JPH06134191A - Clothes drier - Google Patents

Abstract

PURPOSE:To decrease malfunctions and to surely stop a rotary drum when abnormality is generated in the operation of the clothes drier which dries clothes by circulating hot air into the rotary drum to be rotationally driven by a motor. CONSTITUTION:The hot air is circulated by a heat exchange type double winged fan into the rotary drum 1 for drying the clothes. The blast route into the rotary drum 1 is provided with a PTC heater 3. The rotary drum 1 and the heat exchange type double winged fan are rotationally driven by the motor 5. The rotating speed of the rotary drum 1 is detected by a rotation detecting means 7 and the current of the motor 5 is controlled by a rotation control means 9, by which the rotary drum 1 is controlled to the set rotating speed. The rotation of the rotary drum 1 is stopped by an abnormality protecting means 20 when the abnormal state is detected by the output of the rotation detecting means 7. The rotary drum 1 is stopped when the abnormality arises in the rotation of the rotary drum 1; for example, when a belt connecting the motor 5 and the rotary drum 1 slips.

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 have come into widespread use, and it is required to stop the clothes dryer when its operation is abnormal to prevent unevenness in drying or damage of the material to be dried.

Conventionally, this type of clothes dryer is disclosed in Japanese Patent Laid-Open No. 63-63.
It was configured as shown in Japanese Patent No. 181797. That is, the rotation detector detects a decrease in the rotation speed of the rotating drum, outputs an abnormal state signal, and stops the operation.

[0004]

In such a conventional clothes dryer, if the number of rotations of the rotary drum is instantly reduced, an abnormal state signal is output and the operation is stopped, so that many malfunctions occur. Had a problem. In particular, the rotational speed of the rotary drum fluctuates greatly for a few seconds to a few minutes immediately after the start of the drying operation, and the operation is stopped when the rotational speed instantaneously decreases.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and its object is to ensure that the rotary drum is stopped only when there is little malfunction and only when a malfunction occurs.

[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. Heating means provided in the, the air blowing means or a motor for rotationally driving the rotating drum, a rotation detecting means for detecting the number of rotations of the rotating drum, and the motor current is controlled to set the rotating drum to a set number of rotations. A first problem solving means is provided with rotation control means for controlling and abnormality protection means for stopping the rotation of the rotary drum when an abnormal state is detected by the output of the rotation detection means.

Further, the rotation control means of the first problem solving means is provided with a low speed starting means for lowering the set rotational speed at the time of starting the motor, and during the period set by the low speed starting means at the time of starting the rotation of the motor, an abnormality occurs. The second problem solving means is that the protection means is not operated.

In addition to the first means for solving the above problems,
It comprises a current detection means for detecting the current of the heating means, and a current comparison setting means for inputting the output of the current detection means, the rotation control means controls the set rotation speed by the output signal of the current comparison means, The third problem solving means is to set an upper limit value for the set rotation speed so that the current of the heating means does not exceed a predetermined current value.

In addition to the first means for solving the above problems,
The current detection means for detecting the current of the heating means and the current comparison setting means for inputting the output of the current detection means are provided, and the rotation control means controls the set rotation speed by the output signal of the current comparison means, and sets it. The provision of upper and lower limits for the number of revolutions is the fourth means for solving the problem.

The rotation control means of the first problem solving means includes a power semiconductor element connected in series to the motor,
A rotation speed determination means for determining the rotation speed or rotation cycle of the rotary drum based on the output of the rotation detection means, a rotation speed setting means for setting the rotation speed of the rotary drum, an output of the rotation speed determination means, and a rotation speed setting means. Rotation speed comparison means for comparing the output of the, and pulse width control means for controlling the conduction time of the power semiconductor element by the output of the rotation speed comparison means,
A fifth problem solving means is to have a low speed starting means for lowering the set rotation speed when the motor is started.

Further, the abnormality protection means of the first problem solving means outputs an abnormal state when the rotation speed detected by the rotation detection means is lower than the lower limit value of the rotation speed set by the rotation control means. This is the sixth means for solving problems.

[0012]

According to the first means for solving the above problems, the present invention provides:
When an abnormality occurs in the rotation of the rotating drum such as when the belt connecting the motor and the rotating drum slips, the rotating drum can be stopped and safety can be improved.

Further, according to the second means for solving the problem, the rotation speed of the motor at the time of starting is reduced to reduce the circulating air volume,
It is possible to reduce the rush current flowing through the heating means composed of a C heater or the like and to stably start it up. Moreover, while the rotation speed at the time of starting is low, the abnormal protection means does not operate and malfunctions can be prevented. .

Further, by the third means for solving the problems, it is possible to prevent an excessive current from flowing through the PTC heater due to an increase in the air volume, and to prevent an increase in noise due to an increase in the rotation speed.

Further, the fourth problem solving means prevents an excessive current from flowing through the PTC heater due to an increase in the air volume, and prevents an increase in noise due to an increase in the number of revolutions. As a result of the reduced air flow, the current flowing through the PTC heater is reduced, and it is possible to prevent the drying time from increasing.

Further, by the fifth problem solving means, the number of rotations of the rotary drum can be controlled to the number of rotations set by the number of rotations setting means, the amount of circulating air is reduced at the time of starting, and the inrush current flowing to the PTC heater is reduced. , Can be stably started.

Further, according to the sixth problem solving means, the rotating drum can be stopped when the rotating speed of the rotating drum cannot be controlled to the rotating speed set by the rotating speed setting means, and the belt connecting the motor and the rotating drum. The rotating drum can be stopped when the number of rotations of the rotating drum decreases, such as when the rotating drum slips.

[0018]

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, the 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 ventilation 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, etc., the amount of air blown decreases, the heating power of the PTC heater 3 decreases, and the drying time becomes longer and the drying efficiency also decreases. The motor 5 rotationally drives 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 generated by the heater 3 can be controlled, and the current can be controlled. The temperature detecting means 6 detects the temperature of the air sucked into the PTC heater 3. The rotation detecting means 7 is the rotating drum 1.
The rotation speed of the magnet 8 is detected.
3 to 6 are attached and a magnetic sensor (not shown) is fixed to the main body to detect the number of rotations of the rotary drum 1.

The rotation control means 9 controls the rotation speed of the motor 5. The power semiconductor element 10 such as a bidirectional thyristor connected in series to the motor 5 and the rotation detection means 7 output the rotation of the rotary drum 1. Rotation speed determination means 11 for determining the number of rotations, rotation speed setting means 12 for setting the rotation speed of the rotary drum 1, and rotation speed comparison means for comparing the output of the rotation speed determination means 11 and the output of the rotation speed setting means 12. 13, pulse width control means 14 for controlling the conduction time of the power semiconductor element 10 by the output of the rotation speed comparison means 13, and the motor 5
And a low-speed starting means 15 for lowering the set rotation speed at the time of starting, and 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 calculated as the rotation speed. The comparison is performed by the comparison means 13, and the pulse width control means 14 controls the power semiconductor element 10 to control the rotation speed of the motor 5. 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. If you do this,
Stable rotation control of the motor 5 and the rotary drum 1 can be performed. The low speed starting means 15 controls the rotation speed setting means 12 for a predetermined time (for example, 20 seconds) when the motor 5 is started, and the rotation speed is low (36 rpm) with respect to the rotation speed (45 rpm) of the rotary drum 1 during normal operation. ). Further, the rotation speed determination means 11 may determine the rotation cycle of the rotary drum 1 from the output of the rotation detection means 7.

The current detecting means 16 is the current transformer 1.
7 and the current-voltage conversion circuit 18, detects the input current of the PTC heater 3, and outputs the output from the current comparison setting means 1.
Enter in 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 rotation speed set by the rotation speed setting means 12 is set so that the current of the PTC heater 3 does not exceed or fall below a predetermined current value.

The abnormality protection means 20 is composed of a rotation stopping means 21 and an informing means 22, inputs the output of the rotation number judging means 11, and when the rotation number judging means 11 detects the rotation abnormality of the rotary drum 1, The rotation stopping means 21 turns off the switch 23 to stop the rotation of the rotary drum 1, and at the same time, the notifying means 22 gives a notification. Further, the low speed starting means 15 lowers the abnormality determination value or does not operate during the period in which the rotation speed of the rotary drum 1 is set low when the motor 5 is started. AC power supply 24 is PT
Relay contacts 25a and 25b are connected in series to the C heaters 3a and 3b, respectively.

The operation of the above configuration will be described with reference to FIGS. 3 and 4. FIG. 3 is an operation flowchart of an embodiment of the present invention. The operation is started at step 30, initialized at step 31, and then step 32. Then, the motor 5 is turned on, and the heater 3 is turned on at step 33. Step 34
Then, the low-speed starting means 15 sets the rotation speed setting means 12 to a low speed (36 rpm), and the rotation detecting means 7
The rotation speed comparison means 13 compares the difference between the rotation speed of the rotary drum 1 and the rotation speed set by the rotation speed setting means 12, and the pulse width control means 14 controls the power semiconductor element 10 to control the motor 5. Control the rotation speed to a low speed.
Therefore, the amount of air circulated to the rotary drum 1 is small, and the inrush current flowing through the heater 3 can be suppressed to be small. At this time, the abnormality protection means 20 keeps the abnormality determination value low, so that the abnormality protection means 20 does not operate. When the predetermined time (20 seconds) has elapsed, the process proceeds to step 35.

In step 35, the rotation speed of the rotary drum 1 is controlled to a normal rotation speed (for example, 45 rpm). The details of the operation at this time will be described with reference to FIG.
Set the 1-second timer in step 51, then step 52
At step 53, the current is detected by the current detecting means 16.
Then, the current comparison setting means 19 calculates an error from the current setting value. This calculation result is input to the rotation speed setting means 12,
In step 54, the rotation cycle of the rotary drum 1 is calculated and set based on the calculation result. Then, the cycle Ts calculated and set in step 55 is compared with the maximum cycle Tsmax, and if the cycle Ts is larger than the maximum cycle Tsmax, the routine proceeds to step 56, where the maximum cycle Tsmax is set. When the cycle Ts is smaller than the maximum cycle Tsmax, the routine proceeds to step 57, where the calculated cycle Ts is compared with the minimum cycle Tsmin, and the cycle Ts is the minimum cycle Tsm.
When it is smaller than in, the process proceeds to step 58 and the minimum period Tsm
The process proceeds to step 59 with in as the set cycle. If the period Ts is larger than the minimum period Tsmin, the process proceeds to step 59. Therefore, the set cycle Ts set by the rotation speed setting means 12 is smaller than the maximum cycle Tsmax and the minimum cycle Tsmin.
It is set larger.

In step 59, it is determined whether or not the rotation detection signal is input from the rotation detection means 7. If the rotation detection signal is input, in step 60 the rotation cycle T
Is detected and the process proceeds to step 61. In step 61, the rotation speed comparison means 13 detects an error from the set cycle Ts and proceeds to step 62 to determine whether the detected error is within the set range. If it is within the set range, the next step (step of FIG. 3). Proceed to 36). If the detected error is not within the set range, the process proceeds to step 63, 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. In step 59, if the rotation detecting signal is not input from the rotation detecting means 7, the process proceeds to the next step.

In step 36 of FIG. 3, it is determined whether or not the detected rotation cycle T is larger than a cycle Tab (for example, 30 rpm at the rotation speed of the rotary drum 1) which is determined to be in an abnormal state, and the rotation cycle T is abnormal cycle Tab. When it is smaller, the process proceeds to step 39 through steps 37 and 38, and steps 35 to 39 are repeated. When the dry collection is carried out in step 39, the operation ends. When the rotation period T is larger than the abnormal period Tab in step 36, the process proceeds to step 39 through steps 40 and 38, and steps 35 to 39 are repeated. When this repetition is repeated 16 times, the process proceeds to step 41 and the rotation stop means 21 is used. The switch 23 is turned off and stopped, and the notification means 22 notifies the abnormality.

As described above, according to this embodiment, the rotation detecting means 7 for detecting the rotation speed of the rotary drum 1, and the rotation control means for controlling the electric current of the motor 5 to control the rotation drum 1 to the set rotation speed. 9 and an abnormality protection unit 20 that stops the rotation of the rotary drum 1 when an abnormal state is detected by the output of the rotation detection unit 7, and the rotation control unit 9 includes a power semiconductor element 10 connected in series to the motor 5. , Rotation detection means 7
Output of the rotational drum 1 for determining the rotational speed or rotational period of the rotating drum 1, rotational speed setting means 12 for setting the rotational speed of the rotating drum 1, output of the rotational speed determination means 11, and rotational speed setting means. The rotation speed comparison means 13 for comparing with the output of 12, the pulse width control means 14 for controlling the conduction time of the power semiconductor element 10 by the output of the rotation speed comparison means 13, and the set rotation speed when the motor 5 is started. Since the low-speed starting means 15 is provided, the motor 5 and the rotary drum 1
When an abnormality occurs in the rotation of the rotating drum 1 such as when a belt connecting between the rotating drum 1 and the rotating drum 1 slips, the rotating drum 1 can be stopped and safety can be improved. Further, the amount of circulating air can be reduced at the time of startup, the rush current flowing through the PTC heater 3 can be reduced, and stable startup can be achieved.

In the above embodiment, the case where the rotating drum 1 and the heat exchanging type double-blade fan 2 are driven by one motor 5 has been described, but the same effect can be obtained by using two motors each. is there.

[0029]

As is apparent from the above embodiments, according to the present invention, 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. Heating means provided in the, the air blowing means or a motor for rotationally driving the rotating drum, a rotation detecting means for detecting the number of rotations of the rotating drum, and the motor current is controlled to set the rotating drum to a set number of rotations. Since the rotation control means for controlling and the abnormality protection means for stopping the rotation of the rotating drum when an abnormal state is detected by the output of the rotation detecting means are provided, the belt connecting the motor and the rotating drum slips. When an abnormality occurs in the rotation of the rotating drum, the rotating drum can be stopped and safety can be improved.

Further, the rotation control means includes low speed starting means for lowering the set rotational speed at the time of starting the motor, and during the period set by the low speed starting means at the time of starting the rotation of the motor,
Since the abnormality protection means is not operated, the rotation speed of the motor at the time of startup is reduced to reduce the amount of circulating air, the inrush current flowing to the PTC heater is reduced, and stable startup is possible. While the rotational speed is low, the abnormality protection means does not operate, and malfunctions can be prevented.

Further, it comprises current detection means for detecting the current of the heating means and current comparison setting means for inputting the output of the current detection means, and the rotation control means is set by the output signal of the current comparison means. Is controlled so that the current of the heating means does not exceed a predetermined current value, the set rotational speed is set to an upper limit value. Therefore, an excessive current does not flow to the PTC heater due to an increase in the air flow, and the rotational speed is also increased. It is possible to prevent the noise from becoming loud due to the increase in.

Further, it comprises current detection means for detecting the current of the heating means, and current comparison setting means for inputting the output of the current detection means, and the rotation control means is set by the output signal of the current comparison means. Since the upper and lower limit values are set for the set rotation speed, an excessive current does not flow to the PTC heater due to an increase in the air volume, and noise can be prevented from increasing due to the increase in the rotation speed. Further, it is possible to prevent the current flowing through the PTC heater from decreasing due to the decrease in the air volume, which can prevent the drying time from increasing.

The rotation control means includes a power semiconductor element connected in series to the motor, a rotation speed determination means for determining the rotation speed or rotation cycle of the rotary drum based on the output of the rotation detection means, and the rotation speed of the rotary drum. And a rotation speed comparison means for comparing the output of the rotation speed determination means and the output of the rotation speed setting means, and the conduction time of the power semiconductor element is controlled by the output of the rotation speed comparison means. Since the pulse width control means for controlling the rotation speed and the low speed starting means for lowering the set rotation speed at the time of starting the motor are provided, the rotation speed of the rotating drum can be controlled to the rotation speed set by the rotation speed setting means, and the circulating air volume is reduced at the time of start. , The inrush current flowing through the PTC heater can be reduced, and the PTC heater can be stably activated.

Further, since the abnormality protection means outputs an abnormal state when the rotation speed detected by the rotation detection means is lower than the lower limit value of the rotation speed set by the rotation control means, the rotation speed of the rotating drum is changed to the rotation speed. The rotating drum can be stopped when the number of rotations set by the setting means cannot be controlled, and the rotating drum is stopped when an abnormality occurs in the rotation of the rotating drum such as when a belt connecting the motor and the rotating drum slips. be able to.

[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 an operation flowchart of the clothes dryer.

FIG. 4 is a subroutine flowchart of the rotation speed control of the clothes dryer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 rotating drum 2 heat exchange type double-blade fan (blowing means) 3 PTC heater (heating means) 5 motor 7 rotation detection means 9 rotation control means 20 abnormal protection means

Claims (6)

[Claims] 1. A rotary drum for drying clothes, a blower for circulating warm air into the rotary drum, a heating means provided in a blower path into the rotary drum, and the blower or the rotary drum. A motor driven to rotate, a rotation detecting means for detecting the number of rotations of the rotating drum, a rotation control means for controlling the motor current to control the rotating drum to a set number of rotations, and an abnormality due to an output of the rotation detecting means. A clothes dryer having an abnormality protection means for stopping the rotation of the rotary drum when a state is detected. 2. The rotation control means is provided with a low speed starting means for lowering the set rotational speed when the motor is started, and the abnormality protection means is not operated during the period set by the low speed starting means when the motor is started to rotate. The clothes dryer according to claim 1. 3. A current detection means for detecting the current of the heating means, and a current comparison setting means for inputting the output of the current detection means, wherein the rotation control means sets the number of rotations by an output signal of the current comparison means. 2. The clothes dryer according to claim 1, wherein an upper limit value is set for the set rotation speed so that the current of the heating means does not exceed a predetermined current value. 4. A current detection means for detecting the current of the heating means, and a current comparison setting means for inputting the output of the current detection means, wherein the rotation control means sets the number of rotations according to the output signal of the current comparison means. 2. The clothes dryer according to claim 1, wherein the upper limit and the lower limit are set for the set rotation speed. 5. The rotation control means includes a power semiconductor element connected in series to the motor, a rotation speed determination means for determining the rotation speed or rotation cycle of the rotary drum based on the output of the rotation detection means, and the rotation speed of the rotary drum. And a rotation speed comparison means for comparing the output of the rotation speed determination means and the output of the rotation speed setting means, and the conduction time of the power semiconductor element is controlled by the output of the rotation speed comparison means. 2. The clothes dryer according to claim 1, further comprising pulse width control means for controlling the rotation speed, and low speed starting means for reducing the set rotation speed when the motor is started. 6. The clothes dryer according to claim 1, wherein the abnormality protection means outputs an abnormal state when the rotation speed detected by the rotation detection means is lower than the lower limit value of the rotation speed set by the rotation control means.