JPS5924320Y2 - Dryer - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a dryer using a positive temperature coefficient thermistor as a heat source.

Conventionally, dryers using positive temperature coefficient thermistors have been used as a safe heat source that does not become red hot. In some cases, the heat generating capacity, that is, the flowing current is large, and when the outside air temperature is high and the intake air temperature is high, such as in the summer, the heat generating capacity, that is, the flowing current is small. There is a problem that the heat generation capacity is not constant and the degree of drying of the material to be dried varies, and when the outside temperature is extremely low such as in winter, an extremely large current flows through the positive characteristic thermistor, which is detected as an abnormal current. There was a problem that the current fuse would blow or the current breaker would trip and cut off the power, making drying operation impossible.

The present invention was developed in view of the above circumstances, and its purpose is to stabilize the current flowing through the positive temperature coefficient thermistor, that is, the heat generation capacity, even when the intake air temperature changes significantly due to changes in outside air temperature in winter and summer. A dryer that does not have the risk of variations in the degree of drying of the material to be dried, does not have the problem of the current fuse or current breaker turning off the power when the outside temperature is low, and can shorten the drying time even when the outside temperature is high. It is on offer.

An embodiment of the present invention will be described below based on the drawings. First, in FIG. 1 showing the overall structure, 1 is a rotating drum with a drying chamber 2 inside, which is placed inside an outer box 3. It is rotatably supported, and its rotation agitates the material to be dried, such as clothes, inside.

A recess 4 that bulges into the drying chamber 2 is formed at the rear end of the rotating drum 1, and a casing 6 is provided to close the recess 4. It is defined.

Reference numeral 7 denotes an intake cylinder, one end of which communicates with the inside of the fan chamber 6 through an intake port 8 formed in the casing 5, and the other end of which passes through the back plate of the outer box 3 and faces the outside.

9 is, for example, 3 arranged in the intake cylinder 7 so as to close it.
A positive temperature coefficient thermistor, which is formed into a ventilated honeycomb shape.

10 is a shutter device that changes the effective area of ventilation in the intake cylinder 7, which is the effective area of the ventilation passage through the positive temperature coefficient thermistor 9, and this is constructed as shown in FIGS. 2 and 3. .

That is, reference numeral 11 denotes a DC motor including a speed reduction mechanism so that its rotating shaft 11a rotates at a low speed.

Reference numeral 1212 denotes an arm supported by the case of the DC servo motor 11, and a connecting shaft 13 is rotatably supported between each arm 12 with a frame passing therebetween.

Reference numeral 14 denotes a shutter plate whose lower end is connected and fixed to the connecting shaft 13, and as it rotates, it moves into the intake pipe 7, particularly at a portion close to the intake surface side of the positive characteristic thermistor 9 (left side in FIG. 2). It is arranged so that it appears.

Therefore, when the shirt flap plate 14 is rotated in the direction of arrow A in FIG.
When rotated in the opposite direction of arrow A, the amount of ventilation increases.

The rotational force of the DC servo motor 11 is transmitted to the shirt plate 14 via a worm 15 fixed to the rotating shaft 11a and a worm wheel 16 fixed to the connecting shaft 13. , rotating shaft 11
When a rotates in the direction of arrow B in FIG. 2, the shirt flap plate 14 rotates in the direction of arrow A, and when it rotates in the opposite direction of arrow B, the shirt flap plate 14 rotates in the opposite direction of arrow A. be done.

Now, turning back to FIG. 1, reference numeral 17 is a motor disposed at the lower part of the outer box 3, which rotates the rotary drum 1 via a belt 18, and also rotates the rotary drum 1 via another belt 19 to the fan chamber 6.
While rotating the circulation fan 20 disposed inside,
The suction/exhaust fan 22 inside the fan casing 21 is rotated.

The fan casing 21 is communicated from its front end into the drying chamber 2 through a filter chamber 23 and a gap 25 around the door 24, and communicated with the outside through an exhaust duct 26 at its rear end.

Further, 27 is a large number of ventilation holes formed in the center of the recess 4, 28 is a large number of ventilation holes formed in the periphery of the recess 4,
29 is a timer device arranged at the upper part of the front side of the outer box 3.

Next, the electrical configuration will be explained according to FIG.

That is, 30 is a 100 AC power source, and a cam switch 29a of a timer device 29 and a positive temperature coefficient thermistor 9 are connected between both terminals of the power source. A series circuit including a primary winding 31a of a current transformer 31 serving as a current detection section, a fuse 32, and a door switch 24a that is closed only when the door 24 is closed is connected.

Further, the cam switch 29 of the timer device 29 is connected in parallel to the series circuit of the cam switch 29 a and the positive temperature coefficient thermistor 9.
b and the motor 17 are connected in series, and the motor 17
A timer motor 29C of the timer device 29 is connected in parallel with the timer motor 29C of the timer device 29.

The timer device 29, when set, closes the cam switches 29a and 29b, and opens the cam switch 29a a predetermined time before the end of the timed operation for the set time, thereby ending the timed operation. When the cam switch 2
This is a well-known configuration in which 9b is opened.

On the other hand, 33 is a drive device, which will be described below.

34 is a voltage converter, which is the current transformer 31
The detection voltage ■ is proportional to the current value flowing through the secondary winding 31b.

Output. Therefore, the detection voltage ■.

is proportional to the current ID detected by the current transformer 31 (corresponding to the full load current flowing through the positive temperature coefficient thermistor 9, motor 17, etc.).

Reference numeral 35 denotes an operational amplifier functioning as a differential amplifier, into which the detection voltage VD is inputted to its inverting input terminal (-), and the reference voltage (2) from the reference voltage generation circuit 36 is inputted to its non-inverting input terminal (G).

At this time, if the configuration is such that, for example, a total of 2 A of current flows through the motor 17 and the timer motor 29C, the detected current (2).

is 15A, that is, when the positive temperature coefficient thermistor 9 is connected to 1
Detected voltage ■ when 3A current flows.

and the reference voltage Vs are set in advance to be equal. Therefore, since the voltage of the power supply 30 is 100μ, when the output of the positive temperature coefficient thermistor 9 is 1300W, the operational amplifier 3
The output of 5 becomes zero potential.

Also, when the output of the positive characteristic thermistor 9 becomes smaller than 1300 W, the detection voltage becomes ■.

and the reference voltage v5 have a relationship of Vo<Vs, and the output of the operational amplifier 35 becomes a positive voltage. Conversely, when the output of the positive characteristic thermistor 9 becomes greater than 1300 W, the relationship of Vs<Vn occurs. As a result, the output of the operational amplifier 35 becomes a negative potential.

37 and 38 are positive and negative power supply terminals, and the collectors and emitters of transistors 39 and 40 are connected in series between them, and the bases of transistors 39 and 40 are connected directly to the output terminal of the operational amplifier 35. are connected via an inverter 41.

The DC servo motor 11 is connected between the common connection point of the emitter of the transistor 39 and the erector of the transistor 40 and the ground terminal.

The DC servo motor 11 rotates its rotating shaft 11a in the opposite direction of arrow B in FIG. 2 when it receives current from the positive power terminal 37, and when it receives current from the negative power terminal 38. The rotating shaft 11a is rotated in the opposite direction, in the direction of arrow B.

Next, the operation of the configuration described in "2" will be explained with reference also to FIGS. 5 and 6.

That is, in FIG. 5, the horizontal axis shows the outside air temperature T'C, and the vertical axis shows the output p (w) of the positive temperature coefficient thermistor 9.
It can be understood from FIG. 5 that when the amount of ventilation through the positive temperature coefficient thermistor 9 is constant, the output of the stopper characteristic thermistor 9 with a low outside temperature type T increases.

In addition, in FIG. 6, the horizontal axis shows the ventilation amount Q (m3/min) through the positive temperature coefficient thermistor 9, and the vertical axis shows the output P (W) of the positive temperature coefficient thermistor 9. 20
It shows the change characteristics of the output P in each case of 30°C and 30°C.

However, after putting wet clothes into the drying room 2, the door 2
4 to close the door switch 24a, and in this state set the timer device 29 to close the cam switch 2.
When 9a and 29b are closed, timer motor 2
9 C is energized and the timer device 29 opens and closes the timed operation, and the positive temperature coefficient thermistor 9 is energized and generates heat.
At the same time, the motor 17 is energized and rotates.

Then, rotating drum 1. The circulation fan 20 and the suction/exhaust fan 22 are rotated at predetermined speeds, and the outside air is sucked into the intake cylinder 7 by the rotation of the suction/exhaust fan 22, and is hot-aired in the process of ventilating the positive temperature coefficient thermistor 9. is supplied to the drying chamber 2 via the chamber 6 and the group of ventilation holes 28,
After this, the air gap 25. Filter chamber 23. It is exhausted to the outside via the fan casing 21 and the exhaust duct 26.

On the other hand, the rotation of the circulation fan 20 causes the air in the drying chamber 2 to circulate through the ventilation holes 27, 28, thus starting the hot air drying operation.

By the way, at the start of such a hot air drying operation, the shirt flap plate 14 is at the position shown by the solid line in FIG. and the outside temperature T is, for example, 5℃.
When this happens, the output P of the positive temperature coefficient thermistor 9 reaches approximately 1400 W, as understood from FIG.

Therefore, the relationship between the detected voltage VD from the voltage converter 34 and the reference voltage V5 becomes Vs<VD, and the operational amplifier 3
The output of the transistor 5 becomes a negative potential, and the transistor 40 is turned on.

Therefore, the DC servo motor 11 receives current from the negative power supply terminal 38 and its rotating shaft 11a is rotated in the direction of arrow B, and this rotation causes the shutter plate 14 to move in the direction of arrow A, that is, the amount of airflow through the positive temperature coefficient thermistor 9. It is rotated in the direction of decreasing Q.

Then, when the shirt flap plate 14 is rotated to the position shown by the two-dot chain line in FIG.
The output P of the sensor decreases to 1300 W, and therefore the detection voltage V
l) and the reference voltage (5) become equal, and the output of the operational amplifier 35 becomes zero potential, so the transistor 40 is turned off, thereby stopping the drive of the DC servo motor 11 and causing the shutter plate 14 to move as shown by the two-dot chain line above. held in position.

On the other hand, when the air flow rate Q of the positive temperature coefficient thermistor 9 is adjusted to, for example, 0.6 m3/min by the shirt shutter plate 14 at the start of the hot air drying operation, and the outside air temperature T is, for example, 30°C, as shown in FIG. The output P of the positive characteristic thermistor 9 is
However, if the drying operation continues as it is, the required time may become longer.

However, in this case, the detection voltage ■.

Since the relationship between and the reference voltage ■5 becomes ■9〈V5, the output of the operational amplifier 35 becomes a positive potential, so that the transistor 3
9 is turned on, the DC servo motor 11 receives current from the positive power supply terminal 37, and its rotating shaft 11a is rotated in the opposite direction of arrow B. This causes the shutter plate 14 to move in the opposite direction of arrow A, that is, the positive characteristic thermistor 9. It is rotated in a direction to increase the amount of ventilation Q through.

When the ventilation amount Q is increased to, for example, 0.9 m3/min by the rotation of the shirt shutter plate 14, the output P of the positive temperature coefficient thermistor 9 increases to 1300 W as shown in FIG. The voltage VD and the reference voltage 5 become equal, and in this state, the driving of the DC servo motor 11 is stopped and the shirt flap plate 14 is held at the position where the ventilation amount Q is adjusted to 0.9 m3/min.

Therefore, even when the outside air temperature T is high, the drying time can be shortened.

As described above, the output P of the positive temperature coefficient thermistor 9 is 13
The hot air drying operation continues with the temperature adjusted to 00 W, and then, when a predetermined time before the timer device 29 ends the timed operation, the cam switch 29a opens and the energization to the positive temperature coefficient thermistor 9 is stopped. After that, cold air operation will be performed.

When the cam switch 29b is opened after such cold air operation is performed for a predetermined period of time, the timer motor 29C and the motor 17 are cut off, and the drying operation is completed.

According to the present invention, as is clear from the above explanation, the amount of airflow through the PTC thermistor is adjusted according to the magnitude of the current flowing through the PTC thermistor, and thereby, regardless of the outside temperature. Since the output of the positive characteristic thermistor can be automatically kept constant at all times, the heat generating capacity can be stabilized even when the intake air temperature, that is, the outside air temperature, changes significantly, and there is no risk that the degree of drying of the dried material will vary. Even when the outside temperature is high, such as in the summer, it is possible to obtain a larger heat generation capacity than in the past, and the drying time can be shortened.

Furthermore, even when the outside temperature becomes extremely low at the end of winter, there is no risk that an extremely large abnormal current will flow through the PTC thermistor, thereby preventing the problem of a current fuse or current breaker turning off the power.

[Brief explanation of the drawing]

The drawings relate to one embodiment of the present invention; Fig. 1 is a partially cutaway side view of the whole, Fig. 2 is an enlarged longitudinal sectional side view of the main part, and Fig. 3 is a position of the positive temperature coefficient thermistor and the shirt plate. 4 is an electric circuit diagram, FIG. 5 is a diagram showing the output characteristics of the PTC thermistor with respect to changes in outside temperature, and FIG. 6 is a diagram showing the output characteristics of the PTC thermistor with respect to changes in ventilation amount. In the figure, 2 is a drying chamber, 7 is an intake cylinder, 9 is a positive temperature coefficient thermistor, 10 is a shutter device, 14 is a shutter plate, 31 is a current transformer (current detection section), and 33 is a drive device.

Claims (1)

[Scope of utility model registration request] The drying chamber includes a positive temperature coefficient thermistor for hot airing outside air supplied into the drying chamber, comprising: a shutter device that adjusts the amount of ventilation by changing the effective area of the ventilation passage through the positive coefficient thermistor; A drying device comprising: a current detection section that detects a current flowing through a characteristic thermistor; and a drive device that drives the shutter device to adjust the airflow amount according to the magnitude of the current detected by the current detection section. Machine.