JP3185487B2 - 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.

The present invention has been made to solve the above-mentioned problem, and has a small malfunction. Only when an abnormality occurs in the operation, the failure is reliably distinguished and notified, 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. and heating means provided in, it said blowing means
A motor for rotating the pre said rotary drum, a switching means for controlling said heating means, and current sensing means for sensing the current of the heating means, the rotating drum or the motor
Rotation detection means for detecting the number of rotations or rotation cycle such as
And the number of rotations detected by the rotation detecting means is a predetermined number of times.
When the output of the current detecting means is equal to or less than a set value when the heating means is energized and the number of turns is equal to or more than one, the operation of turning off and on the opening and closing means is performed at least once, and then the current detection is performed again. A first problem solving means is provided with abnormality detecting means for detecting an abnormal state when the output of the means becomes equal to or less than a set value.

[0007] In addition to the first means for solving the problems,
Rotation detecting means for detecting a rotation speed or a rotation cycle of a rotating drum or a motor, etc., wherein the abnormality detection means detects an abnormal state when the rotation speed detected by the rotation detection means is equal to or higher than a predetermined rotation speed. This is defined as the second problem solving means.

Further, the heating means and the opening / closing means of the first means for solving the problems are divided into a plurality of parts, and the abnormality detecting means turns on the opening / closing means one by one at a predetermined time. A third problem solving means is to detect an abnormal state when the output of the current detecting means becomes equal to or less than a set value within a predetermined time after turning on of the power supply.

[0009]

According to the first aspect of the present invention, there is provided:
When an abnormality occurs in the rotation of the blowing means for controlling the heat generation amount of the heating means, it is detected that the rotation is abnormal, the power supply to the heating means can be stopped, and safety can be improved. Further, when the current value detected by the current detecting means becomes equal to or less than the set value, the operation of turning off and on the opening and closing means is performed at least once, so that the opening and closing means is momentarily shut down by power failure or mechanical vibration. Erroneous detection when the switch is turned off can be prevented.

According to the second problem solving means, the abnormality detecting means detects only when the rotational speed detected by the rotational detecting means is equal to or higher than a predetermined rotational speed, so that the rotational speed of the rotating drum or the motor decreases. This can prevent erroneous detection when the current of the heating means is reduced.

According to the third problem solving means, the abnormality detecting means is turned on one by one at a predetermined time when the open / close means is once turned off and then turned on again.
Inrush current of the heating means can be reduced, and safety can be improved. Further, the abnormality detecting means detects an abnormal state only when the output of the current detecting means becomes equal to or less than the set value within a predetermined time after all of the switching means are turned on. It is possible to prevent erroneous detection when the opening / closing means is turned off due to unusual vibration or the like.

[0012]

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, a rotary drum 1 is for storing and drying an object to be dried (clothing), and hot air is circulated in 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 PTC 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 attached to the exhaust port of the rotating drum 1 and has a PTC
This is for detecting the temperature of the intake air of the heater 3. The rotation detecting means 7 detects the number of rotations of the rotating drum 1. Two to four magnets 8 are attached to the rotating drum 1, and a magnetic sensor (not shown) is fixed to the main body to rotate the rotating drum 1. Detect the number.

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
And a low-speed start-up means (start-up control means) 15 for setting the set number of revolutions low at the time of start-up and energizing the motor 5 and then energizing the PTC heater 3 with a delay.

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 12 is compared by the rotation speed comparison means 13, and the power semiconductor element 10 is controlled by the pulse width control means 14. 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. The low-speed starting unit 15 controls the rotation speed setting unit 12 for a predetermined time (for example, 20 seconds) when the motor 5 is started, and the rotation speed of the rotating drum 1 during normal operation (for example, 45 rpm).
Is set to a lower rotation speed (for example, 36 rpm), and a delay time is provided for energizing the PTC heater 3 after the motor 5 starts rotating. Also, the rotation number discriminating means 11
Alternatively, the rotation cycle of the rotating drum 1 may be determined from the output of the rotation detecting means 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 detecting means 20 comprises a stopping means 21 and a notifying means 22. The output of the rotational speed determining means 11 and the output of the current detecting means 16 are inputted to the abnormality detecting means 20.
When the rotation abnormality of the air blowing means 2 is detected by the current detecting means 16 and the power semiconductor element 10 is turned off by the stopping means 21 and the motor 5 is turned off, and the rotation of the rotary drum 1 is stopped. The relay (opening / closing means) 23 connected in series is turned off, and the notification is made by the notification means 22.

Here, when the output of the current detecting means 16 becomes equal to or less than the set value when the PTC heater 3 is energized, the abnormality detecting means 20 performs at least one operation of turning off the relay 23 and turning it on again. Thereafter, when the output of the current detecting means 16 becomes lower than the set value again, the abnormal state is detected.

The PTC heater 3 is a PTC heater 3
a, 3b and the contacts 23a, 23b of the relay 23
Are connected in series, and the abnormality detecting means 20 turns on the contacts 23a and 23b of the relay 23 one by one at a predetermined time, and detects the current within a predetermined time after all the contacts 23a and 23b are turned on. When the output of the means 16 becomes equal to or less than the set value, an abnormal state is detected.
24 is an AC power supply and 25 is a power switch.

The operation of the above configuration will be described with reference to FIGS. 3 to 6. FIG. 3 is an operation flowchart of an embodiment of the present invention. In step 30, the power switch 25 is turned on to start operation. After the initial setting in step 31, the motor 5 is turned on in step 32, and the process proceeds to step 33. Step 33 is a subroutine for controlling the rotation speed of the rotary drum 1 to be constant at a low speed. Low-speed starting means 15
To set the rotation speed of the rotation speed setting means 12 to a low speed (36r
pm), the number of rotations of the rotating drum 1 detected by the rotation detecting means 7 is compared with the set number of rotations from the number-of-rotations setting means 12 by the number-of-rotations comparing means 13, and the pulse width control means 14 controls the power semiconductor. The number of rotations of the motor 5 is controlled to be low by controlling the element 10. For this reason, the rotating drum 1
The amount of circulating air to the PTC heater 3 is small, and the inrush current flowing to the PTC heater 3 can be suppressed to a small value.

Next, at step 35, the contact 23a of the relay 23 is turned on, the PTC heater 3a is turned on, and the routine proceeds to step 36, where it is delayed for 30 seconds. Next, step 3
7, the contact 23b of the relay 23 is closed and the PTC heater 3b is turned on 30 seconds after the PTC heater 3a is turned on.
Is turned on and the routine proceeds to step 38, where a delay of 30 seconds is made again.

In step 39, it is detected whether there is any abnormality in the heat exchange type two-blade fan 2, that is, whether the fan belt is broken. The operation at this time will be described in detail with reference to FIG. 4. In step 50, it is determined whether or not the rotation speed of the rotary drum 1 is lower than a set value (30 rpm). This is due to the blowing means 2
This is to prevent erroneous detection when the rotation speed of the PTC heater 3 decreases and the current flowing through the PTC heater 3 decreases. Step 5
If the number of rotations of the rotary drum 1 is higher than the set value (30 rpm) at 0, the process proceeds to step 51, and it is determined at step 51 whether the current of the PTC heater 3 is smaller than the set value Is. If the current of the PTC heater 3 is larger than the set value Is, the process proceeds to the next step. If less than the set value Is, step 52
To turn off the PTC heaters 3a and 3b,
3. Delay 1.5 seconds.

In steps 54 to 56, P
The PTC heater 3b turns on 20 seconds after the TC heater 3a turns on. Then, in step 57, the timer 1
Is cleared, and it is determined again in steps 58 and 59 whether or not the current of the PTC heater 3 is smaller than the set value Is until the timer 1 elapses 60 seconds. If it does not become less than the set value Is within 60 seconds, the process proceeds to the next step. If the difference is less than the set value Is within 60 seconds, the process proceeds to step 60, where a fan belt breakage abnormality is detected and the abnormality is notified by the notifying unit 22, and the PTC heater 3 is turned off in step 61, and the motor 5 is turned on in step 62. Turn off.

Next, if there is no abnormality in the heat exchange type double-blade fan 2 in step 39 in FIG. 3, in steps 40 and 41, the rotation speed of the rotary drum 1 is controlled to a normal rotation speed (for example, 45 rpm). Then, it is determined in step 42 whether or not drying has been completed. If completed, the drying operation is terminated in step 43. If not, the process returns to step 39.

Here, the details of the operations in steps 40 and 41 will be described with reference to FIG. 5. A one-second timer is set in step 70, and the current is detected by the current detecting means 16 in step 71. At 72, an error from the current set value is calculated by the current comparison setting means 19.
The calculation result is input to the rotation number setting means 12, and in step 73, the rotation cycle of the rotating drum 1 is calculated and set based on the calculation result. Then, the cycle Ts calculated and set in step 74
Is compared with the maximum period Tsmax, and the period Ts becomes the maximum period Tsmax.
If it is larger, the process proceeds to step 75, where the maximum period Tsmax
Is the set cycle. If the cycle Ts is smaller than the maximum cycle Tsmax, the process proceeds to step 76, where the calculated and set cycle Ts is compared with the minimum cycle Tsmin. Proceed to step 78. If the cycle Ts is larger than the minimum cycle Tsmin, the process proceeds to step 78. Therefore, the set period T set by the rotation speed setting means 12
s is set smaller than the maximum cycle Tsmax and larger than the minimum cycle Tsmin.

In step 78, 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 79, the rotation period T
Is detected and the routine proceeds to step 80. In step 80, the rotation speed comparison means 13 detects an error from the set period Ts, and the process proceeds to step 81, where it is determined whether 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 82, 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 78
If the rotation detection signal is not input from the rotation detection means 7, the process proceeds to the next step.

FIGS. 6A to 6E are timing charts showing the operation contents shown in the flowchart of FIG. The operation is started 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 time t2
To turn 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 time of b, the current of the PTC heater 3 is detected at a time t3 to control the rotation speed of the rotary drum 1 or the heat exchange type double-blade fan 2 so that the power of the PTC heater 3 is controlled to be constant.

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.

[0030]

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 Heating means provided in the air blower means and
A motor for rotating the fine said rotary drum, a switching means for controlling said heating means, and current sensing means for sensing the current of the heating means, a said rotary drum or the motor
Rotation detection means for detecting which rotation speed or rotation cycle,
The rotation speed detected by the rotation detection means is a predetermined rotation speed.
When the output of the current sensing means when energized at and the heating means or is equal to or less than the set value, after performed at least once an operation to again turn on once off the switching means, again of the current sensing means Since it has an abnormality detection means for detecting an abnormal state when the output becomes equal to or less than the set value,
When an abnormality occurs in the rotation of the blowing means for controlling the heat generation amount of the heating means, it is detected that the rotation is abnormal, the power supply to the heating means can be stopped, and safety can be improved. Further, when the current value detected by the current detecting means becomes equal to or less than the set value, the operation of turning off and on the opening and closing means is performed at least once, so that the opening and closing means is momentarily shut down by power failure or mechanical vibration. Erroneous detection when the switch is turned off can be prevented.

The apparatus further includes rotation detecting means for detecting the number of rotations or the rotation period of the rotating drum or the motor. The abnormality detecting means detects an abnormal state when the number of rotations detected by the rotation detecting means is equal to or higher than a predetermined number of rotations. Is detected, it is possible to prevent erroneous detection when the current of the heating means decreases due to a decrease in the rotation speed of the rotating drum or the motor.

Further, the heating means and the opening / closing means are respectively divided into a plurality of parts, and the abnormality detecting means turns on the opening / closing means one by one at a predetermined time, and within a predetermined time after all the opening / closing means are turned on. Since the abnormal state is detected when the output of the current detecting means becomes equal to or less than the set value, the heating means is turned on one by one at a predetermined time when the open / close means is once turned off and then turned on again. Rush current can be reduced, and safety can be improved. Further, the abnormality detecting means detects an abnormal state only when the output of the current detecting means becomes equal to or less than the set value within a predetermined time after all of the opening / closing means are turned on. It is possible to prevent erroneous detection when the opening / closing means is turned off due to a power failure, mechanical vibration, or the like.

[Brief description of the 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 an operation flowchart of the clothes dryer.

FIG. 4 is a subroutine flowchart of abnormality detection of the clothes dryer.

FIG. 5 is a subroutine flowchart for controlling the number of revolutions of the clothes dryer.

FIG. 6A is an operation time chart at the start of operation of the clothes dryer. FIG. 6B is an operation time chart at the start of operation of the clothes dryer. d) Operation time chart at the start of operation of the clothes dryer (e) Operation time chart 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 16 current detecting means 20 abnormality detecting means 23 relay (opening / closing means)

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-164595 (JP, A) JP-A-4-152994 (JP, A) JP-A-2-239900 (JP, A) JP-A-60-1985 242900 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) D06F 58/28

Claims (3)

(57) [Claims] 1. A rotating drum for drying clothes, blowing means for circulating warm air into the rotating drum, heating means provided on a blowing path into the rotating drum, and the blowing means
And a motor for rotating the rotary drum, a switching means for controlling said heating means, and current sensing means for sensing the current of the heating means, the rotating drum or the motor
Rotation detection means for detecting the number of rotations or rotation cycle of the motor
And the number of rotations detected by the rotation detecting means is a predetermined number of times.
When the output of the current detecting means becomes equal to or less than a set value when the heating means is energized and the number of rotations is equal to or more than one, an operation of once turning off and on the opening and closing means is performed at least once, and then the current detecting means is turned on again. A clothes dryer provided with abnormality detection means for detecting an abnormal state when the output becomes equal to or less than a set value. 2. The apparatus according to claim 1, further comprising: rotation detection means for detecting a rotation speed or a rotation cycle of the rotating drum or the motor, wherein the abnormality detection means detects an abnormal state when the rotation speed detected by the rotation detection means is equal to or higher than a predetermined rotation speed. The clothes dryer according to claim 1, wherein the clothes dryer is detected. 3. The heating means and the opening / closing means are each divided into a plurality of parts, and the abnormality detecting means turns on the opening / closing means one by one at a predetermined time, and within a predetermined time after all the opening / closing means are turned on. 2. The clothes dryer according to claim 1, wherein an abnormal state is detected when an output of the current detecting means becomes equal to or less than a set value.