JP6832084B2 - Clothes dryer - Google Patents

Description

The present invention relates to a clothes dryer in which an object to be dried such as clothes is housed in a rotating drum and dried.

Conventionally, a clothes dryer is configured to stop rotating a rotating drum when a door is opened during a drying operation (Patent Document 1). Such a clothes dryer includes a motor drive circuit that energizes and de-energizes a rotating drum drum drive motor by turning on and off a relay that is a switching element, a door open / close detection circuit that detects the opening / closing of a door by a door switch, and a door open / close detection circuit. It is equipped with a control unit that electrically connects the motor drive circuit and the door open / close detection circuit, and the control unit turns off the relay of the motor drive circuit when it receives a detection signal that the door has opened from the door open / close detection circuit. To control. As a result, when the door is opened during the drying operation, the energized state of the drum drive motor is de-energized, the drum drive motor is driven and stopped, and the rotating drum is stopped rotating.

Japanese Unexamined Patent Publication No. 6-126100

However, if the relay of the motor drive circuit is held in the ON state and a short-circuit failure (ON failure) that cannot be turned off occurs, the energization of the drum drive motor is maintained even if the control unit outputs a command signal to turn off the relay. There is a problem that the drum drive motor does not stop driving and the rotating drum continues to rotate even when the door is open. In this case, the drum drive motor could not be stopped and the rotating drum could not be stopped unless the power plug of the clothes dryer was pulled out from the outlet to forcibly disconnect the clothes dryer from the AC power supply. ..

The present invention has been made in view of the above circumstances, and provides a clothes dryer capable of stopping the rotation of a rotating drum by opening a door even when a switching element such as a relay of a motor drive circuit has a short failure. The purpose is to do.

The clothes dryer according to the present invention
A rotating drum that houses the object to be dried,
A door that opens and closes the outlet for the object to be dried on the rotating drum,
A drum drive motor that rotates and drives a rotating drum,
A motor drive circuit that turns on and off the switching element to energize and de-energize the drum drive motor ,
A gas burner that generates combustion exhaust gas to be sent into the rotating drum, and a burner unit that has a valve device for supplying fuel gas to the gas burner.
Equipped with a control unit that connects to the motor drive circuit
The motor drive circuit electrically connects a door switch that turns on and off in conjunction with the opening and closing of the door in the circuit, shuts off the energization of the drum drive motor when the door opens and the door switch turns off, and energizes the drum drive motor. The circuit configuration is such that the cutoff state is transmitted to the control unit.
The control unit recognizes the drive stop of the drum drive motor when the switching element or the door switch is turned off and the energization of the drum drive motor in the motor drive circuit is cut off, and is linked to the drive stop of the drum drive motor. The valve device of the burner unit is controlled to be closed .

As a result, by opening the door, the energization of the drum drive motor can be cut off in the motor drive circuit, and the drum drive motor can be driven and stopped. Therefore, even if a switching element such as a relay fails (ON failure), when the door is opened, the drum drive motor stops driving and the rotating drum stops rotating, so that the rotating drum continues to rotate with the door open. Never. Then, when the door is closed, the door switch is turned on and the power cutoff of the drum drive motor is released, so that the rotating drum can be rotated again.
Further, conventionally, a door open / close detection circuit including a door switch and a motor drive circuit are separately provided in order to stop the rotation of the rotating drum when the door is opened. However, according to the above configuration, the motor drive circuit is provided. The circuit configuration can be configured to have the function of the door open / close detection circuit, and it is not necessary to separately provide the door open / close detection circuit. Therefore, the configuration of the entire circuit can be simplified.

Further , the control unit can recognize the drive stop of the drum drive motor due to the door opening due to the output from the motor drive circuit. Then, when the control unit recognizes that the drum drive motor has stopped driving due to the opening of the door, the control unit closes the valve device of the burner unit. As a result, the gas burner is extinguished, and the combustion exhaust gas from the burner unit is not sent into the rotating drum in the stopped rotation state or leaked from the outlet with the door open. Therefore, it is necessary to avoid a situation in which a part of the object to be dried in the rotating drum that has stopped rotating is overheated and damaged, or the user standing in front of the outlet with the door open is exposed to the hot air of the combustion exhaust gas. Can be done. Further, the combustion exhaust gas does not stay around the burner unit and a part of the clothes dryer is not overheated.

According to the present invention, even if a switching element such as a relay fails due to a short circuit, the drum drive motor can be stopped by opening the door. Therefore, it is possible to prevent an unexpected situation in which the rotating drum stops rotating by opening the door without pulling out the power plug of the clothes dryer from the outlet, and the rotating drum continues to rotate with the door open.

It is sectional drawing which shows the structure of the clothes dryer which concerns on embodiment. It is an electric circuit diagram of the motor drive circuit in the clothes dryer which concerns on embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
As shown in FIG. 1, the clothes dryer 1 is composed of a rectangular box-shaped main body case 10 and a door 12 that opens and closes a clothes outlet 11 that opens in front of the main body case 10. In this specification, the front surface of the main body case 10 is the front surface of the clothes dryer 1, and the depth direction of the main body case 10 is the front-rear direction, the width direction is the left-right direction, and the height direction is the height direction when the clothes dryer 1 is viewed from the front. It is called the vertical direction.

Inside the main body case 10, a cylindrical rotary drum 2 for accommodating clothing C as an object to be dried, air supply from the outside of the main body case 10 into the rotary drum 2, and an exhaust duct 13 from the inside of the rotary drum 2 are passed through the main body. The air supply / exhaust fan 14 that exhausts air to the outside of the case 10, the drum drive motor 3 that rotationally drives the rotary drum 2 via the belt 2a, and the drum drive motor 3 that rotationally drives the air supply / exhaust fan 14 via the belt 14a, and the inside of the rotary drum 2. It is provided with a burner unit 4 that generates warm air for drying the clothes C.

The burner unit 4 has a gas burner 41 that generates combustion exhaust gas, and a valve device 43 for supplying fuel gas to the gas burner 41 through a gas supply pipe 42. The valve device 43 is provided with a first solenoid valve 43a, a second solenoid valve 43b, and a proportional valve 43c. The burner unit 4 is connected to a hot air duct 15 that introduces the combustion exhaust gas of the gas burner 41 into the rotating drum 2 as hot air together with air.

The hot air duct 15 is provided with an ignition electrode 41a for igniting the gas burner 41 and a thermocouple 41b for detecting a misfire, and a first overheat switch composed of a thermocouple 15a and a bimetal switch to prevent overheating. A 15b and a thermal fuse 15c are provided, and a blowout temperature sensor 15d for detecting the temperature of the hot air supplied to the rotating drum 2 is provided. The exhaust duct 13 is provided with an exhaust temperature sensor 13a for detecting the exhaust temperature for determining the end of the drying operation and a second overheat switch 13b for detecting an abnormality in the exhaust temperature.

The clothes dryer 1 having the above configuration sends warm air heated by the gas burner 41 into the rotating rotating drum 2, and blows air containing water vapor from the clothes C housed in the rotating drum 2 to the outside of the machine. By discharging the clothes C, the clothes C are dried.

Further, the clothes dryer 1 is configured to detect the opening and closing of the door 12 and stop the rotation of the rotating drum 2 when the door 12 is open. This configuration is executed by a motor drive circuit 6 that drives and controls the drum drive motor 3. The motor drive circuit 6 energizes and de-energizes the drum drive motor 3 by turning on and off the switching element, and its electronic board is incorporated in the controller 5. The controller 5 is provided with a microcomputer (control unit) 51 for controlling each unit.

With reference to FIG. 2, the electrical configuration of the motor drive circuit 6 includes a series circuit 61 in which the drum drive motor 3 is connected in series with the relay switch 71 of the relay 7 serving as a switching element, and both ends of the series circuit 61. The contacts 61a and 61b are configured to be connected to the pair of AC bus 8a and 8b of the AC power supply 8, respectively. The AC power supply 8 is, for example, a commercial power supply of 100 V, and the power plug of the clothes dryer 1 is inserted into the outlet of the commercial power supply to supply power to the circuit.

The drive coil (not shown) of the relay 7 is connected to the output terminal 51a of the microcomputer 51, and the relay 7 relays when the drive coil is excited by the relay drive signal (command signal) from the microcomputer 51. When the switch 71 is turned on and the drive coil is demagnetized, the relay switch 71 is controlled to be turned off. When the relay switch 71 of the relay 7 which is a switching element is turned on, the drum drive motor 3 is in a state where it can be energized with the AC power supply 8. Therefore, when the relay switch 71 is turned on by the relay drive signal of the microcomputer 51 and the AC power supply 8 is energized to the drum drive motor 3, the drum drive motor 3 is driven and the rotary drum 2 is rotated. When the relay switch 71 is turned off by the relay drive signal of the microcomputer 51 and the AC power supply 8 is not energized to the drum drive motor 3, the drum drive motor 3 is driven and stopped, and the rotating drum 2 is stopped rotating. The switching element is not limited to the relay 7, and a semiconductor element such as a triac may be used.

Further, in the motor drive circuit 6, a door switch 16 that turns on and off in conjunction with the opening and closing of the door 12 is connected in series to the AC bus 8a, which is one of the energizing paths from the AC power supply 8 to the drum drive motor 3. .. The connection position of the door switch 16 may be connected in series in the circuit of the path through which the current of the AC power supply 8 flows to the drum drive motor 3, and is, for example, an energizing path from the AC power supply 8 to the relay 7. The other AC bus 8b, the drum drive motor 3 and the relay 7 may be connected in series to the series circuit 61 or the like.

The door switch 16 is composed of, for example, a micro switch, the micro switch is attached to the front side (see FIG. 1) of the main body case 10, and a pin 16a projecting rearward is provided on the back surface of the door 12 to close the door 12. And this pin 16a presses the working piece of the microswitch to turn on the microswitch, and when the door 12 is opened, the pin 16a separates from the working piece and turns off the microswitch. The door switch 16 is not limited to the micro switch, and various detection means such as a photoelectric sensor and a magnetic sensor may be used.

In the motor drive circuit 6, when the door 12 is closed and the door switch 16 is turned on, the current-carrying path between the AC power supply 8 and the drum drive motor 3 is connected, and the AC power supply 8 can be energized to the drum drive motor 3. On the other hand, when the door 12 is opened and the door switch 16 is turned off, the current-carrying path between the AC power supply 8 and the drum drive motor 3 is cut off so that the drum drive motor 3 is cut off from the AC power supply 8. It is configured.

Therefore, according to the motor drive circuit 6, the AC power supply 8 is energized to the drum drive motor 3 when both the door switch 16 and the relay switch 71 are in the ON state. Therefore, when the relay switch 71 is turned on by the relay drive signal (relay on command signal) from the microcomputer 51 on the condition that the door 12 is closed, the drum drive motor 3 is driven and the rotary drum 2 is rotated. It will be. When the door 12 is open, the door switch 16 cuts off the energization of the drum drive motor 3 in the motor drive circuit 6, so that the drum drive is performed regardless of the relay drive signal (relay off command signal) from the microcomputer 51. The motor 3 is not driven and the rotating drum 2 does not rotate. For example, when the door 12 is opened during the drying operation, the drum drive motor 3 is driven and stopped, and the rotating drum 2 is stopped rotating.

By the way, a configuration in which the rotating drum 2 is stopped rotating when the door 12 is opened during a drying operation or the like has been conventionally known, but as a conventional control configuration, a door open / close detection circuit including a door switch 16 is an input of a microcomputer 51. It is connected to a terminal, a motor drive circuit including a drum drive motor 3 and a relay 7 is connected to an output terminal of the microcomputer 51, and the microcomputer 51 outputs a detection signal that the door 12 has been opened from the door open / close detection circuit. Upon receiving the signal, the relay 7 of the motor drive circuit was turned off to stop the drum drive motor 3. In the case of this conventional example, when the relay switch 71 of the motor drive circuit is held in the ON state and a short-circuit failure (ON failure) that cannot be turned off occurs, the microcomputer 51 outputs a command signal to turn off the relay 7. However, the drum drive motor 3 could not be driven and stopped, and the rotating drum 2 continued to rotate even when the door 12 was open.

On the other hand, in the present embodiment, the door switch 16 is electrically connected in the motor drive circuit 6, and when the door 12 is opened and the door switch 16 is turned off, the energization of the drum drive motor 3 is cut off. .. Therefore, not only when the relay 7 operates normally, but also when the relay switch 71 is short-circuited, the door switch 16 cuts off the energization of the drum drive motor 3 in the motor drive circuit 6, and a command from the microcomputer 51 ( Regardless of the relay drive signal), the drum drive motor 3 can be driven and stopped to stop the rotation of the rotating drum 2, and the rotating drum 2 does not continue to rotate with the door 12 open. Therefore, when the relay switch 71 is short-circuited, the door 12 can be opened without pulling out the power plug of the clothes dryer 1 from the outlet to stop the drum drive motor 3 as in the conventional case. The drum drive motor 3 can be driven and stopped. Next, when the door 12 is closed, the door switch 16 is turned on and the power cutoff of the drum drive motor 3 is released, so that the rotating drum 2 can be rotated again.

Further, conventionally, a door open / close detection circuit including a door switch 16 and a motor drive circuit are separately provided in order to stop the rotation of the rotary drum 2 when the door 12 is opened. However, according to the above configuration, the motor The drive circuit 6 can have a circuit configuration having a function of a door open / close detection circuit, and it is not necessary to separately provide a door open / close detection circuit. Therefore, the configuration of the entire circuit in the controller 5 can be simplified.

Further, in the motor drive circuit 6, the microcomputer 51 is signal-connected to the series circuit 61 of the drum drive motor 3 and the relay switch 71 via the signal transmission circuit 62. That is, in the motor drive circuit 6, both terminals on the light emitting element (light emitting diode or the like) side of the photocoupler 9 which is a current operating element are connected to the contacts 61a and 61b at both ends of the series circuit 61, and the light receiving element of the photocoupler 9 is connected. The output terminal on the (light receiving transistor, etc.) side is connected to the input terminal 51b of the microcomputer 51. Further, a resistor 91 for current limiting is connected to the wiring on the light emitting element side of the photocoupler 9, and the amount of electricity supplied to the light emitting element is limited so as not to increase. The signal transmission circuit 62 is configured by a circuit that connects the photocoupler 9 and the resistor 91 in series.

In the light emitting element of the photocoupler 9, when a current flows through the drum drive motor 3 of the series circuit 61, a current flows through the light emitting element to emit light, and when no current flows through the drum drive motor 3, no current flows through the light emitting element. It will not emit light. When the light receiving element of the photocoupler 9 receives light from the light emitting element, a current flows through the output terminal (between the collector and the emitter), and when it does not receive light from the light emitting element, the output terminal (between the collector and the emitter). Is configured so that no current flows through it. Therefore, in the microcomputer 51, the drum drive motor 3 is driven in the energized state by the output of the photocoupler 9 (current from the collector side terminal of the light receiving element), and the drum drive motor 3 is de-energized. It is possible to recognize that the drive is stopped in the state.

That is, according to the motor drive circuit 6, as described above, when the door 12 is opened, the drum drive motor 3 is driven and stopped regardless of the command (relay drive signal) from the microcomputer 51. At this point, the microcomputer 51 is unaware that the door 12 has been opened. However, the microcomputer 51 can recognize that the drum drive motor 3 has been driven and stopped through the output from the motor drive circuit 6, that is, the signal transmission circuit 62 of the motor drive circuit 6. Therefore, even if the microcomputer 51 does not have the door open / close detection circuit including the door switch 16 as in the conventional case, the microcomputer 51 is driven by the drum because the door 12 is opened during the drying operation by the output from the motor drive circuit 6. It can be recognized that the motor 3 has stopped driving.

When the door 12 is opened and the drive stop of the drum drive motor 3 is recognized, the microcomputer 51 outputs a command signal (valve closing signal) to close the valve device 43 of the burner unit 4. As a result, for example, the first solenoid valve 43a and the second solenoid valve 43b of the valve device 43 are closed, and the gas burner 41 is extinguished. Therefore, the combustion exhaust gas from the burner unit 4 does not flow into the rotating drum 2 in the stopped rotation state or leak from the clothing take-out port 11 in the open state of the door 12. Therefore, a part of the clothes C in the rotating drum 2 that has stopped rotating may be overheated and hurt, or the user standing in front of the clothes outlet 11 with the door 12 open may be exposed to the hot air of the combustion exhaust gas. The situation can be avoided. Further, the combustion exhaust gas does not stay around the burner unit 4 and a part of the clothes dryer 1 is not overheated. In the motor drive circuit 6 of FIG. 2, when the relay switch 71 is in the off state, the microcomputer 51 can recognize the on / off state of the door switch 16 (open / closed state of the door 12) by the output of the photocoupler 9. ..

The present invention is not limited to the present embodiment, and various modifications can be made within the scope of the gist of the present invention.
For example, when the door 12 is opened during the drying operation and the drum drive motor 3 is stopped by the motor drive circuit 6, the microcomputer 51 outputs an off signal (command signal) for turning off the relay switch 71 of the relay 7. The relay switch 71 may not be operated. As a result, the number of on / off durability of the relay switch 71 can be reduced, so that the life of the relay 7 can be extended. In this case, the relay switch 71 is held in the ON state, but the drive stop of the drum drive motor 3 is held by turning off the door switch 16.

Further, the motor drive circuit 6 further installs sensors (15a to 15d, 13b, etc.) provided for overheating prevention such as an overheat switch and a thermal fuse in the circuit of the path through which the current of the AC power supply 8 flows to the drum drive motor 3. It may be connected in series. As a result, even if the relay switch 71 has a short-circuit failure when the overheat switch or the thermal fuse is turned off due to abnormal overheating, the motor drive circuit 6 immediately stops the drum drive motor 3 to drive the rotating drum. 2 can be stopped rotating, and further, the microcomputer 51 that recognizes the drive stop of the drum drive motor 3 by the output from the motor drive circuit 6 controls to close the valve device 43 to extinguish the gas burner 41. can do.

1 Clothes dryer 2 Rotating drum 3 Drum drive motor 4 Burner unit 5 Controller 6 Motor drive circuit 7 Relay (switching element)
8 AC power supply 9 Photocoupler (current operating element)
10 Body case 11 Clothes outlet 12 Door 16 Door switch 16a Pin 41 Gas burner 42 Gas supply pipe 43 Valve device 51 Microcomputer (control unit)
61 Series circuit 62 Signal transmission circuit 71 Relay switch 91 Resistance C Clothing

Claims (1)

A rotating drum that houses the object to be dried,
A door that opens and closes the outlet for the object to be dried on the rotating drum,
A drum drive motor that rotates and drives a rotating drum,
A motor drive circuit that turns on and off the switching element to energize and de-energize the drum drive motor ,
A gas burner that generates combustion exhaust gas to be sent into the rotating drum, and a burner unit that has a valve device for supplying fuel gas to the gas burner.
Equipped with a control unit that connects to the motor drive circuit
The motor drive circuit electrically connects a door switch that turns on and off in conjunction with the opening and closing of the door in the circuit, shuts off the energization of the drum drive motor when the door opens and the door switch turns off, and energizes the drum drive motor. The circuit configuration is such that the cutoff state is transmitted to the control unit.
The control unit recognizes the drive stop of the drum drive motor when the switching element or the door switch is turned off and the energization of the drum drive motor in the motor drive circuit is cut off, and is linked to the drive stop of the drum drive motor. A clothes dryer that controls the valve device of the burner unit to close.

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