JP4818406B2 - Clothes dryer - Google Patents

Description

  The present invention relates to a drum-type clothes dryer for drying washed clothes.

  2. Description of the Related Art Conventionally, a drum-type clothes dryer that dries clothes by rotating a drum containing clothes to be dried at a relatively low speed and feeding heated air into the drum is known (for example, patents). Reference 1 etc.).

  It is known that when clothes dried by such a clothes dryer are stacked, that is, when left in a state where heat dissipation is difficult, the temperature of the clothes inside increases due to a so-called heat storage action. In particular, it has been pointed out that when oils and fats remain in clothing, heat storage is promoted, and there is a risk of spontaneous ignition of clothing due to oxidative heat storage (see Non-Patent Document 1, for example). .

  In the case of home-use clothes dryers, a large amount of oils and fats hardly remain in clothes after washing, but in clothes dryers used for business purposes, machine oil or edible food is used for clothes to be washed. There may be a relatively large amount of oil soaked, and in such cases, the oils and fats may not be sufficiently removed even after washing, and a relatively large amount of oil or fat may remain in the clothes to be dried. is there. Therefore, it can be said that the possibility of spontaneous ignition due to oxidative heat storage is relatively higher than that of household clothes dryers.

  In the conventional clothes dryer, the temperature of the clothes in the drum is lowered by executing a cool-down operation in which cool air is continuously fed into the drum after the drying operation. However, the conventional cool-down operation is intended to prevent wrinkles and to lower the temperature so that the user can touch it when removing the clothes from the drum. It cannot be said that the temperature rise due to the heat storage of the internal clothing when the clothing is left or the clothing taken out from the drum is left in a stacked state is not considered. In addition, among various other situations when using a clothes dryer, consideration for abnormal temperature rise of clothes due to heat storage as described above is not always sufficient.

  For example, in a clothes dryer, the user can easily open the door even during the drying operation, but when the door is detected to be opened, the operation is interrupted immediately. Control is performed so as to stop the rotation of the drum and stop the supply of heated air to the drum. After that, when the door is closed and the user is instructed to restart the operation by operating the start key, for example, the operation is continued from the state immediately before the operation was interrupted first. Yes. Therefore, if the user opens the door during the drying operation and leaves it for a while without pressing the start key even after the door is closed, the clothing being dried is held in a stacked state in the drum. In some cases, it may lead to an abnormal temperature rise of clothing due to oxidative heat storage.

JP 2002-35491 A “Gas Usage Guide Fire Prevention”, Tokyo Gas Co., Ltd., [Online], [Search August 8, 2006], Internet <URL: http://home.tokyo-gas.co.jp/userguide/anzen /yobou/04.html>

  The present invention has been made to solve the above-described problems, and the object of the present invention is as described above in the drum under various circumstances such as when the operation is temporarily interrupted or after the operation is completed. It is an object of the present invention to provide a clothes dryer that can prevent spontaneous ignition due to heat accumulation of clothes taken out from a drum or clothes taken out from a drum and ensure high safety.

A clothes dryer according to claim 1,
A drum which is disposed in the drying chamber and accommodates clothes to be dried; a rotation driving unit which rotationally drives the drum; a blowing unit which supplies air to an air passage including the drying chamber; and the blowing unit Heating means for combusting and heating air supplied into the drying chamber, and after performing a drying operation for supplying air heated by the heating means into the drying chamber while rotating the drum, In a clothes dryer that performs a cool-down operation for supplying air that is not heated by the heating means while rotating into the drying chamber,
Temperature setting means for the user to set the temperature of the heated air supplied into the drying chamber during the drying operation;
Temperature detecting means for detecting the temperature of the air that has passed through the drying chamber;
The rotation driving means and the air blowing means so as to extend the cool-down operation for a time corresponding to the temperature set by the temperature setting means from when the temperature detected by the temperature detection means decreases to a predetermined value during the cool-down operation. Control means for controlling
It is characterized by providing.

The clothes dryer according to claim 2 is the clothes dryer according to claim 1,
The unheated air is cold air having substantially the same temperature as the outside air temperature outside the clothes dryer.

The clothes dryer according to claim 3 is the clothes dryer according to claim 1,
The higher the temperature set by the temperature setting means, the longer the cool-down operation time is extended.

  In the clothes dryer according to the first aspect of the invention, the higher the set temperature during the drying operation, that is, the higher the temperature of the clothes in the drum at the start of the cool-down operation, the lower the temperature detected by the temperature detecting means decreases to a predetermined value. The extended time for cool-down driving is longer. In particular, when a relatively large amount of clothing is contained in the drum, the clothing swollen by drying occupies the space in the drum during the cool-down operation, and the cold air fed into the drying chamber is inside the clothing in the drum. Is difficult to reach, and heat exchange efficiency is also poor, making it difficult to dissipate heat. Therefore, even if the temperature detected on the outlet side of the drying chamber is lowered to some extent, the temperature of the clothes on the inner side in the drum is not sufficiently lowered, and is particularly high when the initial temperature is high. The temperature may be maintained.

  In contrast, in the clothes dryer according to the first aspect of the invention, the higher the initial temperature, the longer the cool-down operation time. Therefore, the operation ends with the temperature of the inner clothes that are difficult to dissipate heat sufficiently reduced. be able to. Therefore, even if clothes are left in the drum after the operation is finished or if clothes taken out from the drum are left in a stacked state, the temperature of the stacked clothes is prevented from rising abnormally. can do. Thereby, even if fats and oils etc. remain in clothing, spontaneous ignition by oxidation heat storage can be avoided beforehand.

1 is a front plan view of a clothes dryer according to an embodiment of the present invention. The schematic longitudinal cross-sectional view which shows the internal structure of the principal part of an upper stage clothes dryer. The block block diagram of the control system of an upper stage clothes dryer. The flowchart which shows the control in the drying operation in the clothes dryer of a present Example. The flowchart which shows the control during the cool down driving | operation in the clothes dryer of a present Example. The flowchart which shows another control during the cool down driving | operation in the clothes dryer of a present Example. The flowchart which shows the control at the time of power activation in the clothes dryer of a present Example.

  An embodiment of a clothes dryer according to the present invention will be described with reference to the drawings. The clothes dryer according to the present embodiment is a two-stage clothes dryer in which clothes dryers having the same structure are stacked in two upper and lower stages in order to effectively use the installation space. Of course, the present invention can also be applied.

  FIG. 1 is a front plan view of the clothes dryer of this embodiment. In this clothes dryer, an upper clothes dryer 1 is arranged on a lower clothes dryer 2, and the housings 3 of both are integrated. Both clothes dryers 1 and 2 have large circular clothing input ports on the front surface of the housing 3, and each clothing input port can be opened and closed by a laterally opening type circular doors 4 and 5. A rotary power switch 6 for turning on and off the power is common to the upper and lower stages, and is provided in the lower left part of the front surface of the upper clothes dryer 1.

  Circuit boards equipped with control circuits and the like for independently controlling the operations of the upper and lower clothes dryers 1 and 2 are intensively disposed between the upper door 4 and the lower door 5. On the right edge, an operation panel is provided separately for upper and lower stages. The operation panel includes a start key 71 for instructing operation start (resumption of operation) as the operation unit 7, a time setting unit 72 for setting a drying operation time, and a temperature setting for setting an ultimate temperature during the drying operation. A unit 73 is provided, and a display unit 8 for displaying such set values and the remaining time during operation is arranged.

  The internal configuration of the upper garment dryer 1 and the lower garment dryer 2 is basically the same. FIG. 2 is a schematic longitudinal sectional view showing an internal configuration of a main part of the upper clothing dryer 1.

  A drying chamber 20 that is substantially sealed by the door 4 is formed inside the housing 3, and a drum 21 that has a cylindrical shape in the peripheral surface and a large number of ventilation holes is formed in the drying chamber 20. The main shaft 22 is installed so as to be rotatable. Opening / closing of the door 4 is detected by a door switch (corresponding to door opening / closing detection means in the present invention) 43 provided on the front side of the drum 21. The main shaft 22 is supported by a bearing 24 fixed to the partition wall 23 on the back surface of the drying chamber 20, and a large-diameter main pulley 25 is attached to the rear end of the main shaft 22 protruding rearward of the partition wall 23. . A drum motor (corresponding to the rotational driving means in the present invention) 26 is installed on the back of the drying chamber 20, and the rotational driving force of the drum motor 26 is transmitted to the main pulley 25 via a motor pulley 27 and a timing belt 28. Thus, the drum 21 is driven to rotate at a relatively low speed.

  An intake passage 31 is formed between the intake wall 30 and the intake port 30 opened on the back surface of the housing 3 in the upper part of the partition wall 23 on the back surface of the drying chamber 20. Gas (city gas or LP gas) is burned in the intake passage 31. A heating unit (corresponding to the heating means in the present invention) 32 for heating the air is provided. A drum inlet temperature sensor 33 for detecting the temperature of the hot air supplied into the drying chamber 20 is disposed between the heating unit 32 and the drying chamber 20 in the intake passage 31.

  On the other hand, the drying chamber 20 communicates with the ventilation chamber 36 through a vent 35 formed at the bottom thereof, and further communicates with an exhaust path 38 that communicates with an exhaust port 39 opened at the back of the housing 3 through a lint filter 37. is doing. A fan 41 that is rotationally driven by a fan motor 40 is provided in the exhaust passage 38 as a blowing means in the present invention. When the fan 41 is operated, outside air is sucked from the intake port 30 and supplied into the drying chamber 20. The air that has passed through the drying chamber 20 is exhausted from the exhaust port 39 to the outside through the ventilation chamber 36 and the exhaust passage 38. A drum outlet temperature sensor (corresponding to temperature detecting means in the present invention) 42 for detecting the temperature of the air (exhaust gas) discharged from the drying chamber 20 is disposed in the exhaust passage 38.

  If the heating unit 32 operates (gas combustion is performed) in a state where the air flow is generated, high-temperature air heated by the heating unit 32 is supplied into the drying chamber 20. Then, as indicated by arrows in FIG. 2, the hot air passes through the drum 21 in the drying chamber 20, and heat exchange is performed between the wet clothing housed in the drum 21 and the hot air. And the clothes are dried. Moist air containing water vapor from the clothing passes into the ventilation chamber 36, and foreign matters such as lint from the clothing when passing through the lint filter 37 are removed and finally discharged from the exhaust port 39 to the outside of the machine. The

  FIG. 3 is a block diagram of the control system of the clothes dryer 1 of the present embodiment. A control unit 50 (corresponding to the control means in the present invention) placed at the center of the control is configured around the CPU, and each of the start key 71, time setting unit 72, and temperature setting unit 73 provided on the operation unit 7 An instruction signal corresponding to the operation is input from the door switch 43, a door opening / closing detection signal, and a temperature detection signal from the drum inlet temperature sensor 33 and the drum outlet temperature sensor 42, respectively. Then, the control unit 50 sends a display control signal such as the remaining operation time to the display unit 8. The control unit 50 also controls the rotation of the drum motor 26 via the drum motor drive unit 51, controls the rotation of the fan motor 40 via the fan motor drive unit 52, and further heats the heating unit 32 via the heating drive unit 53. The igniter 321 for controlling the opening of the gas valve 322 for supplying gas to the gas burner and igniting the gas burner is driven. The control unit 50 is common to the upper garment dryer 1 and the lower garment dryer 2, and the other components are provided separately for the upper and lower stages.

  Further, the power switch 6 common to the upper and lower stages is connected to the power circuit 54, and even if the power is cut off by the operation of the power switch 6, the control unit 50 displays the operation state immediately before that in the flash memory (in the present invention). It has a function capable of supplying power for a short time so that the power is cut off after executing the control to write to the operation information storage means).

  In the clothes dryer of the present embodiment, the user sets the drying operation time with the time setting unit 72 of the operation unit 7 before the operation is started. Further, the temperature setting unit 73 sets the maximum temperature during the drying operation. This temperature setting is selected from four of 50 ° C., 60 ° C., 70 ° C., and 80 ° C. If the clothing to be dried is made of a fabric that is relatively resistant to heat, the temperature is set. In general, the temperature is reduced to prevent shrinkage and fabric damage, and in the case of a material that is resistant to heat such as cotton, the temperature is generally increased to increase the drying efficiency. When the user presses the start key 71 after making such settings, the drying operation is started. Further, after performing the drying operation for a set time, in order to lower the temperature of the clothes and make it easy for the user to take out, only the air is blown by the operation of the fan 41 and the clothes are stirred by the rotation of the drum 21 without heating. Perform cool-down operation.

  Next, control during the drying operation, which is one of the features of the clothes dryer according to the present embodiment, will be described with reference to the flowchart of FIG.

  When the drying operation is executed, the drum motor 26 is driven at a predetermined rotation speed under the control of the control unit 50, whereby the drum 21 is rotated at a low speed and the clothes inside are agitated. Further, the fan motor 40 is driven at a predetermined rotational speed, whereby the fan 41 rotates to generate the air flow as described above. Further, the heating drive unit 53 controls gas combustion in the heating unit 32, whereby the temperature of the air supplied to the drying chamber 20 is maintained substantially constant around a predetermined temperature (step S10). During the drying operation as described above, the control unit 50 monitors the door opening detection signal from the door switch 43 and repeatedly determines whether or not the door 4 has been opened (step S11).

  When the opening of the door 4 is detected, the control unit 50 stores the immediately preceding operation state (remaining operation time, etc.) in the flash memory (step S12), and the rotation of the drum 21 and the rotation of the fan 41 in order to temporarily stop the operation. All the heating by the heating unit 32 is stopped (step S13). Next, when it is detected that the door 4 is closed (Y in Step S14), the control unit 50 starts measuring time by a timer (Step S15), and whether or not a predetermined time Ta has elapsed since the time measurement started. Is repeatedly determined (step S16). Here, as an example, Ta is 4 minutes and 50 seconds.

  On the other hand, in parallel with the above steps S15 and S16, the control unit 50 repeatedly determines whether or not there is an instruction to restart operation by operating the start key 71 (step S21). Then, when it is detected that the start key 71 is operated, the remaining operation time is recognized by reading the data stored in the flash memory first, and drying is performed from the state immediately before the operation stop by opening the door 4 in step S11. Operation is resumed (step S22). If the process proceeds from step S21 to S22, execution of the processes in steps S15 to S20 is stopped at that time.

  When 4 minutes and 50 seconds elapse after the door 4 is closed and the operation is not instructed, the process proceeds from step S16 to S17. The drum motor 26 rotates the drum 21 in the right direction at a low speed and the fan motor 40 rotates the fan 41. Then, an air flow is passed through the drying chamber 20. At this time, since heating by the heating unit 32 is not performed, cold air having substantially the same temperature as the outside air temperature is fed into the drying chamber 20, and the clothes in the drum 21 are exposed to this cold air flow while being stirred. Then, it is repeatedly determined whether or not a predetermined time Tb has elapsed from the start of operation of the drum 21 and the fan 41 (step S18). Here, as an example, Tb is 10 seconds.

  If it is determined in step S18 that 10 seconds have passed without an instruction to start operation, the time count up to that point is reset (step S19), the drum 21 and the fan 41 are stopped (step S20), and step S15. Return to. Therefore, if there is no instruction to restart the operation from the time when the door 4 is once opened and closed, the operation stop period of 4 minutes and 50 seconds and the operation period of the drum 21 and the fan 41 for 10 seconds with one cycle of 5 minutes Is repeated (that is, intermittent operation is performed). Since the clothes stacked in the drum 21 do not move at all during the operation stop period, when the internal clothes contain oils and fats, there is a possibility that the heat given during the drying operation is stored and the temperature gradually increases. is there. However, during the operation for 10 seconds, the clothes stacked in the drum 21 are agitated and switched upside down, and the clothes receive a cold air flow to dissipate heat. Therefore, heat storage does not continue, and it can be avoided that the temperature of the internal garment becomes abnormally high and leads to spontaneous ignition.

  In addition, during the period when the rotation of the drum 21 is stopped (the period of 4 minutes and 50 seconds), the fan 41 may be operated for all or part of the period to blow air.

  Next, control during cool-down operation, which is another feature of the clothes dryer according to the present embodiment, will be described with reference to the flowchart of FIG. As described above, the cool-down operation is performed after the drying operation. When the cool-down operation is started, the control unit 50 stops the heating by the heating unit 32 and executes only the operation of the fan 41 by the fan motor 40 and the rotational driving of the drum 21 by the drum motor 26 (step S30). As a result, relatively uncooled air that is not heated is supplied into the drying chamber 20, and the clothes that are stirred by the rotation of the drum 21 are exposed to the cold air. Accordingly, the heat of the clothing that has been hot during the last drying operation is dissipated and the temperature gradually decreases.

  Thereafter, the controller 50 monitors the temperature detection signal from the drum outlet temperature sensor 42 and determines whether or not the drum outlet temperature is 50 ° C. or less (step S31). If the drum outlet temperature exceeds 50 ° C., the process returns to step S30, so that the cool-down operation is continued until the drum outlet temperature becomes 50 ° C. or less in steps S30 and S31. When the drum outlet temperature is lowered to 50 ° C. or lower, the controller 50 next determines whether or not the set temperature during the drying operation is 80 ° C. (step S32). It is determined whether or not there has been (step S34). N is determined in step S34 when the set temperature is 50 ° C.

  The temperature detected by the drum outlet temperature sensor 42 is the temperature of the air discharged from the drying chamber 20, but the temperature does not necessarily reflect the temperature of the clothes in the drum 21. That is, when the amount of clothes accommodated in the drum 21 is relatively large, particularly when an amount of clothes close to the rated capacity is accommodated, the drum 21 is occupied by clothes that are dry and swollen. Therefore, the cold air supplied to the drying chamber 20 is unlikely to pass through the clothes accommodated in the drum 21, so that even if the temperature of the clothes whose surface is in contact with the air is lowered, The temperature of the clothes may not be sufficiently lowered, and the temperature of the internal clothes may be higher as the set temperature during the drying operation is higher.

  Therefore, when the set temperature during the drying operation is the highest, 80 ° C. (Y in step S32), the control unit 50 controls each unit to further extend the cool-down operation for 5 minutes (step S33). If the set temperature during the drying operation is 60 ° C. or 70 ° C. (Y in step S34), the control unit 50 controls each unit to extend the cool-down operation for another 3 minutes (step S35). . When the set temperature during the drying operation is 50 ° C. (N in step S34), the control unit 50 further executes the cool-down operation for 5 seconds (step S36) and ends the operation.

  Thus, the higher the set temperature during the drying operation, the longer the duration of the cool-down operation after the drum outlet temperature becomes 50 ° C. or lower. Therefore, when the drum outlet temperature becomes 50 ° C. or lower, the internal temperature Even if the temperature of the clothes is not sufficiently lowered, the temperature of the clothes can be lowered and the operation can be terminated. As a result, even if clothes are left in the drum 21 after the cool-down operation is finished, or if clothes are taken out from the drum 21 and left in a stacked state, the temperature of the clothes inside becomes abnormally high. This can be prevented and spontaneous ignition due to the heat storage action can be avoided.

  Next, another control performed during the cool-down operation in parallel with the above control will be described with reference to the flowchart of FIG.

  During the execution of the cool-down operation as described above (step S40), the control unit 50 monitors the door open / close detection signal from the door switch 43 and repeatedly determines whether or not the door 4 has been opened (step S41). When the opening of the door 4 is detected, the control unit 50 stores the immediately previous operation state (remaining cool-down operation time, etc.) in the flash memory (step S42), and rotates the drum 21 and the fan 41 in order to temporarily stop the operation. Is stopped (step S43).

  Next, when it is detected that the door 4 is closed (Y in step S44), the control unit 50 automatically recognizes the remaining cool-down operation time by reading the data previously stored in the flash memory. Then, the cool-down operation is restarted from the state immediately before the operation stop by the opening of the door 4 in step S41 (step S45). Therefore, even if the user opens and closes the door 4 in the course of the cool-down operation and leaves it without performing any operation, the remaining cool-down operation is automatically executed, so that it is accommodated in the drum 21. It is possible to prevent the fire due to the heat storage action by lowering the temperature of the clothing.

  The above description is for the control when the door 4 is opened and closed during the cool-down operation. During the cool-down operation, the user operates the power switch 6 to turn off the power, and then operates the power switch 6. The same control can be performed even when the power is turned on. That is, when the power is turned off, the operation state immediately before the power is turned off is stored in the flash memory. This stored content is retained even when the power is turned off.When the power is turned on next time, if the flash memory data is read and it turns out that the cool-down operation is in progress, the remaining operation is continued. Can be started automatically as you do.

  Next, control when the user turns on the power by operating the power switch 6 in a state where the power is turned off will be described with reference to the flowchart of FIG.

  When the power is turned on by operating the power switch 6 (step S50), the control unit 50 first detects the drum outlet temperature from the temperature detection signal from the drum outlet temperature sensor 42, and whether or not the temperature is 51 ° C. or higher. Is determined (steps S51 and S52). Here, when the drum outlet temperature is 50 ° C. or less, it is determined that there is no clothing remaining in the drum 21 or that there is no problem such as ignition due to heat storage even if it remains. To do.

  On the other hand, when the drum outlet temperature is 51 ° C. or higher, it can be determined that there is a possibility that clothing whose temperature has not sufficiently decreased remains in the drum 21. Therefore, the control unit 50 performs the cool-down operation by performing the rotation driving of the drum 21 by the drum motor 26 and the operation of the fan 41 by the fan motor 40 (step S53). As a result, even when hot clothing remains in the drum 21, the temperature gradually decreases.

  If the drum outlet temperature becomes 50 ° C. or lower (step S54), after further cooling down operation for 5 seconds (step S55), this time, instead of continuous cooling down operation, intermittent drum 21 Then, the operation of the fan 41 is executed (step S56). Specifically, as in the processing of steps S15 to S20 shown in FIG. 4, every time the operation is stopped for a predetermined time Ta (for example, 4 minutes and 50 seconds), the operation is performed for a predetermined time Tb (for example, 10 seconds). What is necessary is just to perform control like this. The intermittent operation as described above may be continuously executed until the door 4 is opened (Y in step S57), and if the door 4 is opened, the drum 21 and the fan 41 may be stopped.

  As described above, in the clothes dryer according to the present embodiment, the temperature of the clothes inside the clothes in the state where the clothes stored in the drum 21 or the clothes taken out from the drum 21 are stacked by various controls as described above. Therefore, even if oils and fats remain in the clothing to be dried, spontaneous ignition due to oxidative heat storage can be prevented and high safety can be ensured.

  It should be noted that the above embodiment is merely an example, and it is obvious that any modification, correction, or addition as appropriate within the scope of the present invention is included in the scope of the claims of the present application.

DESCRIPTION OF SYMBOLS 1 ... Upper clothing dryer 2 ... Lower clothing dryer 3 ... Housing | casing 4, 5 ... Door 6 ... Power switch 7 ... Operation part 71 ... Start key 72 ... Time setting part 73 ... Temperature setting part 8 ... Display part 20 ... Drying Chamber 21 ... Drum 22 ... Main shaft 23 ... Partition wall 24 ... Bearing 25 ... Main pulley 26 ... Drum motor 27 ... Motor pulley 28 ... Timing belt 30 ... Intake port 31 ... Intake passage 32 ... Heating unit 321 ... Igniter 322 ... Gas valve 33 ... Drum inlet temperature sensor 35 ... vent 36 ... ventilation chamber 37 ... lint filter 38 ... exhaust path 39 ... exhaust port 40 ... fan motor 41 ... fan 42 ... drum outlet temperature sensor 43 ... door switch 50 ... controller 51 ... drum motor drive Unit 52 ... Fan motor drive unit 53 ... Heating drive unit 54 ... Power supply circuit

Claims (3)

A drum disposed in the drying chamber and containing the clothes to be dried;
Rotation driving means for rotating the drum;
A blowing means for supplying air to an air passage including the drying chamber;
Heating means for burning and heating air supplied into the drying chamber by the blowing means,
A cool-down operation for supplying air not heated by the heating means while rotating the drum, after performing a drying operation for supplying air heated by the heating means to the drying chamber while rotating the drum In the clothes dryer that performs
Temperature setting means for the user to set the temperature of the heated air supplied into the drying chamber during the drying operation;
Temperature detecting means for detecting the temperature of the air that has passed through the drying chamber;
The rotation driving means and the air blowing means so as to extend the cool-down operation for a time corresponding to the temperature set by the temperature setting means from when the temperature detected by the temperature detection means decreases to a predetermined value during the cool-down operation. Control means for controlling
A clothes dryer comprising:   2. The clothes dryer according to claim 1, wherein the unheated air is cold air having a temperature substantially the same as an outside air temperature outside the clothes dryer.   2. The clothes dryer according to claim 1, wherein the longer the temperature set by the temperature setting means, the longer the time during which the cool-down operation is performed.