JPH0248280B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is capable of turning off the power to the heater when the fan belt of the blower fan that sends hot air to the rotating drum containing clothes breaks, or when the drum belt of the rotating drum breaks. This invention relates to a clothes dryer designed to ensure safety.

A conventional clothes dryer is constructed as shown in FIG. In Fig. 1, 1 is an outer box, 2 is a rotating drum, 3 is a drum front plate fixed to the front plate 1a of the outer box 1, and 4 is a lid for a clothes input port, and an air intake port 4a is located at the lower front of the lid. A filter 5 is provided to prevent foreign matter from being inhaled from the intake port 4a. 1b is a louver formed on the outer box front plate 1a. A heater case 6 fixedly supports a semiconductor heater (hereinafter abbreviated as PTC heater) 7, and is held between the outer box front plate 1a and the drum front plate 3. 3a is a hot air discharge port formed in the front plate 3 of the drum. 8 is a fan case, which has a built-in blower fan 9. 10 is a fan pulley attached to the shaft of the blower fan 9, and 11 is a motor pulley, which is attached to the main shaft 12 of the motor 14.
A fan belt 13 connects the motor pulley 11 and the fan pulley 10. A drum pulley 15 is attached to the main shaft 12 of the motor 14 and transmits power to the rotating drum 2 via a drum belt 16. 17 is an idler pulley that applies tension to the drum belt 16; 18 is a spring that biases the idler pulley; and 19 is a filter case that houses a filter 20 that collects dust from clothing in the rotating drum 2.

In the above configuration, the rotating drum 2 containing clothes
At the same time, inside this rotating drum 2,
Sending hot air heated through the PTC heater 7,
Stir and dry the clothes. However, the conventional example configured in this manner has the following drawbacks.
First, if the fan belt 13 should break, the blower fan 9 will stop, and therefore the ventilation of the PTC heater 7 will stop. When the passing air volume disappears, the temperature of the heating element rises rapidly to approximately 220°C. However,
The PTC heater 7 has a positive temperature coefficient of resistance, and due to its characteristics, it self-controls the current input, and when the temperature rises, the input decreases, acting to lower the temperature of the heating element. For this reason, PTC heaters do not get red hot like conventional nichrome heaters and are safe heaters. However, as shown in Fig. 2, the clothes in the rotating drum 2 fall from top to bottom as the drum 2 rotates, and wind is generated accordingly.
Among them, the air flowing toward the hot air outlet 3a in the direction of arrow A hits the PTC heater. PTC heater 7
Since the temperature has risen to about 220°C, the vicinity of the air inlet 4a of the lid 4 receives hot air of about 120°C.

In this case, the resin lid 4 was easily deformed when subjected to heat of 120° C., especially when the ambient temperature was high as in the summer. Furthermore, the intake filter 5 was also deformed. Furthermore, there was a risk of burns if the area near the air intake port 4a of the lid 4 was touched carelessly with a hand or the like. Next, when the drum belt 16 breaks, the rotating drum 2 stops, and the agitation of the clothes stops. For this reason, the hot air from the PTC heater 7
Only the clothes near the hot air outlet 3a were heated, and there was a risk of burning the clothes.

The present invention was made in order to eliminate the drawbacks of the above-mentioned conventional example, and includes a safety switch that turns off the power to the PTC heater as soon as the fan belt or drum belt breaks, thereby preventing the lid and filter from deforming. At the same time, the present invention provides a clothes dryer that eliminates risks such as burns. Hereinafter, embodiments will be described in detail with reference to the drawings.

FIG. 3 shows an embodiment of the present invention.
It is a diagram seen from the back side of the clothes dryer. In addition, the first
Items with the same reference numerals as those in the figures indicate the same items.
21 is an idler pulley that presses against the fan belt 13 and applies tension; 22 is this idler pulley 21
The rotation support shaft 23 rotatably supports the rotation support shaft 21 and urges the rotation support shaft 21 in one direction.
24 is a safety switch, and 25 is a contact spring thereof, the tip of which is in contact with the rotation support shaft 22.

Fan belt 13 is normal, idler pulley 2
In the state shown in FIG. 3 in which contact spring 1 is in pressure contact with fan belt 13, contact spring 2 is in contact with rotation support shaft 22.
By position 5, the safety switch 24 is always closed. However, when the fan belt 13 breaks, the idler pulley 21
The rotation support shaft 22 that supports the rotation support shaft 22 rotates in the direction of arrow B due to the biasing force of the tension spring 23, so that the contact spring 25 opens and the safety switch 24 is opened.
In addition, the idler pulley 17 is connected to the drum belt 16.
Tension is applied by a spring 18 so as to press against the spring 18. If the safety switch 24 is brought into contact with the rotation support shaft of the idler pulley 17, the same effect as in the case of the fan belt 13 can be achieved.

FIG. 5 is an electrical circuit diagram of this embodiment, in which 26 is a timer and 27 is a power supply. The safety switch 24 is
Since it is connected in series to the PTC heater 7 and the safety switch 24 is normally closed, the timer 2
When the PTC heater 6 becomes in operation, the PTC heater 7 is energized. Now, when the fan belt 13 and the drum belt 16 break, the safety switch 24 becomes disconnected, and the power to the PTC heater 7 is cut off, as explained in FIG.

As described above in the embodiments, according to the present invention, when the fan belt breaks or the drum belt breaks, the power to the PTC heater is turned off at the same time, so that clothes do not fall inside the rotating drum. As a result, the temperature of the hot air flowing back does not reach a very high temperature, so thermal deformation of the lid, filter, etc. can be prevented, and there is no danger of burns.

Note that disconnection of the fan belt is detected as an abnormality when the clothes do not dry within the time limit set by the timer, but as shown in Figure 6, the disconnection of the fan belt is caused by a switch 28 with a single-pole double-throw contact, a buzzer 29, etc. Install an alarm, and if the fan belt or drum belt breaks,
If the heater side is opened and the alarm side is closed, the abnormality can be easily detected by the alarm.

[Brief explanation of drawings]

FIG. 1 is a vertical sectional view of a conventional example, FIG. 2 is an explanatory diagram of the ventilation state of the PTC heater section when the fan belt breaks, and FIG. 3 is a configuration diagram of an embodiment of the present invention. Fig. 4 is an explanatory diagram of the operation when the fan belt of the same embodiment breaks, Fig. 5 is an electric circuit diagram of the same embodiment, and Fig. 6 is an electric circuit diagram of another embodiment of the present invention. . 2...Rotating drum, 7...PTC heater, 9...
...Blower fan, 13...Fan belt, 14...
Motor, 21...Idler pulley, 22...Rotation support shaft, 23...Tension spring, 24, 28...Safety switch, 25...Contact spring, 29...Buzzer.

Claims (1)

[Claims] 1. A heat source of a semiconductor heater having positive resistance temperature characteristics, a blower fan that sends hot air passing through the semiconductor heater section to a rotating drum, and a blower fan that sends hot air through a fan belt and the rotating drum via a drum belt. In the clothes dryer, a rotation support shaft of an idler pulley that presses and applies tension to the fan belt and the drum belt, respectively, has a spring that urges the fan belt and the drum belt to apply the tension. A clothes dryer characterized in that a safety switch is provided which opens and closes energization to the heat source by rotating the rotation support shaft.