate provided so as to surround the double-sided fan 20, and by housing the double-sided fan 20 in the circular opening at the center of the partition plate 24, the partition plate 24 and the double-sided fan 20 can be used together. The inside of the fan room 10 is made into a drying air path 2.
5 and a cooling air passage 26.

A group of concentric rotating grooves 27 opening toward the drying air passage 25 is integrally formed on the periphery of the double-sided fan 20, while a cooling air passage 26 is formed on the inner periphery of the partition plate 24.
A concentric fixing groove group 28 that opens toward is integrally formed, and the rotating groove group 27 is loosely fitted into the fixing groove group 28 without contacting each other. That is, the rotating groove group 27 and the fixed groove group 28 form a labyrinth connection.

A drying duct 29 connects the lower part of the drying air passage 25 and the drying air inlet 17, and a heating heater 30 is disposed inside thereof. 31 is a discharge port provided at the bottom of the duct 30 for discharging the dehumidified water condensed in the duct to the outside of the machine; 32 is a drive motor, which is connected to the pulley 23 via a small pulley 33 and a belt 34; A pulley 35 and a belt 3 are connected to the drum 13.
6.

During drying, the drum 13 is rotated at low speed and the double-sided fan 20 is rotated at high speed in one direction by the driving force of the drive motor 32, and at the same time, the heater 30 is energized.
The drying air is heated.

[0011] As a result, the wind generated by the rotation of the circulation fans 21...
3 and exchanges heat with the material to be dried in the drum 13. In addition, due to the rotation of the cooling fan 22..., the introduction hole 5
... is introduced into the cooling air passage 26, and is led out from the outlet 6, at which time the double-sided fan 20 is cooled. After heat exchange, the drying air is cooled in contact with the double-sided fan 20, and moisture in the drying air is condensed, flows down in the drying air path 25, and is discharged from the outlet 31. During this time, drying air path 2
5 and the cooling air passage 26 are sealed by a birins connection.

Reference numerals 37 and 38 are double idlers for efficiently bringing the belt 36 into contact with the pulley 35 to prevent slippage. Since two idlers are used, the drum 13 rotates without any problem even if the motor is reversed.

39 is a temperature sensor that measures the temperature at the drum outlet, and 40 is a temperature sensor that measures the temperature at the heater inlet.

FIG. 2 is a block diagram of the control circuit of the embodiment shown in FIG. The heater 30, the motor 32, and the display section 43 are driven via the drive section 42 according to a preset program.

FIG. 3 is a graph showing temperature characteristics during unidirectional rotation (normal rotation). The vertical axis is the temperature difference between the drum outlet and the heater inlet, and the horizontal axis is the operating time. With normal loads such as towels and underwear, as shown by the solid line, the pre-drying period, constant rate drying period, and decreasing rate drying period clearly appear, and the temperature difference A is read in 15 minutes of operation time, and the temperature difference is further increased. Drying ends at point C, where B increases. There is no problem at all even if the drum is not turned over. However, when drying large items of clothing such as sheets, as shown by the dotted line in the figure, the temperature difference increases and returns to the original state repeatedly, and at the final point D, the drying may stop. The reason why the temperature difference fluctuates by dA is because the sheets repeatedly become tango-shaped and unravel, and if they do not eventually unravel, the interior will not dry as shown at point D and will stop. However, when the dryer according to the present invention detects dA shown in FIG. 3 during operation, it determines that there are sheets inside and rotates the drum in the reverse direction. d
If A=0, it is determined that there are no sheets, and the sheet is not turned over.

FIG. 4 is a flowchart illustrating the operation of the embodiment shown in FIG. In FIG. 4, an operation start command is entered using a key (step 101). The motor 32 and heater 30 are driven (step 102), and the drum 1
3 rotates forward (step 103). At the same time that constant rate drying starts after 15 minutes of operation time has elapsed, temperature sensors 39 and 40
The detected temperature difference is stored as A (step 105).
. After that, the detected temperature difference At between the temperature sensors 39 and 40 is continuously detected (steps 106 and 107),
At-A is calculated as dA (step 108). If dA is less than 1 (step 109), the drum 13 continues to rotate normally, and if At does not reach the predetermined value (A+B) (step 112), the routine returns to step 10.
Return to 4. If dA is greater than 1 in step 109, the drum 13 is reversed (step 111);
The routine continues to step 112. When the stiffening operation is repeated and the temperature difference At becomes larger than the predetermined value (A+B),
The heater 30 is turned off, the laundry is cooled with cold air (step 113), and the drying operation ends.

FIG. 5 is a rear view of the embodiment shown in FIG. 1, and when viewed from FIG. 5, the counterclockwise (direction of arrow K) rotation is forward rotation, but in the drying process, the forward rotation period is Since the rotation period is longer than the reverse rotation period, the laundry tends to collect on the right side of the bottom of the drum 13. Therefore, the heater 30 is correspondingly arranged on the right side of the bottom of the drum 13 as shown in FIG. 5 to improve the drying efficiency.

Further, in the above operation control, the reversal time may be determined using fuzzy inference from the temperature difference during operation and the rate of change over time of the temperature difference.

In this embodiment, control was carried out by examining the difference between the drum outlet temperature and the heater inlet temperature, but the same effect can be obtained by controlling only the temperature at the drum outlet. (Setting the difference between the drum outlet and the heater inlet makes it easier to deal with changes in room temperature, such as when a window is suddenly opened.) Furthermore, in this embodiment, since the clothes are loosened by reversing the drum, there is no need for the baffle to have a special shape, and the substantial volume of the drum increases.

[0020]

[Effects of the invention] The drum is rotated forward and backward based on changes in the hot air temperature that occur depending on the type and form of the clothes to be dried.
Drying unevenness is reduced, drying efficiency is improved, and drying time is also shortened.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a block diagram of a control circuit of the embodiment shown in FIG. 1;

FIG. 3 is a graph showing hot air temperature versus drying time.

FIG. 4 is a flowchart showing the operation of the embodiment shown in FIG. 1;

FIG. 5 is a rear view of the embodiment shown in FIG. 1;

[Explanation of symbols]

13 Drum 20 Fan 29 Drying duct 32 Drive motor 39,40 Temperature sensor

Claims (1)

[Claims] 1. A rotating drum rotatably supported having an air supply port and an air exhaust port, an air circulation path connecting the air supply port and the air exhaust port externally to the rotating drum, and an air circulation path that connects the air supply port and the air exhaust port externally to the rotating drum, and a a fan that cools, dehumidifies and supplies the air to the air supply port;
A heater provided at the air supply port, a motor that drives a rotating drum and a blower fan, a first temperature sensor that detects the temperature of air discharged from the exhaust port, and a first temperature sensor that detects the temperature of the air supplied to the heater. Drying operation is performed by rotating the drum in the forward direction while calculating the difference between the temperatures detected by the second temperature sensor, the first temperature sensor, and the second temperature sensor, respectively, and the temperature is increased after a predetermined time after the start of the operation. A drum dryer equipped with a control means for rotating the drum in reverse during a period when the temperature difference is above a predetermined temperature.