JP3254842B2 - 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
-64293. That is, the current of the positive temperature characteristic heater (PTC heater) is detected, and an abnormality is detected when the heater current increases or decreases as compared with each set current of the air blowing operation or the heating operation.

[0004]

In such a conventional clothes dryer, it is not possible to discriminate between the case where the rotation of the blower fan stops and the case where the energization control means has an open failure. And had the problem of spending time on its repair. In particular, there is a problem that it is not possible to distinguish between a failure of the motor that rotationally drives the blower fan or a failure of the fan belt for transmitting the rotation of the motor and a failure of the power supply control means such as the relay.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and it is an object of the present invention to detect a malfunction without fail in the operation of an opening / closing means of a heating means and to clearly notify the details of the malfunction. .

[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. Heating means, a motor for rotating the blowing means or the rotating drum, an opening / closing means for controlling the heating means, a current detection means for detecting a current of the heating means, and a power supply for the heating means. When the output of the current detecting means is equal to or less than a set value, the operation of turning off and on the opening means is performed at least once, and then the output of the current detecting means is equal to or less than the set value again. wherein the first abnormality detecting means for detecting the abnormal state of the blower means, the output changes from the second abnormality detection to detect an abnormal condition of said switching means of said current detecting means at the time of opening and closing operation of said opening and closing means And means, the first abnormality detection period in which detect an abnormal condition in means, said second abnormality detection means has a first means for solving problems that it has not to operate.

After the start of operation, the first abnormality detecting means
If the second abnormality detection unit determines that the operation is normal at least once before the operation, the second abnormality detection unit does not operate thereafter, and only the first abnormality detection unit operates. This is the second means for solving the problem.

[0008]

According to the first aspect of the present invention, there is provided:
It is possible to individually detect when an abnormality occurs in the rotation of the blowing means that controls the amount of heat generated by the heating means, and when an abnormality occurs in the opening and closing means that controls the heating means. During the period when an abnormality occurs and the opening / closing means is once turned off and then turned on again, the abnormality of the opening / closing means for controlling the heating means is not detected, so that the abnormality relating to the rotation of the blowing means and the opening / closing means for controlling the heating means are not detected. Abnormalities can be accurately distinguished and detected.

Further, according to the second problem solving means, if it is determined that the opening / closing means for controlling the heating means is operating normally once after the start of the operation, no abnormality of the opening / closing means is detected thereafter. In addition, the abnormality detection program can be simplified, and the details of the abnormality detected differ depending on the time from the start of operation, so that the details of the abnormality can be easily distinguished.

[0010]

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, a rotating drum 1 is for storing and drying an object to be dried (clothing), and hot air is circulated 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 PTC heater 3 can be controlled, and current control can be performed. Temperature detecting means 6a and 6
"b" is for detecting the air temperature before and after the heat exchange by the heat exchange type double-blade fan 2, respectively.

The control means 7 includes a relay (opening / closing means) 8 for controlling the power supply to the PTC heater 3, a current detection circuit comprising a current transformer 10 and a current-voltage conversion circuit 11 for detecting the current of the PTC heater 3. It comprises a means 9, a first abnormality detecting means 12a and a second abnormality detecting means 12b for detecting an abnormal state from an output signal of the current detecting means 9, and a notifying means 13 for notifying an abnormality by light or sound. .

The first abnormality detecting means 12a performs at least one operation of turning off the relay 8 once and turning it on again when the output of the current detecting means 9 becomes lower than the set value when the PTC heater 3 is energized. Thereafter, when the output of the current detecting means 9 falls below the set value again, the abnormal state is detected. Further, the second abnormality detecting means 12b detects an abnormal state from a change in the output of the current detecting means 9 during the opening / closing operation of the relay 8, and detects the abnormal state with the first abnormality detecting means 12a. Is the second abnormality detection means 12
b does not operate.

When an abnormality is detected by the first abnormality detecting means 12a or the second abnormality detecting means 12b, the abnormality is notified by the notifying means 13 and the energization of the motor 5 is stopped by the motor control means 14. Like that. The power supply opening / closing means 15 is connected in series to the PTC heater 3 or the motor control means 14, and controls energization from the AC power supply 16. The PTC heater 3 includes a plurality of heaters 3
a, 3b, each of which has a relay 8a, 8b
b are connected in series.

The operation of the above configuration will be described with reference to FIG. 3. FIG. 3 is an operation flowchart of one embodiment of the present invention. In step 30, a power switch is turned on to start operation. After initial setting in step 31, step 32
To energize the motor 5 to rotate the rotating drum 1 and the blowing means 2. In step 33, a relay open abnormality detection process is performed by the second abnormality detection means 12b. The relay open abnormality detection processing will be described later. If the abnormality F = 1 in step 34, the process proceeds to step 35, in which the notification means 13 notifies the relay open abnormality, and in steps 36 and 37, the PTC heater 3 is controlled by controlling the relay 8 and the motor control means 14 for safety. And the energization of the motor 5 is stopped. If the abnormality F = 0 in step 34, the subsequent relay open abnormality detection is stopped in step 38.

Next, at step 39, the first abnormality detecting means 12a performs a fan belt breakage abnormality detecting process, and at step 40, it is determined whether or not the drying is completed.
If it has been completed, the drying operation is ended in step 41. If not, the process returns to step 39. The fan belt outage abnormality detection processing will be described later.

Next, the relay open abnormality detection processing by the second abnormality detection means 12b will be described with reference to FIG. 4. First, a delay time of 20 seconds is provided in step 50, and in step 51, the current detection means 9 The current I0 of the PTC heater 3 is detected. Relay 8 in step 52
A is closed to energize the PTC heater 3a, and the current I1 is detected by the current detecting means 9 in step 53. The current I1 is detected approximately three seconds after the relay 8a is closed. Step 54 is for detecting a change in the current of the PTC heater 3 when the relay 8a is closed, and is determined from the difference between the current I1 and the current I0. Step 55 is to compare the current change (I1-I0) with the set value.
It can be determined that the current has increased due to the current being supplied to the device, and it is normal. If the current change (I1-I0) is small, it is determined that the relay 8a has an open failure, and the routine proceeds to step 63, where the abnormality F = 1 is set.

Next, if the relay 8a is normal in step 55, after a delay time of 30 seconds in step 56, the current I2 of the PTC heater 3 is detected in step 57. Thereafter, in step 58, the relay 8b is closed, and the PTC heater current I3 is detected three seconds after the relay 8b is closed in the same manner as in step 53. Then, in step 60, the current change (I3-I2) is calculated, and in step 61, the current change (I3-I2) is calculated.
If 3-I2) is equal to or larger than the set value, it is determined that the operation is normal and step 62
Proceed to and set the abnormality F = 0. If it is equal to or less than the set value, it is determined that the relay 8b has an open failure, and the routine proceeds to step 63, where an abnormality F = 1 is set.

Next, a description will be given of the fan belt breakage abnormality detection processing by the first abnormality detection means 12a with reference to FIG. 5. In step 70, it is determined 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 the value is less than the set value Is, the process proceeds to step 71 and the PTC
The heaters 3a and 3b are once turned off, and then, at step 72, 1.5
Delay for seconds. From step 73 to step 75,
20 seconds after turning on the PTC heater 3a, the PTC
The heater 3b turns on.

Then, in step 76, the timer 1 is cleared, and in steps 77 and 78, the timer 1
It is determined again whether the current of the PTC heater 3 is smaller than the set value Is until 0 seconds have elapsed. Set value I within 60 seconds
If not, proceed to the next step. If the value is less than the set value Is within 60 seconds, the process proceeds to step 79 to detect an abnormality of the fan belt and notify the abnormality by the notifying means 13, and turns off the PTC heater 3 in step 80 and turns off the motor 5 in step 81. I do.

FIGS. 6A to 6C show a change in the current of the PTC heater 3 when the relay 8 is controlled to be conductive.
Is P when the relay 8 and the heat exchange type double wing fan 2 are normal.
The current of the TC heater 3 is shown. FIG. 6B shows a case where the relay 8 is normal and the blower 2 is stopped. When the relay 8 is closed, an inrush current flows through the PTC heater 3 even if the heat exchange type double-blade fan 2 fails, so that energization can be detected by a change in current before and after the relay 8 is closed.
FIG. 6C shows a change in current when the relay 8a has an open failure and the heat exchange type double-wing fan 2 is normal. When the relay 8 has an open failure, there is no change in current, so that the failure can be reliably detected.

In each of the above embodiments, the open failure of the relay 8 is detected only once at the beginning of operation.
The same can be detected when the operation is stopped and then restarted, or when the relay 8 is turned on and off so that the temperature in the rotating drum 1 does not exceed a predetermined value.

Although the relays 8 are sequentially closed to check for an open fault, a short-circuit fault can be similarly detected. It is clear that the same detection can be performed when the relays 8 are sequentially opened.

[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 Heating means, a motor for rotating the blower means or the rotating drum, an opening / closing means for controlling the heating means, a current detection means for detecting a current of the heating means, and when the heating means is energized. When the output of the current detecting means becomes equal to or less than the set value, the operation of turning off and on the opening means is performed at least once, and then the output of the current detecting means becomes equal to or less than the set value again. a first abnormality detection means for detecting the abnormal state of the blower means, and a second abnormality detection means for detecting an abnormal state of the switching means from the output variation of the current sensing means during opening and closing operation of said switching means During the period in which the first abnormality detecting means detects an abnormal state, the second abnormality detecting means is not operated, so that there is an abnormality in the rotation of the blowing means for controlling the heat generation amount of the heating means. It is possible to individually detect the case where the occurrence has occurred and the case where an abnormality has occurred in the opening / closing means that controls the heating means. During the period when the rotation of the blower means is abnormal and the opening / closing means is once turned off and turned on again,
Since the abnormality of the opening / closing means for controlling the heating means is not detected, the abnormality relating to the rotation of the blowing means and the abnormality of the opening / closing means for controlling the heating means can be accurately distinguished and detected.

After the start of operation, the first abnormality detecting means
If the second abnormality detection means determines that the operation is normal at least once before the operation, the second abnormality detection means is not operated thereafter, and only the first abnormality detection means is operated. Therefore, once it is determined that the opening / closing means for controlling the heating means is operating normally after the start of operation, the abnormality of the opening / closing means can be prevented from being detected thereafter, so that the abnormality detection program can be simplified. In addition, since the details of the abnormality to be detected differ depending on the time from the start of operation, it is easy to distinguish the details of the abnormality.

[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 flowchart of a relay open abnormality detection subroutine of the clothes dryer.

FIG. 5 is a flowchart of a fan belt out-of-abnormality detection subroutine of the clothes dryer.

FIG. 6A is a diagram showing a time change of current when the opening / closing means of the clothes dryer is closed. FIG. 6B is a diagram showing a time change of current when the opening / closing means of the clothes dryer is closed. ) A diagram showing the time change of the current when the opening / closing means of the clothes dryer is closed.

[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 control means 8 relay (opening / closing means) 9 current detecting means 12a first abnormality detecting means 12b second abnormality detecting means

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-61-64293 (JP, A) JP-A-61-164595 (JP, A) JP-A-4-152994 (JP, A) JP-A-7-64 59994 (JP, A) JP-A-6-218195 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) D06F 58/02 D06F 58/28

Claims (2)

(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 or the rotating drum. A motor that is rotationally driven, an opening / closing unit that controls the heating unit, a current detection unit that detects a current of the heating unit, and an output of the current detection unit that is equal to or less than a set value when the heating unit is energized, At least one operation of turning the opening / closing means off and on again
After the first time, when the output of the current detecting means again becomes equal to or less than the set value, a first state for detecting an abnormal state of the blowing means is detected.
Abnormality detecting means, and second abnormality detecting means for detecting an abnormal state of the opening / closing means based on a change in output of the current detecting means at the time of opening / closing operation of the opening / closing means. A clothes dryer in which the second abnormality detecting means is not operated during the period of detecting the state. 2. After the start of operation, the first abnormality detecting means operates.
If the second abnormality detecting means determines that the operation is normal at least once before the operation, the second abnormality detecting means is not operated thereafter, and only the first abnormality detecting means is operated. Item 2. The clothes dryer according to Item 1.