JPH07289798A - Clothes dryer - Google Patents

Abstract

PURPOSE:To secure normal operation maintainance of a clothes dryer, despite undesirable external conditions, by means of stopping electricity to both of two heaters, when air temperature detected at an exit of a turning drum reaches above the upper limit of temperature, while another detected temperature that corresponds to room temperature being below a prescribed temperature. CONSTITUTION:During heating process, a microcomputor 50 electrifies heaters 18 to heat transmitted air, driving a motor 20 to rotate a turning drum and an air sending fan, and the drying operation is completed, when each temperature difference at the exit temperature sensor 29H and the ambient temperature sensor 33L reaches the prescribed value. In this instance, when the ambient temperature is below the prescribed temperature, while the exit temperature is above the prescribed temperature, only one of the heaters 18a, 18b, is to be electrified. When the exit temperature is below the prescribed temperature, both heaters 18a, 18b, are to be electrified. Further, when the ambient temperature is below the prescribed temperature, while the ambient temperature is above the upper limit, electricity is to be stopped to both the heater 18a and the heater 18b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clothes dryer for drying clothes contained in a rotating drum.

[0002]

2. Description of the Related Art Conventionally, there has been used a clothes dryer for supplying heated air to a rotating drum containing clothes and rotating the rotating drum to dry clothes. Such a clothes dryer is generally provided with a fan, and the air inside the clothes dryer is circulated by the rotation of the fan through a circulation duct connected to a rotating drum. A heating heater is attached near the inlet of the rotating drum. The heating heater heats the air sent in the circulation duct to generate heating air, and the generated heating air is supplied to the rotating drum. It In the rotating drum, heat is exchanged between the supplied heated air and the clothes, whereby the moisture impregnated in the clothes is evaporated. The moisture-containing air is exhausted from the rotary drum to the circulation duct. The exhausted hot and humid air is circulated again by the fan. At this time, by taking in the outside air from the outside air intake formed on the rear surface of the clothes dryer,
For example, if you cool the back of the fan, the hot and humid air exhausted from the rotating drum that hits the fan will be cooled,
The water contained in it is condensed. The dehumidified air is sent to the outlet side of the circulation duct by the rotation of the fan again. Condensed water is drained out of the dryer through a predetermined drainage port.

In this type of clothes dryer, the heater is generally ON / OFF-controlled in order to achieve good drying. An example of a clothes dryer that controls ON / OFF of a heater is disclosed in, for example, Japanese Patent Laid-Open No. 4-64339. In the prior art disclosed in this publication, two heating heaters composed of a positive temperature coefficient thermistor are used, and the drum outlet temperature detected by a temperature sensor provided near the outlet of the rotating drum and the heating heater Based on the heater inlet temperature detected by a temperature sensor provided on the upstream side, ON / OFF of the heating heater is performed.
OFF control is performed.

More specifically, the ON / OFF control of the heating heater is to keep the temperature of the clothes within a predetermined range after the temperature of the clothes contained in the rotating drum exceeds a reference temperature. Done. The temperature of the clothes accommodated in the rotary drum can be regarded as the same as the drum outlet temperature because heat is exchanged in the rotary drum. Therefore, in the ON / OFF control of the heating heater, when the drum outlet temperature is equal to or higher than a predetermined upper limit temperature, the drum outlet temperature is controlled to be low, and the drum outlet temperature is lower than the predetermined lower limit temperature. In this case, the drum outlet temperature is controlled to be high. The control for lowering the drum outlet temperature is performed by turning off the heater. That is, when the heating heater is turned off, the temperature of the heated air to be supplied to the rotary drum decreases, so the drum outlet temperature also decreases.

Here, the number of heaters to be turned off is
It depends on whether or not the heater inlet temperature is equal to or higher than a predetermined temperature. That is, when the heater inlet temperature is equal to or higher than the predetermined temperature and the drum outlet temperature is equal to or higher than the upper limit temperature, both heaters are turned off. On the other hand, when the heater inlet temperature is lower than the predetermined temperature and the drum outlet temperature is equal to or higher than the upper limit temperature, only one heater is turned off.

As described above, when only one heater is turned off when the heater inlet temperature is lower than the predetermined temperature, the drum outlet temperature can be sufficiently lowered without turning off both heaters. Because. More specifically, the heater inlet temperature is a value proportional to room temperature. That is, the case where the heater inlet temperature is lower than the predetermined temperature is the case where the room temperature is relatively low such as winter. Therefore, when the room temperature is relatively low, the drum outlet temperature can be sufficiently lowered by turning off only one of the heaters.

[0007]

However, in the above prior art, when the room temperature is relatively low, for example, the outside air for cooling cannot be taken in when the outside air intake is blocked by dust or the like. The air exhausted from the rotating drum cannot be cooled. As a result, the uncooled air is reheated by the one heater that is turned on, so that the temperature inside the rotary drum rises abnormally. Therefore, there is a problem that the subsequent operation cannot be performed normally.

Therefore, an object of the present invention is to solve the above-mentioned technical problems, and even when the room temperature is relatively low and the outside air intake is blocked by dust or the like, It is an object of the present invention to provide a clothes dryer that can perform a normal operation.

[0009]

In order to achieve the above object, a clothes dryer according to claim 1 comprises an air intake and an air outlet, a rotary drum for accommodating clothes, and an air of the rotary drum. One end is connected to the outlet, and the other end is connected to the air intake of the rotary drum. Circulating air passage means, and two heatings for generating heated air provided near the other end in the circulating air passage means. Means, and the heat exchange type air blowing means, the outer surface of which is exposed to the air entering and exiting from the outside air inlet / outlet, and the inner surface of which is provided with a fan for circulating the air in the circulation air passage means, First temperature detecting means for detecting the temperature of the air circulated by the exchange-type blowing means and exhausted from the exhaust outlet of the rotary drum, and second temperature detecting means for detecting the temperature proportional to room temperature. ,
When the temperature detected by the second temperature detecting means is lower than a predetermined temperature and the temperature detected by the first temperature detecting means is equal to or higher than a set temperature, only one of the two heating means is energized. When the temperature detected by the first temperature detecting means is lower than the set temperature, the energization control means for energizing both of the two heating means and the temperature detected by the first temperature detecting means are predetermined. And a determination means for determining whether or not the temperature has exceeded the upper limit temperature,
The energization control means determines that the temperature detected by the first temperature detection means is equal to or higher than the upper limit temperature by the determination means when the temperature detected by the second temperature detection means is lower than a predetermined temperature. And both of the above two heating means are prohibited from being energized.

Further, in the clothes dryer according to a second aspect of the present invention, the second temperature detecting means detects the temperature of the control board outside the circulation air passage means and made of a material having a large heat capacity. It is characterized in that it is provided at a position where the temperature can be controlled, and is for detecting the temperature of the control board.

[0011]

In the structure according to the above-mentioned claim 1, when the temperature detected by the second temperature detecting means is lower than the predetermined temperature and the temperature detected by the second temperature detecting means is equal to or higher than the set temperature, Only one of the two heating means is energized, and when the temperature detected by the second temperature detecting means is lower than the set temperature, both of the two heating means are energized.

When only one of the two heating means is energized, the temperature of the heated air to be supplied to the rotating drum is usually lower than when both are energized, so that the air outlet of the rotating drum is reduced. The temperature of the air exhausted from is relatively lowered. The temperature of the heated air to be supplied to the rotary drum becomes low because the hot and humid air exhausted from the air outlet of the rotary drum is cooled by the outside air and dehumidified.

Here, if the outside air intake is blocked by dust or the like, the outside air cannot be taken in. Then, the temperature of the air discharged from the rotating drum does not decrease, and the air whose temperature has not decreased is reheated by the one heating means that is energized. The temperature of the heated air to be supplied becomes abnormally high. Therefore, the temperature of the air exhausted from the rotary drum rises rather than decreases, so that the subsequent operation cannot be performed normally.

Therefore, in the present invention, a predetermined upper limit is set for the temperature of the air discharged from the rotary drum, and when the temperature of the air discharged from the rotary drum exceeds the above upper limit, two heating means are provided. It is supposed to prohibit both energization. Therefore, even if the outside air intake is blocked by dust or the like, the temperature of the air exhausted from the rotary drum can be lowered, and the subsequent operation can be performed normally.

According to the second aspect of the invention, the second
Since the temperature detecting means is provided outside the circulating air passage means, the influence of water and dust is less than that when it is provided inside the circulating air passage means. Therefore, it is possible to minimize the failure of the second temperature detecting means. Moreover, since the temperature of the control board with a large heat capacity is to be detected,
Even if the surrounding environment changes rapidly, the temperature can be detected stably.

[0016]

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a sectional view showing a schematic configuration of a clothes dryer according to an embodiment of the present invention. Dryer body 1
A drying chamber 2 is formed inside, and a rotating drum 3 for accommodating clothes is installed in the drying chamber 2. A door 4 is attached to the center of the front surface of the dryer main body 1 so as to be openable and closable, and clothes are thrown into the rotary drum 3 through the door 4.

The rotating drum 3 is rotatably supported by the dryer main body 1 via a felt or the like by a drum supporting plate 5 made of an annular metal plate, the front side of which is attached so as to surround the door 4, and the rear side thereof. It is rotatably supported on the dryer main body 1 by a shaft 6. An air intake 7 for taking in heated air, which will be described later, is formed in the lower portion of the front surface. Further, an air outlet 8 is formed near the center of the rear surface thereof, and this air outlet 8 is covered with a lint filter 9. Reference numeral 10 is a sealing member that seals between the drying chamber 2 and a fan chamber described later so that the air exhausted from the air outlet 8 does not enter the drying chamber 2.

At the rear of the rotary drum 3, a fan chamber 12 containing a heat exchange type double-sided fan 11 fixed to a shaft 6 is defined by a partially cut fan casing 13. The double-sided fan 11, which will be described in detail later, functions as the core of the heat exchange type blower for supplying the heated air generated by the heater to the rotary drum 3. The fan casing 13 is provided with a partition plate 14 made of synthetic resin so as to surround the double-sided fan 11. This partition plate 14
The double-sided fan 11 is housed in the central circular opening of the fan chamber 12, and the inner space of the fan chamber 12 is divided into the dry air passage 12a and the cooling air passage 12b. The cooling air passage 12b is
The fan casing 13 is connected to the drying chamber 2 at a cutout portion.

At the periphery of the double-sided fan 11, a dry air passage 12 is provided.
A concentric circular groove group 15 that opens toward a is integrally formed. The rotary groove group 15 is loosely fitted in the fixed groove group 16 formed integrally with the partition plate 14 in a non-contact state. That is, the rotary groove group 15 and the fixed groove group 16 form a labyrinth connection. Therefore, the dry air duct 12
Air cannot come and go between a and the cooling air passage 12b.

A circulation duct 17 is provided below the dryer main body 1.
Is provided. This circulation duct 17 is used for the dry air duct 1.
2a and the air intake 7 are connected, and a heater 18 that functions as a heating unit is disposed near the air intake 7. The heater 18 is composed of, for example, four honeycomb-shaped positive temperature coefficient thermistors. Condensed water, which will be described later, is fed to the lowest part of the circulation duct 8 by the dryer body
A drain port 19 for draining outside is formed. In this embodiment, the circulation duct 17 and the dry air duct 12 are
Circulating air duct means is constructed with a.

A motor 20 is provided at the bottom of the dryer main body 1. The motor 20 applies a rotational force to the belt 21 wound around the outer peripheral surface of the rotary drum 3 via the pulley 22 and a rotational force to the shaft 6 via the pulley 23 and the fan belt 24. As a result, the rotating drum 3
And the double-sided fan 11 is rotated. Above pulley 2
A rotation sensor 25 for detecting the number of rotations of the motor 20 is attached to the motor 3. The idler pulley 26 is for preventing the belt 21 from slipping by applying tension to the belt 21 when the rotary drum 3 rotates.

When the double-sided fan 11 rotates, air is sent from the drying air passage 12a to the circulation duct 17. The air sent to the circulation duct 17 is heated by the heater 18 to become heated air, which is taken into the rotary drum 3 from the air intake 7. In the rotating drum 3, heat exchange is performed between the heated air taken in and the clothes. As a result, the moisture contained in the clothes is evaporated. The air containing moisture is sent to the drying air passage 12a again by the rotation of the double-sided fan 11. That is, the rotation of the double-sided fan 11 causes the air to circulate through the dry air passage 12a, the circulation duct 17, and the rotary drum 3.

When the double-sided fan 11 rotates, the outside air is taken into the cooling air passage 12b from the outside air inlet 27 formed at the center of the rear surface of the dryer main body 1. At this time, the double-sided fan 11 is cooled by this outside air. The outside air taken in passes through the drying chamber 2 from the cooling air passage 12b and is discharged from the outside air outlet 28 formed in the lower part of the dryer main body 1. In addition,
In this embodiment, the double-sided fan 11 and the outside air intake 2 are
7 functions as a heat exchange type blower.

The air in the drying air passage 12a is a double-sided fan 11
It will be cooled when it comes into contact with. That is, since the double-sided fan 11 is cooled by the outside air, the air in the drying air passage 12a is cooled by coming into contact with the double-sided fan 11. Therefore, the moisture in the air exhausted from the rotary drum 3 is condensed. The dehumidified air is sent to the circulation duct 17 again by the rotation of the double-sided fan 11. The condensed water flows down through the dry air passage 12a and is drained from the drain port 19.

An outlet temperature sensor 29H for detecting the temperature of the air exhausted from the rotary drum 3 is arranged near the air outlet 8 of the rotary drum 3. Outlet temperature sensor 29
H is composed of a heat sensitive element such as a thermistor. A control plate 30 provided with various input keys and a display is provided below the front surface of the dryer main body 1. Inside the drying chamber 2 below the control plate 30 and below the dryer main body 1, a substrate case 31 made of synthetic resin is attached with screws 32. The board case 31 is internally provided with a control board (not shown) formed of a member having a large heat capacity that is not easily affected by a sudden change in ambient temperature. On the control board,
A microcomputer described later and an atmosphere temperature sensor 33L for detecting the substrate temperature of the control substrate are mounted. The ambient temperature sensor 33L is also composed of a heat sensitive element such as a thermistor.

FIG. 2 is a front view in which a part of the control plate 30 is omitted. The control plate 30 has a power switch (S) for turning on the power.
W) 40, a start / pause switch (SW) 41 for starting or temporarily stopping the drying operation, and a course selection switch 42 for selecting a drying course such as “standard course” or “slightly dry”. There is. Further, the control plate 30 includes a heater changeover switch 4 for selecting the degree of heating of the air in the heater 18.
3, LED indicator 4 to inform the user of the drying process
4, and a sign indicator 45 for notifying the user of clogging of the lint filter 9 is provided.

FIG. 3 is a block diagram showing the electrical construction of the clothes dryer. The clothes dryer is provided with a microcomputer 50 for controlling the operation of each part of the clothes dryer. This microcomputer 5
Reference numeral 0 includes a CPU, a ROM, a RAM, and a timer, which are not shown, and performs a predetermined control according to a program stored in the ROM. In this embodiment, the microcomputer 50 functions as an energization control unit, a determination unit, and the like.

The microcomputer 50 includes a rotation speed detection circuit 51 including a rotation sensor 25 and a power switch 4.
An input key circuit 52 including 0, a door switch 53 for detecting opening / closing of the door 4, an LED lighting circuit 54 including an LED indicator 44, a reset circuit 55 including a start / pause switch 41, and a clock for generating a clock. The oscillation circuit 56 is connected.

Further, the microcomputer 50 is connected with a power supply circuit 57 connected to a commercial power supply, a power supply voltage determination circuit 58 for determining the voltage of the power supply circuit 57, and a buzzer for notifying the completion of the drying operation and the like. Buzzer circuit 59,
And a commercial power source zero-cross signal detection circuit 60 for detecting the zero-cross of the commercial power source is connected. Further, the microcomputer 50 has an outlet temperature sensor 29H,
The ambient temperature sensor 33L, the motor 20, the heater 18 including the first heater 18a and the second heater 18b, and the automatic power for automatically shutting off the power supply to the clothes dryer after the drying operation is completed. Off (A
A load driving circuit 62 for driving the PO) 61 is connected. Each of the first heater 18a and the second heater 18b is formed by forming two positive temperature coefficient thermistors in a honeycomb shape, and when "weak" is selected by the heater changeover switch 43, only one of them is selected. Both are energized when "strong" is selected.

FIG. 4 is a graph showing changes in the outlet temperature T1 detected by the outlet temperature sensor 29H and the substrate temperature T2 detected by the ambient temperature sensor 33L with respect to the operating time t in this embodiment. The outlet temperature T1 changes like a curve L1. That is, in the preheating period I, the amount of heat applied is spent to raise the temperature of the dryer body 1 and the clothes themselves containing a large amount of water, so that the outlet temperature T1 gradually rises, and in the constant rate drying period II, Since most of the applied heat amount is spent for evaporating the moisture in the clothes, the outlet temperature T1 becomes almost constant. Further, in the rate-decreasing drying period III, the amount of heat applied is consumed not only for the evaporation of water but also for the temperature rise of the clothes itself with reduced water content or the dryer main body 1, so the outlet temperature T1 rises again. I will do it.

During the rate-decrease drying period III, the outlet temperature T1 is set to a predetermined upper limit temperature T _max (for example, T _max = 84).
Lowered after reaching ° C.), outlet temperature T1 rises again when reduced to a predetermined lower limit temperature T _{mi n} (e.g. T _min = 82 ° C.), and so on, the outlet temperature T1 is the predetermined range T
_The reason for reciprocating between _mm (T _mm = 2 ° C. in the above example) is because ON / OFF control of the heating heater 18 described later is performed. The ON / OFF control of the heater 18 is performed to achieve good drying.

On the other hand, the substrate temperature T2 is the curve L2
It changes like. That is, it rises very slowly at first, and after some time elapses (for example, 60
Min), it will remain stable. 5, 6, and 7, the heating heater 18 is turned on for the drying process in the clothes dryer.
It is a flow chart for explaining focusing on / OFF control.

As shown in FIG. 5, when a user puts clothes into the rotary drum 3 and turns on the power switch 40 and the start / stop switch 41 (step S1), first, various flags are initialized. It That is,
A temperature down flag DF indicating whether the outlet temperature T1 is higher or lower than the predetermined range T _mm and a heater strong flag HF indicating whether or not both the heaters 18 should be turned on are reset (steps S2 and S3). . After that, as will be described later in detail, the time to be counted by the counter for counting the time until both the heaters 18 are turned on is set to a predetermined time (for example, 2 minutes) (step S4).

Next, a process of acquiring various data required for ON / OFF control of the heater 18 is performed (step S5). The details of this data acquisition process will be described later. Then, the motor 20 is turned on (step S
6). When the motor 20 is turned on, the driving force is applied to the rotary drum 3 and the double-sided fan 11 accordingly,
The rotary drum 3 and the double-sided fan 11 rotate. Then, ON / OFF control of the heater 18 is performed based on the various data acquired in step S5 (step S7). The details of this ON / OFF control process will also be described later. Then, after other control necessary for drying is performed (step S8), it is determined whether or not the drying process is completed (step S9).

The drying process is performed by, for example, the outlet temperature sensor 29.
H and the temperature difference T (T = | T) between the outlet temperature T1 and the substrate temperature T2 detected by the ambient temperature sensor 33L, respectively.
1-T2 |) reaches a preset predetermined temperature difference T _th1 (for example, T _th1 = 10 deg) or when a separately designated time has elapsed from the time when the drying process was started. It

When it is determined that the drying process is not completed as a result of the determination in step S9, the above step S2 is performed.
~ The processing up to step S8 is repeated. On the other hand, if it is determined that the drying process has been completed, the cool down process is performed for the purpose of cooling the clothes that have become hot due to the drying process so that the user can easily take them out (step S10). This cool-down process is performed by turning off the heater 18, and when the outlet temperature T1 detected by the outlet temperature sensor 29H reaches a predetermined temperature difference T _th2 (for example, T _th2 = 40 ° C.), or a predetermined temperature difference. It ends when the cooldown time elapses.

After the completion of this cool down process, the motor 20 is turned off and the entire drying process is completed. FIG. 6 is a flow chart for explaining the data acquisition process of step S5. In the following description, FIG.
See also In this data acquisition process, first, the substrate temperature T2 detected by the ambient temperature sensor 33L is the reference temperature T.
It is determined whether or not it is ₀ (for example, T ₀ = 40 ° C.) or more (step S11). The substrate temperature T2 is a temperature substantially proportional to room temperature. That is, in this step S11,
The room temperature is determined. The purpose of determining whether the room temperature is high or low is to make the number of the heaters 18 to be turned off different depending on the room temperature, as described later.

When the substrate temperature T2 is determined to be the reference temperature T ₀ or higher as a result of the determination in step S11, the reference temperature flag KF indicating that the substrate temperature T2 is the reference temperature T ₀ or higher is set. (Step S12) If it is determined that the substrate temperature T2 is lower than the reference temperature T ₀ , the reference temperature flag KF is reset (step S1).
3).

Next, the outlet temperature T1 detected by the outlet temperature sensor 29H is an abnormal temperature T ₁ (for example, T ₁ = 88 ° C.).
It is determined whether or not the above is true (step S14). The abnormal temperature T ₁ means the clothes contained in the rotary drum 3 and the rotary drum 3 when the outlet temperature T1 rises further.
It is the temperature at which it is determined that the clothes will be abnormally heated and the subsequent operations in the clothes dryer cannot be performed normally.

The result of the discrimination at the step S14, when the outlet temperature T1 is determined to be abnormal temperature above T _1, is abnormal temperature flag EF is set to indicate that the outlet temperature T1 is abnormal temperature above T ₁ (Step S15) If it is determined that the outlet temperature T1 is lower than the abnormal temperature T ₁ , then the abnormal temperature flag EF is reset (step S1).
6).

The outlet temperature T1 may exceed the abnormal temperature T ₁ only during the rate-decreasing drying period III (see FIG. 4). Next, it is determined whether or not the temperature down flag DF is set (step S17). As a result, if it is determined that the temperature down flag DF is not set, then it is determined whether the outlet temperature T1 is _lower than the upper limit temperature T _max (step S18), and the outlet temperature T1 is the upper limit temperature T _max. Only when the above is reached, the temperature down flag DF is set (step S19). On the other hand, if it is determined that the temperature down flag DF is set, then it is determined whether or not the outlet temperature T1 is _{equal to} or higher than the lower limit temperature T _min (step S20), and the outlet temperature T1.
The temperature down flag DF is reset only when is lower than the lower limit temperature T _min (step S21).

More specifically, referring to FIG.
During the period, the temperature down flag DF remains reset (since it is reset in advance in step S2). Then, when the outlet temperature T1 becomes _{equal to} or higher than the upper limit temperature T _max , the temperature down flag DF is set, and this state continues for a while. And the outlet temperature T1
When becomes, the temperature becomes less than the lower limit temperature T _min , so the temperature down flag DF is reset.

After the processing of steps S17 to S21 is finished, if the time to be counted by the counter is set, the counting of the counter is started (step S22). For example, immediately after the start of the drying process, the predetermined time (2 minutes in the above example) has been set in step S4, so counting is started. After such counting is completed (step S23), the heater strong flag HF is set (step S24).

FIG. 7 shows the heater 1 in step S6.
8 is a flowchart for explaining ON / OFF control of No. 8 of FIG. Also in the explanation of this ON / OFF control, FIG. 4 is referred to. In the ON / OFF control of the heater 18, first, it is determined whether or not the temperature down flag DF is set (step S25). As a result, when it is determined that the temperature down flag DF is not set, it is determined whether or not the heater strong flag HF is set (step S26). As a result, when it is determined that the heaters are set, the first and second heaters 18
Both a and 18b are turned on (step S27).
On the other hand, if it is determined that the heaters have not been set, then one of the first and second heaters 18a and 18b is turned on and the other is turned off (step S28).

The above process will be described more specifically. The temperature down flag DF and the heater strong flag HF are reset immediately after the start of the drying process and before the count of the counter is completed. Therefore, only one of the first and second heaters 18a and 18b is turned on. After the count of the counter is completed, the temperature down flag DF and the heater strong flag HF are kept until the outlet temperature T1 becomes equal to or higher than the upper limit temperature T _max.
Are reset and set respectively, so the first
Also, both the second heaters 18a and 18b are turned on.

On the other hand, if it is determined in step S25 that the temperature down flag DF is set, it is determined whether the outlet temperature T1 has reached the abnormal temperature T ₁ (step S29). ). As a result, when it is determined that the outlet temperature T1 has reached the abnormal temperature T ₁ , both the first and second heaters 18a and 18b are turned off (step S33). That is, regardless of whether the substrate temperature T2 is high or low, that is, whether the room temperature is high or low, when the outlet temperature T1 becomes equal to or higher than the abnormal temperature T ₁ , both the first and second heaters 18a and 18b are turned off. This allows
Since the temperature of the heated air to be supplied to the rotary drum 3 can be greatly reduced, the outlet temperature T1 is lowered. That is, as shown in FIG. 4, after the outlet temperature T1 becomes, it decreases as in the period of.

The first and second heaters 18 are also provided.
Prior to turning off a and 18b, the heater strong flag HF is reset (step S31), and a predetermined time (for example, 1 minute) is set in the counter (step S32). The predetermined time to be set is sufficiently longer than the time required for the outlet temperature T1 to be in the state shown in FIG. This is to prevent the heating heaters 18a, 18b from being overloaded by suddenly turning on both the first and second heating heaters 18a, 18b. That is, since the heater strong flag HF is reset while the counter is counting, the first or second heater 18a,
Only one of 18b is turned on. Therefore, the load on the heater 18 can be minimized.

On the other hand, as a result of the determination in step S29, if it is determined that the outlet temperature T1 is not higher than the abnormal temperature T ₁ , it is determined whether or not the reference temperature flag KF is set (step S30). . Next, the purpose of this determination will be described. That is, the temperature down flag DF
Is set when it is determined that the outlet temperature T1 is _{equal to} or higher than the upper limit temperature T _max. Therefore, when the temperature down flag DF is set, ON / OF of the heater 18 is turned on.
In the F control, the heater 18 is turned off because the outlet temperature T1 is lowered. However, when the room temperature is low, both of the heaters 18 to be turned off are normally turned off.
Even if it does not, the outlet temperature T1 is sufficiently lowered. Therefore, in step S30, it is determined whether the room temperature is high or low.

If it is determined that the reference temperature flag KF is set as a result of the determination in step S30, it is determined that the room temperature is relatively high, and therefore the heating degree of the air in the heater 18 is determined. In order to lower the temperature, the heater strong flag HF is reset (step S31), and after a predetermined time is set in the counter (step S32),
Both the first and second heaters 18a and 18b are O
FF is performed (step S33). On the other hand, if it is determined that the reference temperature flag KF is not set, it is determined that the room temperature is relatively low, so either one of the first and second heating heaters 18a and 18b is turned on and the other one is turned on. Is turned off (step S28).

When the outside air inlet 27 is blocked by dust or the like, the outlet temperature T1 does not decrease but rises even if only one heater 18 is turned off. However,
When the outlet temperature T1 becomes to continue abnormal temperature above T ₁ increases, the first and second by the discrimination at step S28
Since both the heaters 18a and 18b are turned off,
The outlet temperature T1 surely decreases. Therefore, the subsequent operation can be performed normally, and good drying can be realized.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments. For example, in the above-described embodiment, the ambient temperature sensor 33L mounted on the control board has been described as an example of the second temperature detecting means, but the second temperature detecting means detects the temperature near the inlet of the heater 18. Temperature sensor for detecting the room temperature or a room temperature sensor for directly detecting the room temperature, and any other sensor that detects a temperature proportional to the room temperature can be applied. When the temperature near the inlet of the heater 18 is detected, the reference temperature T ₀ is 50.
° C. is preferred, and when detecting room temperature directly, 30 ° C. The above-mentioned reference temperature T ₀ is preferable.

In the above embodiment, the case where the positive temperature coefficient thermistor is used as the heating means has been described, but for example, a gas heater or other heating element can be applied as the heating means. Other various design changes can be made without changing the gist of the present invention.

[0053]

As described above, according to the clothes dryer of the present invention, when the temperature detected by the second temperature detecting means is lower than the predetermined temperature, the temperature detected by the first temperature detecting means by the determining means. If it is determined that the temperature exceeds the predetermined upper limit temperature, both of the two heating means are prohibited from being energized. Therefore, the temperature of the air exhausted from the rotary drum decreases, and the subsequent operation can be performed normally. Therefore, good drying can be realized.

In particular, according to the clothes dryer of the second aspect, the second temperature detecting means is provided outside the circulation air passage means, so that water and dust are compared with the case where the second temperature detection means is provided inside the circulation air passage means. Is less affected by. Therefore, the failure can be minimized. Moreover, since the temperature of the control board having a large heat capacity is detected, the temperature can be detected stably even if the surrounding environment changes rapidly.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a schematic configuration of a clothes dryer according to an embodiment of the present invention.

FIG. 2 is a front view in which a part of a control plate constituting a part of the clothes dryer is omitted.

FIG. 3 is a block diagram showing an electrical configuration of the clothes dryer.

FIG. 4 is a diagram showing a time change of each temperature detected by two temperature sensors forming a part of the clothes dryer.

FIG. 5 is a flowchart for explaining a drying process of the clothes dryer.

FIG. 6 is a flow chart for explaining a drying process of the clothes dryer.

FIG. 7 is a flow chart for explaining a drying process of the clothes dryer.

[Explanation of symbols]

 1 Dryer Main Body 3 Rotating Drum 11 Double-sided Fan 12a Drying Air Path 17 Circulation Duct 18 Heating Heater 29H Outlet Temperature Sensor 33L Atmosphere Temperature Sensor 50 Microcomputer

Claims (2)

[Claims] 1. A rotating drum having an air intake and an air outlet for accommodating clothes, one end of which is connected to the air outlet of the rotating drum, and the other end of which is connected to the air intake of the rotating drum. The air passage means, the two heating means provided in the vicinity of the other end in the circulation air passage means for generating heated air, and the outer surface thereof is exposed to the outside air entering and exiting from the outside air inlet / outlet,
On its inner surface, there is provided a heat exchange type air blowing means provided with a fan for circulating the air in the circulation air passage means, and by the heat exchange type air blowing means, the air is circulated and exhausted from the air outlet of the rotary drum. A first temperature detecting means for detecting the temperature of the air, a second temperature detecting means for detecting a temperature proportional to room temperature, and a temperature detected by the second temperature detecting means is lower than a predetermined temperature. In above, when the temperature detected by the first temperature detecting means is equal to or higher than the set temperature, only one of the two heating means is energized, and the temperature detected by the first temperature detecting means is less than the set temperature. In some cases, an energization control unit that energizes both of the two heating units and a determination unit that determines whether or not the temperature detected by the first temperature detection unit is equal to or higher than a predetermined upper limit temperature. The energization control means may include, when the temperature detected by the second temperature detection means is lower than a predetermined temperature, the temperature detected by the first temperature detection means by the determination means is equal to or higher than the upper limit temperature. If it is determined that the above, it is forbidden to energize both of the above two heating means, a clothes dryer. 2. The second temperature detecting means is provided outside the circulation air passage means and at a position capable of detecting the temperature of a control board made of a material having a large heat capacity.
The clothes dryer according to claim 1, which is for detecting the temperature of the control board.