JPS62123257A - Temperature control unit for hot air flow apparatus - Google Patents

Abstract

PURPOSE:To make it possible to conduct a stable air flow temperature control and make the set temperature variable in a wide range by providing a microheater for heating a PTC thermistor and means for variably setting the quantity of power supply, in the temperature control unit such as a hair drier or the like. CONSTITUTION:A heater 7 is connected in series to a phase control element 14, and connected to a commercial power source 17. A series circuit of a PTC thermistor 10a and a capacitor 16 is connected in parallel to the phase control element 14, and a junction between the PTC thermistor 10a and a capacitor 16 is connected to the gate of the phase control element 14. A series circuit consisting the microheater 10b of the PTC thermistor 10a and the capacitor 16 and a variable resistor 9 is connected in parallel to a series circuit of the heater 7 and the phase control element 4. By adjusting the variable resistor 9, the PTC thermistor 10a is heated by the PTC thermistor 10b to make a temperature difference between an air flow temperature due to the heater 7 and a temperature detected by the PTC thermistor 10a, the setting of the air flow temperature is carried out, and the change of the air flow temperature is detected as usual in the PTC thermistor 10a. Hence, the control of the air flow temperature does not get unstable.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a temperature control device applied to a device for obtaining hot air such as a hair dryer.

(Background technology) In devices that obtain hot air such as hair dryers, even if there are changes in the ambient temperature due to summer or winter, the air volume may change due to a decrease in the rotation speed of the fan or if the suction port or discharge port is blocked. A phase control type wind temperature control device is used that can keep the wind temperature constant even when there is a change in the air temperature, and can set the wind temperature variably.

For example, in Japanese Patent Application Laid-Open No. 59-156309, the heater 70 is connected to a phase control element 7 such as a triac as shown in FIG.
1, the conduction angle of the phase control element 71 is controlled by the PTC thermistor 72 to keep the air temperature constant, and a variable resistor 73 is connected in series to the PTC thermistor 72 to variably set the air temperature. Equipment is shown. In addition,
? 4 is phase i! llI! A bidirectional switching element supplies a gate current to the gate of the element 71, 75 is a capacitor charged through a PTC thermistor 72 and a variable resistor 73, 76 is a motor for rotating the fan, and 77 is a commercial power source.

However, this air temperature control device operates as follows when the resistance value of the variable resistor 73 is increased (increased) for the purpose of lowering the set temperature, for example. That is, the conduction angle of the phase control element 71 decreases → the temperature of the heater 70 decreases → the air temperature decreases → the temperature of the PTC thermistor 72 decreases → the resistance value of the PTC thermistor 72 decreases.The conduction angle of the phase control element 71 decreases. It becomes larger - the temperature of the heater 70 rises → the air temperature rises... the result,
Even if an attempt is made to change the set temperature by changing the resistance value of the variable resistor 73, the air temperature does not change much due to the action of the PTC thermistor 72. Conversely, the same applies when increasing the set temperature. Note that if the resistance value of the variable resistor 73 is greatly changed, the conduction angle of the phase control element 71 can be changed to arbitrarily change the air temperature. There is a limit to the variable range of the variable resistor 73 because the rate at which changes are fed back to the phase cavity changes, resulting in unstable air temperature control.

Therefore, this type of conventional air temperature control device has a drawback that the variable range of the set temperature is small. In the case of a hair dryer, the setting range is limited when it is desired to change the air temperature according to the setting condition or preference when drying and setting the hair, resulting in an inconvenience that it is not easy to use.

(Objective of the Invention) The present invention I has been proposed in view of the above points, and its purpose is to provide a wind temperature that can stably control the air temperature at a set temperature and that can vary the set temperature over a wide range. The purpose is to provide a control device.

(Disclosure of invention) DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to drawings showing embodiments.

A first example in which the present invention is applied to a hair dryer is shown in the first example.
This will be explained based on the drawings to FIG.

Figure 1 shows the mechanical configuration of the hair dryer, in which a suction port 2 is formed at the rear of the main body 1, a discharge port 3 is formed at the tip, and a fan 4 is provided inside from the suction port 2 side. Motor 5. Circuit board of air temperature control device6. Heaters 7 are arranged one after another. Further, 8 is a switch for switching between "off,""coldair," and "warm air," 9 is a variable resistor for adjusting the air temperature, and 0 is installed on the heater board 11 that supports the heater 7. PTC thermistor 10a and micro heater 1
0b is integrated with the temperature sensor element, and 13 is a power cord.

In addition, the temperature sensor element 10 is shown in detail in FIG.
The micro heater 10b is placed on the front side in the air blowing direction, and the PT
The area of the C thermistor 10a facing the air blowing direction is smaller than the area of the micro armature 10b. Moreover, FIG. 3 shows a specific example of the configuration of the temperature sensor element IO, in which (a) is a perspective view, (b) is a sectional view taken along line A-A in (a), and (c) is (i). ). Thus, the PTC thermistor 10a is soldered and fixed to the electrode 10d formed on one surface of the substrate 10c on which the micro-heater 10b is formed, and the lead wire 10e is taken out from the electrode 81i10d6. FIG. 4 shows an example of the circuit configuration of the control device. Fourth
In the figure, a heater 7 is connected in series with a phase control element 14 such as a triac, and is connected to a commercial power line #17 via a switch 8 and a noise prevention coil 23.
Temperature sensor element] PTC of O in parallel with phase control element 14
A series circuit of a thermistor 10a and a capacitor 16 is connected, and a connection point between the PTC thermistor 10a and the capacitor 16 is connected to the gate of the phase control element 14 via a bidirectional switching element 15 such as an SBS. Further, the series circuit of the micro heater 10b of the temperature sensor element 10 and the variable resistor 9 is connected in parallel with the series circuit of the heater 7 and the phase control element 14, and the amount of current to the micro heater 10b is controlled by adjusting the variable resistor 9. Variable PTC thermistor 10m
It is now possible to add a temperature difference to the wind temperature.

Note that 18 and 19 are diodes, 20 is a resistor, and 27 is a capacitor for noise prevention. Further, the fan rotation motor 5 is connected between the DC terminals of the diode bridge 21 via noise prevention coils 24 and 25, and the AC terminal of the diode bridge 21 is connected to the heater 7 and the heater 7 via a resistor 22.
It is connected in parallel with the series circuit of the phase control element 14.

Note that 26 is a capacitor for noise prevention.

Therefore, the wind temperature stabilization operation of this wind temperature control device is effective against changes in wind temperature caused by external factors such as ambient temperature or a decrease in air volume.
For example, the air temperature increases → the temperature of the PTC thermistor 10a increases → the resistance value of the PTC thermistor 10a increases →
The conduction angle of the phase control element 14 becomes smaller → the power of the heater 7 decreases → the air temperature decreases, and conversely, the air temperature decreases → the temperature of the PTC thermistor 10a decreases →
The resistance value of the PTC thermistor 10a decreases, the conduction angle of the one-phase control element 14 increases → the power of the heater 7 increases →
The air temperature rises and is maintained at a predetermined temperature.

Next, when setting the air temperature, the variable resistor 9 is operated. For example, when setting the air temperature to a low value, the resistance value of the variable resistor 9 is reduced → the power of the micro heater 10b is goes up→The temperature of PTC thermistor 10a goes up→
The resistance value of the PTC thermistor 10m increases → the conduction angle of the phase control element 14 decreases → the power of the heater 7 decreases →
The wind temperature drops... it roars. On the other hand, if you want to set the air temperature high, you can increase the resistance value of the variable resistor 9.The operation is as follows: Increase the resistance value of the variable resistor 9→The power of the micrometer 10b decreases→PTC The temperature of the thermistor 10a decreases → the resistance value of the PTC thermistor 10a decreases, the conduction angle of the one-phase control element 14 increases → the power of the heater 7 increases → the air temperature increases...
bawl.

In this way, the air temperature can be set by heating the PTC thermistor 10a with the micro and overnight 10b and creating a temperature difference between the air temperature by the heater 7 and the temperature detected by the PTC thermistor 10a. The set temperature can be varied over a wide range. In addition, PTC thermistor 10
Since changes in the air temperature are detected as usual in a, the air temperature control will not become unstable.

Further, in this first embodiment, the PTC thermistor 10m and the micro heater 10b are integrated, and the micro heater 1
0b is placed on the front side in the air blowing direction, and P facing the air blowing direction is placed.
Since the area of the TC thermistor 10a is smaller than that of the micro-heater 10b, the PTC thermistor 10a efficiently receives and takes the amount of heat from the micro-heater 10b, and since it is not directly exposed to the wind from the fan, it receives less heat from the micro-heater 10b. Since less of the generated heat is allowed to escape, the power supplied to the micro-heater 10b can be reduced, and there is an advantage that a variable resistor 9 with a small allowable power can be used.

Next, FIG. 5 shows a second embodiment, in which the PTC thermistor 10m of the temperature sensor element 10 and the micro-heater 10b have approximately the same area facing the air blowing direction as the first embodiment. The same is true.

Therefore, in this second embodiment, the PTC thermistor 10
a and the micro heater 10b are integrated, the micro heater 10b is placed on the front side in the air blowing direction, and the area of the PTC thermistor 10a facing the air blowing direction is the area of the micro heater 10.
b, so that the PTC thermistor 10a efficiently receives and takes away the amount of heat from the micro heater 10b.
Moreover, since the wind from the fan is directly received only from the side, the micro heater 10 is slightly inferior to the first embodiment.
There is an advantage that less heat is lost from the heat source b, and the response time to wind temperature can be shortened.

Therefore, in this second embodiment, the micro heater 10
There are advantages in that the electric power applied to b can be minimized, the response time can be shortened, and the temperature can be set over a wide range.

Next, FIG. 6 shows a third embodiment, which is the same as the second embodiment except that the positions of the PTC thermistor 10 & of the temperature sensor element 10 and the micro heater 10b with respect to the air blowing direction are reversed. . That is, PTC thermistor 10
m and micro heater lOb are integrated, PTC thermistor 10m is placed on the front side in the air blowing direction, and the area of PTC thermistor 10& facing the air blowing direction is
It is made almost the same as 0b.

However, since the PTC thermistor 10m directly receives the wind from the fan, its response characteristics to wind temperature are greatly improved.
Furthermore, since it is integrated with the microheater 10b, there is an advantage that a wide range of temperature settings can be made with the smallest microheater power when response time is important.

(Effects of the Invention) As described above, the present invention includes a motor that drives a fan, a heater that heats the air blown out by the fan, a phase control element that controls the phase of this heater, and a phase control element that controls the air temperature. A temperature control device for a hot air heater, comprising: a PTC thermistor that detects and controls the phase control element to keep the air temperature constant; and a temperature variable setting means that variably sets the detected temperature of the PTC thermistor. The temperature variable setting means is composed of a microheater that heats the PTC thermistor and a means for variably setting the amount of current applied to the microheater, and the PTC thermistor and the microheater are integrally joined. b) The wind temperature is set by applying a temperature difference to the actual wind temperature using a PTC thermistor, and the set temperature can be varied over a wide range while maintaining the stability of wind temperature control.

(b) Since the PTC thermistor can efficiently receive the amount of heat from the microheater and is difficult to release the applied heat, the power applied to the microheater can be reduced. Therefore, a variable resistor with a small allowable power can be used as a variable resistor for controlling the power of the microheater.

There are other effects.

[Brief explanation of drawings]

1 to 4 show a first embodiment in which the present invention is applied to a hair dryer, FIG. 1 is a mechanical configuration diagram, and FIG.
Figures 3 and 3 are detailed diagrams of the temperature sensor element, and Figure 4 is the wind temperature IIIW! 1 is a circuit configuration diagram of the device, FIG. 5 is a configuration diagram of a temperature sensor element showing a second embodiment, FIG. 6 is a configuration diagram of a temperature sensor element showing a third embodiment, and FIG. 7 is a diagram of a conventional temperature sensor element. It is a circuit block diagram of a temperature control device. 1...Main body, 2...Suction port, 3...
...Discharge port, 4...Fan, 5...
Motor, 6...Circuit board, 7...Heater, 8...Switch, 9...Variable resistor,! O...Temperature sensor element, 10m...
...PTC thermistor, 10b...Micro heater, 11...Heater board, 13...
Power cord, 14... Phase control element, 15...
・・・Bidirectional switch element, 16・・・Capacitor, 17・・・Commercial power supply and 1 other person

Claims (4)

[Claims] (1) A motor that drives a fan, a heater that heats the air blown by the fan, a phase control element that controls the phase of this heater, and a phase control element that controls the phase control element by detecting the air temperature. A temperature control device for a hot air fan, comprising a PTC thermistor that keeps the temperature constant, and a temperature variable setting means that variably sets the detected temperature of the PTC thermistor, the device comprising: a micro heater that heats the PTC thermistor; 1. A temperature control device for a warm air fan, characterized in that said temperature variable setting means is constituted by means for variably setting the amount of current applied to a heater, and said PTC thermistor and micro heater are integrally joined. (2) Temperature control of the air warmer according to claim 1, in which the microheater is arranged on the front side in the air blowing direction than the PTC thermistor, and the area of the microheater facing the air blowing direction is larger than that of the PTC thermistor. Device. (3) The air warmer according to claim 1, wherein the micro-heater is arranged in front of the PTC thermistor in the air blowing direction, and the area of the micro-heater facing the air blowing direction and the area of the PTC thermistor are substantially the same. Temperature control device. (4) A temperature control device for an air warmer according to claim 1, which comprises a micro-heater and a PTC thermistor joined together by soldering.