JPH07265599A - Clothes dryer - Google Patents

Abstract

PURPOSE:To detect filter blinding, improve detection accuracy without Doing influenced by a temperature change or a voltage change so as to prevent user's misusage in a clothes dryer which dries clothes by circulating warm wind into a rotary drum rotationally-driven by a motor. CONSTITUTION:Warm wind is made to circulate by a thermo-exchange type double wing fan into a rotary drum 1 which dries clothes, and a PCT heater 3 and a filter are provided on an air blowing pathway to the rotary drum 1 and the rotary drum 1 and the thermo-exchange type double fan are rotationally-driven by a motor 5 and the motor rotating speed is controlled by a control means 9. A temperature detecting means 6 is provided on the air blowing pathway to the PCT heater 3 and an electric current of the PCT heater 3 is detected by an electric current detecting means 17 connected to the control means 9. The control means 9 sets the motor 5 rotating speed approximately to a constant rotating speed and filter blinding is detected by both an output signal from the temperature detecting means 6 and an output signal from the electric current detecting means 17 and is informed by an informing means 20 after the completion of the dry operation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clothes dryer which circulates warm air in a rotary drum which is 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 in a rotary drum for drying clothes. A clothes dryer that reports clogging has been proposed.

Conventionally, a clothes dryer of this type has been disclosed in Japanese Patent Laid-Open No. Sho 55.
It was configured as shown in Japanese Patent Publication No. 16631. That is, a current change of a positive 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 of a filter is notified.

[0004]

In such a conventional clothes dryer, the PTC heater current changes depending on the intake air temperature, the air volume, and the voltage, and the PTC due to the seasonal changes in summer and winter, the voltage change, and the cloth amount. 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 by only the current change considering all the fluctuations. There is a problem that it is impossible to detect the clogging state. Further, if the clogging is notified during driving, there is a problem that the user is suspicious when the clogging is notified immediately after cleaning the filter.

The present invention solves the above conventional problems.
The purpose of the present invention is to detect clogging of a filter without being affected by temperature changes, voltage changes, air flow changes, or use conditions, and to appropriately notify the clogging.

[0006]

In order to achieve the above object, the present invention provides a rotating drum for drying clothes, an air blowing means for circulating warm air into the rotating drum, and an air blowing path into the rotating drum. A PTC heater provided in, a filter provided in the air blowing path, a motor that rotationally drives the air blowing unit or the rotating drum, and a rotation detecting unit that detects the number of rotations or the rotation cycle of the rotating drum, the motor, or the like. Control means for controlling the number of revolutions of the motor and the PTC heater, temperature detecting means provided in a ventilation path to the PTC heater, and the PTC connected to the control means.
A current detection means for detecting the current of the heater, a notification means,
A user sets operation setting means for setting operation contents, the control means sets the rotation speed of the motor to a substantially constant rotation speed, and outputs an output signal of the temperature detection means and an output signal of the current detection means. The first problem solving means is to detect the clogging of the filter by the above, and to notify the clogging after the completion of the drying operation.

In the control means of the first problem solving means, the operation course can be set by a special setting method different from usual by the operation setting means, and the rotating drum or the motor rotating speed is almost constant at the initial stage of operation. The second problem solving means is that after the setting, the clogging of the filter is detected by the output signal of the temperature detecting means and the output signal of the current detecting means to notify the clogging of the filter.

Further, the control means of the first problem solving means sets the clogging detection rotation speed during the normal operation and the clogging detection rotation speed of the driving course set by a special method to be the same. This is the third means for solving the problems.

[0009]

According to the first means for solving the above problems, the present invention provides:
The clogging of the filter can be detected by the intake air temperature of the PTC heater and the electric power applied to the PTC heater, and the clogging can be detected accurately regardless of the voltage change and temperature change. It can prevent anxiety and misuse.

Further, the second problem solving means makes it possible to check the clogging state at the initial stage of operation at the time of repairing a fault or at the time of manufacturing.

Furthermore, the third problem solving means makes it possible to make the clogging detection conditions the same during the normal drying operation and the check operation, so that erroneous detection during the check operation can be prevented.

[0012]

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

As shown in the figure, a rotary drum 1 is for accommodating and drying an object to be dried (clothes), and hot air is circulated in the rotary drum 1 by a heat exchange type double-blade fan (blowing means) 2. The heat exchange type double-blade fan 2 circulates warm air in the rotary drum 1 and at the same time takes in air from the outside to cool the fan and dehumidify the circulating air in the rotary drum 1. P
The TC heater (heating means) 3 is arranged in the air blowing path to the rotary drum 1, that is, in the circulating air intake, and heats the circulating air.

The filter 4 is provided in the air blowing path of the heat exchange type double-blade fan 2, that is, in the air outlet of the rotary drum 1. When the filter 4 is clogged with lint and the like, the amount of blown air is reduced, the heating power of the PTC heater 3 is reduced, the drying time is lengthened, and the drying efficiency is also reduced. Motor 5
Is for rotating and driving the rotary drum 1 and the heat exchange type double-blade fan 2. By controlling the rotation speed of the motor 5, the rotation speeds of the rotary drum 1 and the heat exchange-type double-blade fan 2 can be controlled. The amount of heat generation can be controlled and the current can be controlled. The temperature detection means 6 detects the temperature of the air sucked into the PTC heater 3.

The rotation detecting means 7 detects the number of rotations of the rotary drum 1. Two to six magnets 8 are attached to the rotary drum 1, and a magnetic sensor (not shown) is fixed to the main body to rotate the rotary drum. The number of rotations of 1 is detected. The control means 9 is the motor 5
For controlling the rotation speed of the rotary drum 1 and the PTC heater 3, and a rotation speed comparing means for comparing the output of the rotation detecting means 7 and the output of the rotation speed setting means 10 with the rotation speed setting means 10 for setting the rotation speed of the rotary drum 1. 11, a conduction angle control means 13 for controlling the conduction angle of the bidirectional thyristor 12 connected in series to the motor 5 by the output of the rotation speed comparison means 11, and a low speed starting means for lowering the set rotation speed when the motor 5 is started. 14, the temperature control means 15 and the clogging detection level setting means 16 for inputting the output of the temperature detection means 6, and the clogging notification determination for comparing the output of the clogging detection level setting means 16 and the output of the current detection means 17. And means 18.

The rotation speed comparison means 11 compares 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, and the conduction angle control means 13 causes the bidirectional thyristor. 12 to control the motor 5
Control the rotation speed of. Phase control can be 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. By doing so, stable rotation control of the motor 5 and the rotary drum 1 can be performed.

The output of the temperature detecting means 6 for detecting the temperature of the circulating air of the rotary drum 1 is input to the temperature control means 15, and the output of the temperature control means 15 causes the PTC heater 3 to operate.
relay contacts 19a and 19b respectively connected to a and 3b
Is controlled to control the temperature of the circulating air by controlling the on / off of the PTC heaters 3a and 3b. Further, the temperature detecting means 6
The output of the clogging detection level setting means 16 and the output of the current detection means 17 are input to the clogging notification determination means 18, and the notification means 20 notifies the clogging of the filter 4. .

The operation setting means 21 is connected to the control means 9 to operate and set a plurality of types of driving courses, and is inputted to the rotation number setting means 10 so that the number of rotations of the rotary drum 1 can be changed according to the driving courses. It is possible to set to
The temperature inside the rotary drum 1 is controlled according to the output of the temperature detection means 6 by inputting to the temperature control means 15. Furthermore, the check driving course can be set by a special setting method different from the usual one.

The current detecting means 17 is the current transformer 2
2 and the current-voltage conversion circuit 23, detects the input current of the PTC heater 3, and outputs the output from the current comparison setting means 2
Enter in 4. The current comparison setting means 24 compares the set current value of the PTC heater 3 with the output of the current detection means 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 so that the current of the PTC heater 3 does not exceed or fall below a predetermined current value.

The output of the current detection means 17 is also input to the clogging notification determination means 18 together with the output of the clogging detection level setting means 16 which calculates the clogging detection level by the output of the temperature detection means 6, and the motor 5 The output of the clogging detection level setting means 16 and the output of the current detection means 17 are compared in a state where the rotation speed is set to a constant value, and the notification means 2
When 0, the clogging of the filter 4 is notified. That is, by controlling the rotation of the heat exchange type double-blade fan 2, the blowing condition at the time of detecting clogging is set to be constant.

The operation of the above structure 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 clogging detection method according to the present invention. In the figure, the input electric power P of the PTC heater 3 is the temperature difference ΔT between the Curie temperature Tq and the intake air temperature T.
Is represented by the product of the heat dissipation coefficient H, and P = H (Tq-T). When the filter 4 is clogged, the heat radiation coefficient H is lowered due to the decrease in the air volume due to the clogging, so that the Curie temperature Tq is constant, so the heat radiation coefficient H can be obtained from the input power P and the intake air temperature T, and the clogging is prevented. Can be estimated.

Characteristic A in FIG. 3 shows the relationship between the input current I of the PTC heater 3 and the intake air temperature T when the amount of clothes is small, and the characteristic A'is when the amount of clothes is large and the characteristic B is when the filter is clogged. Shows the characteristics of. Is is the PTC heater 3 for the intake air temperature T for determining clogging.
3 shows the clogging detection level of the input current I of FIG. The detection level Is can be set approximately linearly as Is = K−kT, corresponding to the intake air temperature T. Here, K and k are constants.

Next, the clogging is detected by controlling the rotation speed of the rotary drum 1, that is, the rotation speed of the motor 5 to be constant. That is, as shown in FIG. 4, at the time t0, the low-speed starting means 14 changes the set rotation speed of the rotation speed setting means 10 to the low-speed rotation speed n1 (the rotation speed 4 of the rotary drum 1 in the normal operation).
For example, 36 rpm is set for 5 rpm, and the operation is started. Then, at a time t1 when a predetermined time (for example, 3 minutes) has elapsed, the rotational speed setting means 10 calculates the set rotational speed according to the temperature detected by the temperature detecting means 6,
The rotation speed of the motor 5 is controlled based on this set rotation speed, and the rotation speed is gradually increased. The final upper limit rotation speed n2 is reached, and the rotation speed is substantially constant after time t2. The clogging is detected 1-2 minutes before the time t1.

Next, the operation will be described in detail with reference to FIG. 5, starting at step 30, initializing at step 31, detecting signal input from the operation setting means 21 at step 32, and step 33. Then, it is judged whether it is a normal dry operation course or a check operation by a special operation setting. In the normal drying operation, the motor 5 is soft-started in step 34. That is, the low speed starting means 1
4, the rotation speed setting means 10 is set to the low rotation speed n1 to start the rotation.

Then, in step 35, the set rotational speed is set to the lowest controllable rotational speed (which may be lower than n1) to detect clogging. Next, in step 36, the current of the PTC heater 3 is detected by the current detecting means 17, is input to the rotation speed setting means 10 via the current comparison setting means 24, and the set rotation speed is calculated in step 37 to set this. Based on the number of rotations, the number of rotations of the motor 5 is controlled in step 38, the process proceeds to step 41 through steps 39 and 40, and in step 35, when the clogging notification flag is turned on, clogging notification is performed.

The clogging detection operation will be described with reference to FIG. 6. In step 50, the clogging detection subroutine is started, and in step 51, the rotation speed of the rotary drum 1 is controlled to be substantially constant at the minimum rotation speed n1. After delaying for a fixed time (for example, 3 minutes) in step 52, the temperature of the circulating air is detected by the temperature detecting means 6 in step 53. Next, in step 54, the clogging detection level setting means 15
Then, the detection level Is shown in FIG. 3 is calculated. Then, in step 55, the current I of the PTC heater 3 is detected by the current detection means 17, and in step 56, the detection level I
Compare s with the current I. When the filter 4 is clogged and the amount of circulating air is reduced, and if I <Is, the clogging notification flag is turned on in step 57, and an output is output from the clogging notification determination means 18 after the end of operation to notify. The means 20 enables clogging notification. And
In step 58, the clogging detection flag is turned on, the process proceeds to step 59, and the process returns to step 35 of FIG.

Next, in step 33 of FIG. 5, when the check operation course is set by the operation setting means 21 by a special operation, the process proceeds to step 43, and a check operation course different from the normal display is displayed. The display is performed, and the soft start is performed in step 44. The clogging detection subroutine of step 45 is the same as that of step 35, and the clogging detection rotation number at this time is set to the same value to minimize the detection error between the normal dry operation course and the check operation course. In step 46, it is determined whether the clogging notification flag is on or off. If the clogging notification flag is on, the clogging notification is performed in step 47.

As described above, according to this embodiment, after the number of rotations of the rotary drum 1 is set to be constant at a low speed during the drying operation,
Before increasing to the normal rotation speed, the filter 4 is activated by the output signal of the temperature detecting means 6 and the output signal of the current detecting means 17.
Since it detects clogging of the filter, it can detect clogging of the filter without being affected by temperature changes and voltage changes, improving the detection accuracy.Also, it notifies after the end of operation, so it does not cause suspicion of the user. Misuse can be prevented.

[0029]

As described above, according to the present invention, the rotary drum for drying clothes, the air blowing means for circulating the warm air into the rotary drum, and the P provided in the air blowing path into the rotary drum.
A TC heater, a filter provided in the air blowing path, a motor for rotationally driving the air blowing means or the rotating drum, a rotation detecting means for detecting the number of rotations or a rotation cycle of the rotating drum, the motor, etc. Control means for controlling the rotation speed and the PTC heater, and the PTC
The temperature detection means provided in the air blowing path to the heater, the current detection means connected to the control means for detecting the current of the PTC heater, the notification means, and the operation setting means for the user to set the operation content The control means sets the rotation speed of the motor to a substantially constant rotation speed, detects clogging of the filter by the output signal of the temperature detection means and the output signal of the current detection means, and after completion of the drying operation. Since the clogging is notified, the intake temperature of the PTC heater and the P
The clogging of the filter can be detected by the electric power applied to the TC heater, the clogging can be accurately detected regardless of the voltage change and the temperature change, and the clogging is notified after the completion of the drying operation. Also, it is possible to prevent misuse such as cleaning the filter while driving.

The control means can set the operation course by a special setting method which is different from usual by the operation setting means, and after setting the rotating drum or the motor rotation speed to a substantially constant rotation speed at the beginning of the operation, the temperature detecting means. Since the clogging of the filter is detected and notified by the output signal of and the output signal of the current detection means, in the check driving course set by the special operation setting, the clogging is notified at the initial stage of operation, It is possible to shorten the check time at the time of trouble repair or manufacturing.

Further, since the control means sets the clogging detection rotation speed during the normal operation and the clogging detection rotation speed of the driving course set by a special method to be the same, the control means is set to be the same as during the normal drying operation. The conditions for detecting clogging during the check operation can be made the same, and the detection error during the check operation can be almost eliminated.

[Brief description of drawings]

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

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

FIG. 3 is a diagram showing changes in circulating temperature and current of the clothes dryer over time.

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 rotary drum 2 heat exchange type double-blade fan (blowing means) 3 PTC heater (heating means) 4 filter 5 motor 6 temperature detection means 7 rotation detection means 9 control means 17 current detection means 20 notification means 21 operation setting means

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shoji Akira 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (3)

[Claims] 1. A rotating drum for drying clothes, a blowing unit for circulating warm air into the rotating drum, a heating unit provided in a blowing route into the rotating drum, and a filter provided in the blowing route. A motor for rotationally driving the blower means or the rotary drum; a rotation detection means for detecting the rotation speed or rotation cycle of the rotary drum, the motor or the like; and a control means for controlling the rotation speed of the motor and the heating means. A temperature detecting means provided in a blowing path to the heating means, a current detecting means connected to the control means for detecting a current of the heating means, an informing means, and an operation setting means for a user to set operation contents. The control means sets the rotation speed of the motor to a substantially constant rotation speed, and the filter is controlled by an output signal of the temperature detection means and an output signal of the current detection means. -A clothes dryer that detects clogging of the clothes and notifies you when the drying operation is complete. 2. The control means can set the driving course by a special setting method different from usual by the operation setting means,
3. The filter clogging is detected and notified by the output signal of the temperature detection means and the output signal of the current detection means after the rotation drum or the motor rotation speed is set to a substantially constant rotation speed at the initial stage of operation. The described clothes dryer. 3. The control means sets the clogging detection rotation speed during normal driving to be the same as the clogging detection rotation speed of a driving course set by a special method.
The described clothes dryer.