JP3109308B2 - 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 have become widespread, and there has been a demand for clothes dryers that use a positive temperature characteristic heater to improve safety.

Conventionally, this type of clothes dryer has been disclosed in
No. 900900. That is, a positive temperature characteristic heater (hereinafter, referred to as a PTC heater)
And when the heater current increases, the blower fan capacity is controlled.

[0004]

In such a conventional clothes dryer, when the blower fan stops, the heater current decreases, so that the motor or the rotating drum rotates at a high speed so as to increase the heater current, and the safety is increased. Had the above problem. In particular, if the fan belt that transmits the rotational torque from the motor that drives the blower fan to the blower fan runs out,
Alternatively, when an opening / closing means such as a relay for controlling the opening / closing of the heater current has an open failure, the motor may rotate abnormally. Further, there is a problem that when the opening / closing means for the heater current is short-circuited, the heater is always in a heated state and the temperature in the rotating drum rises abnormally.

The present invention has been made to solve the above-mentioned problems, and has only a small number of erroneous operations. Only when an abnormality has occurred in the operation, the failure is reliably distinguished and reported, the heating of the PTC heater is stopped, and the rotation of the motor is further stopped. It is intended to stop.

[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. Of the positive temperature sensitive resistance heater
That a heating means, a motor for rotating the blower means or said rotary drum, a rotation detecting means for detecting a rotational speed such as the rotating drum or the motor, the rotary drum or the motor by controlling the motor current Rotation control means for controlling the number of rotations to a set number of rotations, opening and closing means for controlling the heating means, current detection means for detecting the current of the heating means, and an abnormal state detected by the output of the rotation detection means. Abnormality protection means , wherein the abnormality protection means is provided .
The step is performed by the rotation detecting means when the heating means is energized.
The detected rotation speed is equal to or higher than a predetermined rotation speed and the current detection
If the output of the unit is below the set value, an abnormal condition will be detected.
This is the first problem solving means.

Further, the abnormality protection means of the first means for solving the problem is that the rotation number detected by the rotation detection means when the heating means is not energized is higher than a predetermined rotation number and the output of the current detection means is higher than a set value. A second problem solving means is to detect an abnormal state in such a case.

Further, in addition to the first means for solving the above-mentioned problems, there is provided a starting control means for controlling the rotation after the motor is energized and energizing the heating means with a delay, and the abnormality protection means is provided with an output of the current detecting means before energizing the heating means. A third problem-solving means is to detect an abnormal state when is larger than a set value.

[0009]

According to the first aspect of the present invention, there is provided:
The number of rotations of the rotating drum or the motor is detected by the rotation detecting means and is controlled by the rotation control means. By detecting the abnormal state by the output of the rotation detection means and the output of the current detection means by the abnormality protection means, when the rotation of the blowing means for controlling the heating means or the opening and closing means of the heating means is abnormal, the abnormality is detected. It is possible to detect and stop the supply of electricity to the heating means, thereby improving safety.

[0010] Then, error protection means can be opened abnormality of the opening and closing means or if the heating means rotation stops air blowing means for controlling the heating means detects an abnormal condition when the generated, to the heating means and the motor Can be stopped, and safety can be improved.

Further, according to the second problem solving means, the abnormality protection means can detect an abnormal state when a short circuit abnormality of the opening / closing means of the heating means occurs, and stop the energization to the heating means and the motor. And abnormal heating can be prevented.

According to the third means for solving the problem, the abnormality protection means detects the abnormal state by the output of the current detection means after the motor reaches a predetermined number of revolutions and before the heating means is energized.
Short-circuit failure of the opening and closing means of the heating means can be detected,
Power supply to the heating means and the motor can be stopped, and safety can be improved.

[0013]

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

As shown in the figure, the rotating drum 1 is for storing and drying the object to be dried (clothing), and circulates warm air in the rotating drum 1 by a heat exchange type double-wing fan (blowing 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 includes a first temperature detecting means 6a and a second temperature detecting means 6b, and the first temperature detecting means 6a detects an exhaust gas temperature according to the temperature in the rotary drum 1. The second temperature detecting means 6b is for detecting the temperature of the suction air of the PTC heater 3. The rotation detecting means 7 includes the rotating drum 1
The magnet 8 is attached to the rotating drum 1 by three.
Six magnetic sensors are attached, and a magnetic sensor (not shown) is fixed to the main body to detect the rotation speed of the rotating drum 1.

The rotation control means 9 controls the number of rotations of the motor 5. The power semiconductor element 10 such as a bidirectional thyristor connected in series to the motor 5 and the output of the rotation detection means 7 rotate the rotation drum 1. Number of revolutions determining means 11 for determining the number of revolutions, number of revolutions setting means 12 for setting the number of revolutions of rotary drum 1, and number of revolutions comparing means for comparing the output of number of revolutions discriminating means 11 with the output of number of revolutions setting means 12 13, a pulse width control means 14 for controlling the conduction time of the power semiconductor element 10 by the output of the rotational speed comparison means 13, and a motor 5
The low-speed start means (start control means) 15 for setting the set rotation speed low at the time of start of the motor and energizing the motor 5 and then energizing the PTC heater 3 with a delay, and the rotation detected by the rotation detection means 7 The difference between the number of revolutions of the drum 1 and the number of revolutions set by the number of revolutions setting means 12 is compared by the number of revolutions comparing means 13, and the power semiconductor element 10 is controlled by the pulse width control means 14 to control the number of revolutions of the motor 5. I do. 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. The low-speed starting means 15 is
The rotation speed setting means 12 is controlled for a predetermined time (for example, 20 seconds) at the time of startup, and is set to a rotation speed (for example, 36 rpm) lower than the rotation speed (for example, 45 rpm) of the rotating drum 1 during normal operation. A delay time is provided for supplying power to the PTC heater 25 after the motor 5 starts rotating.
Further, the rotation number determination unit 11 may determine the rotation cycle of the rotating drum 1 based on the output of the rotation detection unit 7.

The current detecting means 16 includes the current transformer 1
7 and a current-voltage conversion circuit 18, which detects the input current of the PTC heater 3 and outputs the output to the current comparison setting means 1.
Enter 9 The current comparison setting means 19 compares the set current value of the PTC heater 3 with the output of the current detection means 16,
The output is input to the rotation speed setting means 12 to control the set rotation speed. Here, the set number of revolutions set by the number of revolutions setting means 12 is set such that the current of the PTC heater 3 does not exceed or fall below a predetermined current value.

The abnormality protection means 20 comprises a stopping means 21 and a notifying means 22, and receives the output of the rotation speed discriminating means 11 and the output of the current detecting means 16 and
When the rotation abnormality of the blowing means 2 or the short circuit failure of the opening / closing means 25 is detected by the
At 1, the switch 23 is turned off to stop the rotation of the rotary drum 1, and at the same time, the relay (opening / closing means) 25 connected in series with the PTC heater 3 is turned off, and the notifying means 22 notifies. The AC power supply 24 includes PTC heaters 3a, 3b
And the contacts 25a and 25b of the relay 25 are connected in series, respectively.

The operation of the above configuration will be described with reference to FIGS. 3 to 5. FIG. 3 is an operation flowchart of one embodiment of the present invention. After the initial setting, the motor 5 is turned on in step 32, and the number of rotations of the rotating drum 1 and the current of the PTC heater 3 are detected in step 33. At step 34, a delay time (5 seconds) is provided. At step 35, it is determined whether or not the abnormality counter N has reached the abnormality setting.
At step 7, the motor 5 is turned off. Step 38 is the rotating drum 1
It is determined whether or not the rotation speed has reached the set value. If the rotation speed is low, the abnormality counter N is incremented in step 39 and the process returns to step 32. When the rotational speed of the rotary drum 1 reaches the set value in step 38, the process proceeds to step 40. Step 40 is a subroutine for controlling the rotational speed of the rotary drum 1 at a constant low speed. The rotation speed set by the rotation speed setting means 12 is set to low speed (36 rpm) by the low speed starting means 15, and the difference between the rotation speed of the rotating drum 1 detected by the rotation detection means 7 and the rotation speed set by the rotation speed setting means 12 is set. Are compared by the rotational speed comparing means 13 and the pulse width controlling means 1
4 controls the power semiconductor element 10 to control the rotation speed of the motor 5 at a low speed. For this reason, the amount of air circulating to the rotating drum 1 is small, and the inrush current flowing to the PTC heater 3 can be suppressed to be small.

Next, in step 41, the current of the PTC heater 3 is compared with the set value (Is1). When the current of the PTC heater 3 is larger than the set value (Is1), it is determined that the relay 25 has short-circuited. In step 42, an abnormality is notified, and in step 43, the power is turned off. PTC at step 41
If the current of the heater 3 is equal to or less than the set value (Is1), the process proceeds to step 44, where it is determined whether a delay time of 20 seconds has elapsed. At this time, the relay 25
The TC heater 3 is not energized. When a predetermined delay time (20 seconds) elapses, at step 45, the relay 25
Is turned on, the PTC heater 3a is turned on, and the routine proceeds to step 46, where it is delayed for 30 seconds. Next, the process proceeds to a step 47, wherein the contact 25b of the relay 25 is closed and the PT
30 seconds after the C heater 3a is turned on, the PTC heater 3b is turned on and the routine proceeds to step 48.

At step 48, it is determined whether or not the rotation speed of the rotating drum 1 is lower than a set value (30 rpm). If the rotation speed is less than the set value, it is determined that the rotating drum 1 has slipped and the rotation speed has become abnormal. Notify, step 50
To stop the rotation of the motor 5. If the rotational speed of the rotary drum 1 is higher than the set value (30 rpm) in step 48, the process proceeds to step 51, and it is determined in step 51 whether the current of the PTC heater 3 is smaller than the set value (Is2). P
If the current of the TC heater 3 is smaller than the set value, step 5
Then, the process proceeds to step S2, in which the blower means is notified, such as when the fan belt has run out. At step S53, the PTC heater 3 is turned off. PTC at step 51
If the current of the heater 3 is equal to or more than the set value (Is2), the process proceeds to step 55, where a delay time of 30 seconds is provided in step 55, and then in steps 56 and 57, the rotation speed of the rotating drum 1 is reduced to the normal rotation speed ( For example, control is performed at 45 rpm).

The details of the operation at this time will be described with reference to FIG. 4. A one-second timer is set in step 61, a current is detected by the current detecting means 16 in step 62, and a current comparison setting means 19 is detected in step 63. To calculate the error from the current set value. The calculation result is input to the rotation number setting means 12, and in step 64, the rotation cycle of the rotating drum 1 is calculated and set based on the calculation result. And step 6
The cycle Ts calculated in step 5 is compared with the maximum cycle Tsmax,
Step 6 if the cycle Ts is greater than the maximum cycle Tsmax
The process proceeds to step S6, where the maximum cycle Tsmax is set as the set cycle. Period Ts
Is smaller than the maximum period Tsmax, the process proceeds to a step 67, wherein the calculated and set period Ts is compared with the minimum period Tsmin.
Step 6 if the cycle Ts is smaller than the minimum cycle Tsmin
Proceeding to step 8 and setting the minimum cycle Tsmin as the set cycle, step 6
Go to 9. When the cycle Ts is larger than the minimum cycle Tsmin, the process proceeds to step 69. Therefore, the rotation speed setting means 12
Is set to be smaller than the maximum cycle Tsmax and larger than the minimum cycle Tsmin.

In step 69, it is determined whether or not a rotation detection signal has been input from the rotation detection means 7. If the rotation detection signal has been input, in step 70, the rotation cycle T
Is detected, and the routine proceeds to step 71. In step 71, the rotation speed comparison means 13 detects an error from the set period Ts and proceeds to step 72, where it is determined whether or not the detected error is within the set range. If the detected error is within the set range, the process proceeds to the next step. If the detected error is not within the set range, the process proceeds to step 73, where the control phase is calculated and set by the pulse width control means 14, and the rotation speed of the rotary drum 1 is controlled to the rotation speed set by the rotation speed setting means 12. Then proceed to the next step. Step 69
If the rotation detection signal is not input from the rotation detection means 7, the process proceeds to the next step.

FIGS. 5A to 5E are timing charts showing the operation contents shown in the flowchart of FIG. The operation starts at time t0 and the motor 5 is turned on. After the delay time, the PTC heater 3a is turned on at time t1 and the time t2
Turns on the PTC heater 3b. During this time, the rotating drum 1
Is constant at a low rotation speed (36 rpm). Heater 3
At the time t3 after the delay of b, the current of the PTC heater 3 is detected at the time t3 to control the rotation speed of the rotary drum 1 or the heat exchange type two-blade fan 2 so that the power of the PTC heater 3 is controlled to be constant.

As described above, according to this embodiment, the rotation detecting means 7 for detecting the number of rotations of the rotary drum 1 and the rotation control means for controlling the current of the motor 5 to control the number of rotations of the rotary drum 1 to the set number of rotations. 9 and a relay 25 for opening and closing the PTC heater 3
Current detecting means 16 for detecting the current of the PTC heater 3
And the abnormality protection means 20 for stopping the heating of the PTC heater 3 and the rotation of the rotary drum 1 when an abnormal state is detected by the outputs of the current detection means 16 and the rotation detection means 7, so that the relay 25 has a short-circuit failure. For example, when an abnormality occurs in the current of the PTC heater 3 or when the current of the PTC heater 3 decreases due to a decrease in the rotation speed of the heat exchange type double-blade fan 2, the heating of the PTC heater 3 and the rotation of the rotating drum 1 are performed.
Alternatively, the rotation of the heat exchange type double-wing fan 2 can be stopped, and safety can be improved. Further, at the time of startup, the amount of circulating air can be reduced, the inrush current flowing through the PTC heater 3 can be reduced, and stable startup can be achieved.

In the above-described embodiment, the case where the rotary drum 1 and the fan of the heat exchange type double-blade fan 2 are driven by one motor 5 has been described. is there. The same applies to the case where the rotation speed of the motor 5 is detected.

[0026]

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 A heating means comprising a positive-characteristic temperature-sensitive resistance heater provided in a motor, a motor for rotating the blower means or the rotating drum, and a rotation for detecting the number of rotations or the rotation period of the rotating drum or the motor. Detecting means;
Rotation control means for controlling the motor current to control the rotation speed of the rotary drum or the motor at a set rotation speed, opening and closing means for controlling the heating means, and current detection means for detecting the current of the heating means And abnormal protection means for detecting an abnormal state based on the output of the rotation detecting means and the output of the current detecting means, so that when an abnormality occurs in the blowing means or the heating means such as when the heating means fails, heating is stopped. And the safety can be improved by stopping the motor.

The abnormality protection means detects an abnormal state when the number of rotations detected by the rotation detection means when the heating means is energized is equal to or higher than a predetermined number of rotations and the output of the current detection means is equal to or less than a set value. After the motor operation starts, the abnormality protection unit can check the signal from the rotation detection unit to detect an abnormal current drop of the heating unit, determine whether the rotation of the blower unit has stopped, or determine the electrical connection failure of the heating unit. Since the rotation and the heating of the heating means can be stopped, it can be distinguished from the rotation failure of the motor. In addition, the abnormality protection means can not only stop the heating in the event of an abnormality, but also can notify the user or the person in charge of the repair of the failure by discriminating the content of the failure at an early stage.

The abnormality protection means detects an abnormal state when the number of rotations detected by the rotation detection means when the heating means is not energized is greater than a predetermined number of rotations and the output of the current detection means is greater than a set value. Therefore, the abnormality protection means can detect an abnormal state when a short circuit abnormality or the like of the opening / closing means of the heating means occurs, and can stop the power supply to the heating means and the motor, thereby preventing abnormal heating. be able to.

Further, there is provided start-up control means for controlling the rotation after energizing the motor and energizing the heating means with a delay, and the abnormality protection means detects an abnormal state when the output of the current detection means is equal to or more than a set value before energizing the heating means. Since the detection is performed, the abnormality protection unit detects the abnormal state by the output of the current detection unit before the heating unit is energized after reaching the predetermined number of rotations after the motor is energized, and particularly, the short-circuit failure of the opening and closing unit of the heating unit early and further. The determination can be made reliably, the heating of the heating means and the rotation of the rotating drum or the motor can be stopped, and safety 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 an operation flowchart of the clothes dryer.

FIG. 4 is a subroutine flowchart for controlling the number of revolutions of the clothes dryer.

5 (a) to 5 (e) are operation time charts at the start of operation of the clothes dryer.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 rotating drum 2 heat exchange type double wing fan (blowing means) 3 PTC heater (heating means) 5 motor 7 rotation detection means 9 rotation control means 16 current detection means 20 abnormality protection means 25 relay (opening / closing means)

Continuation of front page (56) References JP-A-63-181797 (JP, A) JP-A-4-220297 (JP, A) JP-A-3-284299 (JP, A) JP-A-3-143499 (JP) , A) JP-A-4-99600 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) D06F 58/02 D06F 58/28

Claims (3)

(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, a motor for rotating the blower means or said rotary drum, a rotation detecting means for detecting the rotational speed or the rotational period such as the rotary drum or the motor, the rotary drum by controlling the motor current Or rotation control means for controlling the rotation speed of the motor or the like to a set rotation speed, opening and closing means for controlling the heating means, current detection means for detecting the current of the heating means, the output of the rotation detection means and Abnormality protection means for detecting an abnormal state by an output of the current detection means , wherein the abnormality protection means
Detected by the rotation detecting means when the heating means is energized
When the rotation speed is equal to or higher than a predetermined rotation speed and the current detection
A clothes dryer configured to detect an abnormal state when the force is equal to or less than a set value . 2. A rotary drum for drying clothes, blowing means for circulating warm air into the rotary drum, and a positive characteristic temperature-sensitive resistance heater provided in a blowing path to the rotary drum.
And comprising heating means, a motor for rotating the blower means or said rotary drum, a rotation detecting means for detecting the rotational speed or the rotational period such as the rotary drum or the motor, the rotary drum by controlling the motor current Or rotation control means for controlling the rotation speed of the motor or the like to a set rotation speed, opening and closing means for controlling the heating means, current detection means for detecting the current of the heating means, the output of the rotation detection means and Abnormality protection means for detecting an abnormal state by an output of the current detection means , wherein the abnormality protection means
The rotation detecting means detects when the heating means is not energized.
Rotation speed is equal to or higher than a predetermined rotation speed and the current detection means
If the output is higher than the set value, an abnormal condition will be detected.
Clothes dryer. 3. A rotary drum for drying clothes, blowing means for circulating warm air into the rotary drum, and a positive characteristic temperature-sensitive resistance heater provided in a blowing path into the rotary drum.
And comprising heating means, a motor for rotating the blower means or said rotary drum, a rotation detecting means for detecting the rotational speed or the rotational period such as the rotary drum or the motor, the rotary drum by controlling the motor current Or rotation control means for controlling the rotation speed of the motor or the like to a set rotation speed, opening and closing means for controlling the heating means, current detection means for detecting the current of the heating means, the output of the rotation detection means and An abnormality protection means for detecting an abnormal state based on an output of the current detection means, and a rotation control after the motor is energized.
And starting control means for energizing the heating means with a delay.
The abnormality protection means detects the current before the heating means is energized.
If the output of the unit is higher than the set value, an abnormal condition will be detected
Seared clothes dryer.