JP3109289B2 - 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 for circulating warm air into a rotating drum driven by a motor to dry clothes.

[0002]

2. Description of the Related Art In recent years, household clothes dryers are provided with a filter for removing lint and the like in a rotating drum for drying clothes, and when the lint of the filter is increased and clogged, an indicator light is used. Clothes dryers that report clogging have been proposed.

Conventionally, this type of clothes dryer has been disclosed in
No. 16631. That is, a current change of a positive characteristic temperature-sensitive resistance heater (hereinafter, referred to as a PTC heater) is detected by a current transformer, and if the detected PTC heater current is smaller than a set value, clogging is notified.

[0004]

In such a conventional clothes dryer, the PTC heater current varies depending on the intake air temperature, air volume, and voltage. Since the current change of the heater is much larger than the current change due to clogging, it is almost impossible to find a set value that can detect clogging only by the current change in consideration of all fluctuations. There is a problem that it is impossible to detect a clogged state.

[0005] The present invention solves the above-mentioned conventional problems.
It is an object of the present invention to provide a clothes dryer capable of detecting clogging without being affected by a temperature change or a voltage change.

[0006]

In order to achieve the above object, the present invention provides a rotating drum for drying clothes, a blowing means for circulating warm air into the rotating drum, and a blowing path into the rotating drum. PTC heater (Positive temperature sensing resistor)
An anti-heater) , a filter provided in the blowing path, a motor for rotating the blowing means or the rotating drum, a rotation detecting means for detecting the number of rotations or a rotating cycle of the rotating drum, the motor, and the like, and the motor Control means for controlling the rotation speed of the PTC or the PTC heater;
A temperature detecting unit provided in a blowing path to the heater; a current detecting unit connected to the control unit for detecting a current of the PTC heater; and a notifying unit, wherein the control unit keeps the rotation speed of the motor constant. The first problem solving means is that the clogging of the filter is notified by the output signal of the temperature detecting means and the output signal of the current detecting means.

Further, the control means of the first means for solving the problems sets the rotation speed of the rotating drum or the motor to a lower rotation speed than the normal rotation speed during the drying operation, and outputs the output signal of the temperature detection means and the current detection means. The second problem solving means is to notify the clogging of the filter by the output signal.

Further, the control means of the first means for solving the above problems sets the rotating speed of the rotating drum or the motor to a substantially minimum rotating speed at the time of starting the operation and then increases the rotating speed to the normal rotating speed. The third problem-solving means is to set the rotation speed to a low speed and to notify the clogging of the filter by the output signal of the temperature detecting means and the output signal of the current detecting means.

Further, the control means of the first means for solving the problem sets the rotation signal of the rotating drum or the motor to a lower speed than the normal speed for a certain period during the drying operation, and then outputs the output signal of the temperature detecting means and the current. A fourth problem solving means is to notify the clogging of the filter by the output signal of the detecting means.

[0010]

According to the first aspect of the present invention, there is provided:
The clogging of the filter can be detected based on the intake air temperature of the PTC heater and the power applied to the PTC heater, and the clogging can be accurately detected regardless of a voltage change or a temperature change.

According to the second means for solving the problems, the voltage,
Even when the amount of the material to be dried changes, the number of rotations for detecting filter clogging can be reliably controlled to be constant, and clogging detection accuracy can be improved.

Further, according to the third means for solving the problems, the PTC
Starting with the heater current reduced, there is no interruption of the power supply breaker due to the inrush current of the PTC heater, and clogging of the filter can be detected at the initial stage of starting the operation, so that the user can be reliably informed. .

Further, by operating at a low rotation speed for a certain period of time, the temperature inside the rotating drum can be made substantially constant, and the accuracy of clogging detection can be improved.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS.

As shown in FIG. 1, the rotary drum 1 is for storing and drying the object to be dried (clothing), and circulates warm air through the rotary drum 1 by a heat exchange type double-wing fan (blower means) 2. The heat exchange type double-wing fan 2 circulates warm air in the rotating drum 1 and simultaneously takes in air from the outside to cool the fan and dehumidifies the circulating air in the rotating drum 1. P
The TC heater (heating means) 3 is disposed in a blowing path to the rotary drum 1, that is, in a circulating air intake, and heats circulating air. The filter 4 is provided in a blowing path of the heat exchange type double-wing fan 2, that is, an air outlet of the air in the rotating drum 1. If the filter 4 is clogged by lint or the like, the amount of air to be blown is reduced, the heating power of the PTC heater 3 is reduced, and the drying time is prolonged and the drying efficiency is reduced. The motor 5 drives the rotary drum 1 and the heat exchange type double-blade fan 2 to rotate. By controlling the rotation speed of the motor 5, the rotation speed of the rotary drum 1 and the heat exchange type double-blade fan 2 can be controlled.
The amount of heat generated by the heater 3 can be controlled, and current control can be performed. The temperature detecting means 6 detects the temperature of the intake air of the PTC heater 3.

The rotation detecting means 7 detects the number of rotations of the rotating drum 1, and attaches a magnet 8 to the rotating drum 1 to 3-6.
The magnetic sensor (not shown) is fixed to the main body, and the rotation speed of the rotating drum 1 is detected. The control means 9 controls the number of rotations of the motor 5 and the PTC heater 3, and controls the number of rotations of the rotating drum 1, the output of the rotation detecting means 7 and the output of the number of rotations setting means 10. A rotational speed comparing means 11 to be compared, and a bidirectional thyristor 1 connected in series to the motor 5 by an output of the rotational speed comparing means 11
A conduction angle control means 13 for controlling the conduction angle of the motor 2 and the motor 5
Low-speed starting means 14 for lowering the set number of revolutions when starting
A temperature control means 15 and a clogging detection level setting means 16 for inputting an output of the temperature detecting means 6; Consists of

The difference between the rotation speed of the rotary drum 1 detected by the rotation detection means 7 and the set rotation speed from the rotation speed setting means 10 is compared by the rotation speed comparison means 11, and the conduction angle control means 13 controls the bidirectional thyristor. 12 to control the motor 5
To control the number of revolutions. Phase control is considered as the simplest conduction time control method. In the case of an inverter, not only the conduction time but also the frequency is controlled. In this way, stable rotation control of the motor 5 and the rotating drum 1 can be performed. Further, the output of the temperature detecting means 6 for detecting the temperature of the circulating air of the rotating drum 1 is input to the temperature control means 15, and the relay contacts 19a, 19b connected to the PTC heaters 3a, 3b respectively by the output of the temperature control means 15. Control the PT
The C heaters 3a and 3b are turned on and off to control the temperature of the circulating air. Further, the output of the clogging detection level setting means for inputting the output of the temperature detection means 6 and the current detection means 1
7 is input to the notification determining means 18 and the notification means 2
0 indicates that the filter 4 is clogged. The operation setting means 21 is connected to the control means 9 to set and operate a plurality of types of operation courses. The operation setting means 21 can be inputted to the rotation number setting means 10 to set the rotation number of the rotary drum 1 to a rotation number corresponding to the operation course. In addition, the temperature in the rotating drum 1 is controlled according to the operation course by inputting to the temperature control means 15 and according to the output of the temperature detecting means 6.

The current detecting means 17 comprises a current transformer 2
2 and a current-voltage conversion circuit 23, which detects the input current of the PTC heater 3 and outputs the output to the current setting comparing means 2
Enter 4 The current comparison setting unit 24 compares the set current value of the PTC heater 3 with the output of the current detection unit 17,
The output is input to the rotation speed setting means 10 to control the set rotation speed. Here, the set rotation speed set by the rotation speed setting means 10 is set such that the current of the PTC heater 3 does not become equal to or more than a predetermined current value.
The output of the current detecting means 17 is input to the clogging notification determining means 18 together with the output of the clogging detection level setting means 16 for calculating the clogging detection level based on the output of the temperature detecting means 6, and the rotation speed of the motor 5 is determined. In a state where the filter 4 is set to be constant, the output of the clogging detection level setting unit 17 and the output of the current detecting unit 17 are compared, and the notifying unit 20 notifies the clogging of the filter 4. That is, by controlling the rotation of the heat exchange type double-blade fan 2, the blowing condition at the time of detecting the clogging is set to be constant.

The operation of the above configuration will be described with reference to FIGS. 3 to 6. First, FIG. 3 shows the characteristics of the input power P of the PTC heater 3 and the intake air temperature T for showing the method of detecting clogging according to the present invention. FIG. 3 is a diagram showing an input electric power P of the PTC heater 3 as a temperature difference ΔT between the Curie temperature Tq and the intake air temperature T.
P = H (Tq-T). When the filter 4 is clogged, the heat radiation coefficient H decreases due to a decrease in the air flow due to the clogging. Therefore, since the Curie temperature Tq is constant, the heat radiation coefficient H can be obtained from the input power P and the intake air temperature T. Can be estimated. A in FIG. 3 indicates PTC when there is little clothing.
The relationship between the input current I of the heater 3 and the intake air temperature T is shown, where A 'shows the characteristics when there are many clothes, and B shows the characteristics when the filter is clogged. C indicates a clogging detection level of the input current I of the PTC heater 3 with respect to the intake air temperature T for determining clogging. The detection level Is can be set substantially linearly in accordance with the intake air temperature T, such as Is = K-kT. Here, K and k are constants.

Next, the detection of clogging is performed by controlling the number of rotations of the rotary drum 1, in other words, the number of rotations of the motor 5 to a constant value. That is, as shown in FIG. 4, at time t0, the low-speed starting means 14 changes the rotation speed set by the rotation speed setting means 10 to the low rotation speed n1 (the rotation speed 4 of the rotating drum 1 during normal operation).
For example, 36 rpm is set for 5 rpm, and the process is started. Then, at t1 after a predetermined time (for example, 20 seconds) has elapsed, the set number of revolutions is calculated by the number of revolution setting means 10 according to the temperature detected by the temperature detecting means 6, and the number of revolutions of the motor 5 is calculated based on the set number of revolutions. Control and
Gradually increase the speed. After maintaining the rotation speed constant for a predetermined time (for example, 1 minute) from time t2 when the rotation speed n2 is lower than the normal rotation speed n3 to time t3, clogging is detected at time t3, and then the rotation speed is reduced. The operation is gradually increased and the engine is operated at a normal rotation speed n3 from time t4.

Next, the operation will be described in detail with reference to FIG. 5. The operation is started in step 30, the initial setting is performed by the operation setting means 21 in step 31, and the soft start is performed in step 32. That is, the low-speed starting means 14 sets the rotational speed set by the rotational speed setting means 10 to the low-speed rotational speed n1, and starts. Then, in step 33, the temperature is detected by the temperature detecting means 6 to control the temperature.
It is determined whether the PTC heater 3 is turned on based on the temperature detected in step 4. Next, in step 35, the current of the PTC heater 3 is detected by the current detecting means 17 and input to the rotational speed setting means 10 through the current comparing and setting means 24. In step 36, the set rotational speed is calculated. Based on the rotation speed, the rotation speed of the motor 5 is controlled in step 37, and the process proceeds to step 40 via steps 38 and 39 to determine the rotation speed of the rotating drum 1. When the rotation speed n of the rotating drum 1 becomes n ≧ n2 in step 40, the process proceeds to step 41, where clogging is detected.

The clogging detection operation will be described with reference to FIG. 6. In step 50, a clogging detection subroutine is started, and in step 51, the rotational speed of the rotary drum 1 is set to n.
Control to 2 constant. After a delay of a predetermined time (for example, one minute) in step 52, in step 53
To detect the temperature of the circulating air. Next, step 5
In step 4, the clogging detection level setting means 15 calculates the detection level Is shown in FIG. Then, step 55
Then, the current I of the PTC heater 3 is detected by the current detecting means 17, and the detection level Is is compared with the current I in step 56. If the filter 4 is clogged, the amount of circulating air decreases, and if I <Is, step 57
Then, an output is output from the clogging notification determining means 18 and the clogging is notified by the notifying means 20. And step 5
At step 8, the clogging detection flag is turned on, the process proceeds to step 59, and returns to step 33 of FIG.

Thereafter, since the detection of clogging has been completed, steps 33 to 39 in FIG. 5 are repeated to dry the material to be dried in the rotary drum 1. If it is determined in step 38 that the drying has been completed, the flow proceeds to step 42. Proceed and end all operations.

As described above, according to this embodiment, the rotation speed of the rotary drum 1 is set to a substantially minimum rotation speed at the time of starting the operation, and then the rotation speed is lowered to the normal rotation speed during the operation of raising the rotation speed to the normal rotation speed. After a certain period of time is set, the clogging of the filter 4 is notified by the output signal of the temperature detecting means 6 and the output signal of the current detecting means 17, so that the filter is not affected by temperature change or voltage change. Clogging can be detected and detection accuracy can be improved.

[0025]

As is apparent from the above embodiments, according to the present invention, a rotating drum for drying clothes, a blowing means for circulating warm air into the rotating drum, and a blowing path to the rotating drum PTC heater provided in the, a filter provided in the blowing path, a motor for rotating the blowing means or the rotating drum, a rotation detecting means for detecting the number of rotations or rotation cycle of the rotating drum, motor, etc., Control means for controlling the number of revolutions of the motor or the PTC heater; temperature detecting means provided in a ventilation path to the PTC heater; and the PTC connected to the control means.
Current detection means for detecting the current of the heater, and notification means, the control means sets the number of rotations of the motor to a constant, the output signal of the temperature detection means and the output signal of the current detection means Since the clogging of the filter is reported, the clogging of the filter can be detected based on the intake air temperature of the PTC heater and the electric power applied to the PTC heater, and the clogging can be accurately detected regardless of the voltage change and the temperature change.

Further, the control means sets the rotation speed of the rotating drum or the motor to a lower rotation speed than the normal rotation speed during the drying operation, and the clogging of the filter is carried out by the output signal of the temperature detection means and the output signal of the current detection means. Is notified, the number of rotations for detecting filter clogging can be reliably controlled to be constant even if the voltage, the amount of the material to be dried, or the like changes, and clogging detection accuracy can be improved.

Further, the control means sets the rotation speed of the rotating drum or the motor to approximately the lowest rotation speed at the start of the operation, and then sets the rotation speed to a lower rotation speed than the normal rotation speed during the operation of increasing the rotation speed to the normal rotation speed. Since the clogging of the filter is notified by the output signal of the detecting means and the output signal of the current detecting means, the apparatus is started with the PTC heater current lowered, and the power supply breaker is cut off by the inrush current of the PTC heater. Since no clogging occurs and the clogging of the filter can be detected in the initial stage of the operation start, the user can be reliably notified.

Further, the control means sets the rotation speed of the rotating drum or the motor to a lower rotation speed than the normal rotation speed for a certain period of time during the drying operation, and then performs a filter based on the output signal of the temperature detection means and the output signal of the current detection means. Since the clogging is notified, by operating at a low rotation speed for a certain period of time, the temperature inside the rotating drum can be made substantially constant, and the clogging detection accuracy can be improved.

[Brief description of the drawings]

FIG. 1 is a block diagram of a clothes dryer according to one embodiment of the present invention.

FIG. 2 is a sectional view of the clothes dryer.

FIG. 3 is a diagram showing a change in circulation temperature and current with time of the clothes dryer.

FIG. 4 is a diagram showing a change in the number of rotations of the clothes dryer when the filter clogging is detected.

FIG. 5 is an operation flowchart of the clothes dryer.

FIG. 6 is a flowchart for detecting filter clogging of the clothes dryer.

[Description of Signs] 1 Rotary drum 2 Heat exchange type double wing fan (blowing means) 3 PTC heater (heating means) 4 Filter 5 Motor 6 Temperature detecting means 7 Rotation detecting means 9 Control means 17 Current detecting means 20 Reporting means

──────────────────────────────────────────────────の Continued on the front page (72) Inventor Hiroyu Matsui 1006 Kazuma Kadoma, Osaka Pref. Matsushita Electric Industrial Co., Ltd. (72) Inventor Shunji 1006 Kadoma Kadoma Kadoma, Osaka Pref. In-company (56) References JP-A-4-256799 (JP, A) JP-A-58-7296 (JP, A) JP-A-63-181797 (JP, A) JP-A-6-15100 (JP, A) ) 62-182197 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) D06F 58/28

Claims (4)

(57) [Claims] 1. A rotating drum for drying clothes, a blowing means for circulating warm air into the rotating drum, and a positive characteristic temperature-sensitive resistance heater provided in a blowing path to the rotating drum.
And comprising heating means, and a filter provided in the air feed path,
A motor that rotationally drives the blowing unit or the rotating drum, a rotation detecting unit that detects a rotating speed or a rotating cycle of the rotating drum, the motor, and a control unit that controls a rotating speed of the motor or the heating unit, A temperature detection unit provided in a ventilation path to the heating unit; a current detection unit connected to the control unit for detecting a current of the heating unit; and a notification unit, wherein the control unit includes a rotation speed of the motor. Is set to be constant, and the clogging of the filter is notified by the output signal of the temperature detecting means and the output signal of the current detecting means. 2. The control unit sets the rotation speed of the rotating drum or the motor to a lower rotation speed than the normal rotation speed during the drying operation, and clogs the filter based on the output signal of the temperature detection unit and the output signal of the current detection unit. The clothes dryer according to claim 1, wherein the notification is made. 3. The control means sets the rotational speed of the rotating drum or the motor to a substantially minimum rotational speed at the start of the operation, and then sets the rotational speed to a lower rotational speed than the normal rotational speed during the operation of raising the rotational speed to the normal rotational speed. 2. The clothes dryer according to claim 1, wherein the clogging of the filter is notified by an output signal of the detecting means and an output signal of the current detecting means. 4. The control means sets a rotation speed of the rotating drum or the motor to a lower rotation speed than a normal rotation speed for a certain period during the drying operation, and then performs a filter based on an output signal of the temperature detection device and an output signal of the current detection device. The clothes dryer according to claim 1, wherein the clogging is notified.