JPS6313688B2 - - Google Patents

Description

[Detailed description of the invention]

[Technical Field] The present invention relates to a hair dryer. [Background Art] A conventional example of this type of hair dryer is disclosed in Japanese Utility Model Publication No. 56-2883. FIG. 1 shows its basic circuit, in which a series circuit of a heater H and a triax T for phase control is connected to an AC power source, and a motor M is connected to the heater H in parallel. S is trigger element for trigger, VR
is a variable resistor and C ₀ is a capacitor. In this circuit, the rotation of the motor M and the power of the heater H are linked and varied by phase control using a triax T, but the motor rotation speed and the heater power do not match at the same phase angle, and therefore, There was a problem in that the heater power did not change accurately in response to changes in air volume, making it difficult to maintain a constant temperature and making it difficult to use. [Object of the Invention] The present invention has been provided in view of the above-mentioned points, and it is possible to make the air volume variable, and even if the air volume is varied, the temperature of the blown air can be kept constant. To provide a hair dryer whose purpose is to be able to arbitrarily and easily set the air volume. [Disclosure of the Invention] Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings. FIG. 2 is a vertical cross-sectional view of the hair dryer, FIG. 3 is a cross-sectional view taken from FIG. 2, and FIG. 4 is a specific circuit diagram. In FIG. 2, reference numeral 3 denotes a housing constituting an outer shell, into which power is supplied via a cord 1 via a rotary connector 2. _S1 is a main switch, and by operating this switch _S1 , switching is performed between off, cold air, and hot air, as will be described later. Reference numeral 11 denotes an operating section for performing a switching operation of the switch _S1 , which is exposed on the surface of the housing 3 and is slidable. The motor M is disposed approximately in the center of the housing 3, and the motor M is held within a rectifying blade 5 that rectifies the air blown by a fan 4 connected to the rotating shaft of the motor M. These, motor M, fan 4 and rectifier blade 15
The blower is made up of. _H1 is a ribbon-shaped heater, which is wound around the outer periphery of the heater substrate 7, which has a cross-shaped cross section. _S2 short-circuits a part of the voltage dividing resistor R that adjusts the voltage applied to the motor M.
This switch S ₂ is a changeover switch that changes the rotational speed of the air conditioner and changes the air volume. The control circuit 9 mounted on the printed circuit board 10 is a temperature sensor consisting of a positive temperature coefficient thermistor provided on the outlet side of the heater _H1 .
It senses temperature using PTC and controls the air temperature at a constant level. The temperature sensor PTC is attached to the heater board 7, as shown in FIG. 6
is a push button for attaching and detaching an attachment (not shown). 8 is an air outlet. In Figure 4, switch S ₁ has two contacts r ₁ r ₂
One end of the cord ₁ is connected to the terminal of the switch S1, and the terminal is connected to a rectifier DM for applying the voltage to the DC motor M, and a voltage dividing resistor R (R ₁ R ₂ ) that steps down the voltage applied to the motor M. are connected in series. switch
Connect the terminal of S ₁ to one end of resistor R ₂ via a series circuit of coil L for preventing radio wave interference, triax T ₁ for phase control, and heater H ₁ , and
It is connected to the other end of the cord 1 via fuse F. A charging circuit is composed of a temperature sensor PTC that detects hot air and changes the resistance value, and a capacitor _C1 , and when the voltage applied to the trigger element SBS, such as a silicon bidirectional switch, reaches a certain voltage,
The trigger element SBS conducts and sends a gate signal to the triac T, which partially cuts off the current and controls the hot air at a constant level.
The diode D ₁ D ₂ and the resistor R ₃ are a compensation circuit for stably operating the capacitor C ₁ and the trigger element SBS. A control circuit 9 is constituted by these temperature sensor PTC, triac T, trigger element SBS, capacitor _C1 , etc. The temperature sensor PTC is a positive temperature-resistance thermistor, and functions to limit energization to the heater _H1 when the temperature exceeds a certain temperature. A switch _S2 constituting an air volume adjustment means is provided at both ends of a resistor _R2 that is part of the voltage dividing resistor R, and the resistor _R2 is short-circuited or energized, and the voltage applied to the motor M is switched. The rotation is variable. In addition, changeover switch S ₂ is switched to multiple stages to change resistor R ₂ to R ₂ ′R ₂ ″...
A large number of them may be provided. Capacitor _C2 is used in combination with coil L to prevent radio wave interference. Temperature fuse F is for preventing excessive temperature rise and stops the motor.
This is a safety device in case of circuit abnormality. Next, the operation will be explained. When contact r ₂ of switch S ₁ is opened and contact r ₁ is closed, the voltage rectified by rectifier DM is applied to motor M, cold air is generated, and when switch S ₂ is closed, voltage dividing resistor R is resistance
Since only _R1 is applied, the voltage applied to the motor M increases, resulting in a strong wind condition. Furthermore, when the switch _S2 is opened, the voltage dividing resistor R becomes the sum of the resistors _R1 and _R2 , and the voltage applied to the motor M decreases accordingly, resulting in a weak wind condition. Next, both contacts r ₁ r ₂ of switch S ₁
When both are closed, the triator T is phase-controlled as described above and the heater _H1 is energized to generate hot air, but when the switch _S2 is closed, strong winds are generated.
When S ₂ is open, hot air is generated in a weak wind. At this time, the temperature sensor PTC senses temperature, its internal resistance increases as the temperature rises, and the trigger element
It takes a long time to reach the voltage that makes SBS conductive, which works to limit the power of heater _H1 , which always keeps the air temperature constant. Therefore, even if switch _S2 is changed, a constant air temperature can always be obtained. In addition, if the room temperature in which the hair dryer is used changes, if an attachment is attached to the outlet side for drying or setting, or if foreign matter such as dust acts on the suction port side, the temperature sensor
PTC works to keep the air temperature constant. Also, open both ends of resistor R ₂ with switch S ₂ ,
By simply short-circuiting, the voltage applied to the motor M can be varied, and therefore the air volume can be varied, and the temperature sensor PTC can keep the air temperature constant, so there is no need to switch the heater circuit. Therefore, the entire circuit structure can be made simple. FIG. 5 shows another embodiment, in which two heaters H ₁ H ₂ are connected in series with the triax T, and both heaters
A resistor R is connected between the connection point of H ₁ H ₂ and the rectifier DM, and a switch S ₂ is connected to both ends of the heater H ₂ . Other parts are the same as in FIG. If contact r ₁ of switch S ₁ is closed,
When cold air is generated and switch _S2 is on, the divided voltage applied to motor M is only resistor R, resulting in a strong wind condition. Also, when switch _S2 is turned off, the voltage applied to motor M becomes the divided voltage of the sum of resistor R and heater _H2 , and the voltage applied to motor M decreases by that much, but the resistance value is R
≫Since it is set to H ₂ , strong wind conditions are maintained for most of the time. Here, heater _H2 is energized, but resistance R
is larger than that of heater _H2 , and the air temperature hardly rises in this circuit with only a few tens of watts. next,
When contacts r ₁ r ₂ of switch S ₁ are closed together, heater H ₁
is energized and generates hot air, but when switch S ₂ is on, only heater H ₁ is activated, power supply voltage is applied across both ends of heater H ₁ , and temperature sensor
Controlled by PTC. At this time, strong winds will be controlled. Next, switch
When _S2 is turned off, the heater _H2 is energized, resulting in a circuit as shown in FIG. In other words, heater H ₂ is connected to the parallel circuit of motor circuit A and heater circuit B.
are connected in series, the voltage applied to the motor M is lowered by the heater _H2 , and
Energization to heater _H1 will also be restricted. Therefore, if switch S ₂ is turned off, motor M
The rotational speed of the heater H1 decreases, resulting in a strong wind condition, and the heat generated by the heater _H1 is also limited. In this way, even if the rotation of the motor M is varied by changing the switch _S2 , the air temperature can be kept constant by the temperature sensor PTC. As shown in the figure, by inserting the heater _H2 in series with the heater _H1 , the amount of heat generated by the heater _H1 during weak winds is small, and an abnormal temperature rise can be prevented. By the way, the temperature sensor PTC that detects the wind temperature
is installed in a range of 5 mm to 15 mm from the end face of the wave-shaped heater H ₁ (range C in Figure 2), and a temperature sensor PTC is installed on the projection surface of the heater H ₁ from which hot air is blown. Heater _H1 has better heat detection. When the contacts r ₁ r ₂ of the switch S ₁ are closed, the heater H ₁ is energized and hot air is generated as described above, but at this time, the following characteristics are exhibited regarding the mounting position of the temperature sensor PTC. The distance between heater _H1 and temperature sensor PTC is 5
mm or less, the heat generated by heater _H1 (approximately 200
~300℃), and the temperature sensor PTC deteriorates due to heat. Furthermore, due to the influence of the distribution of the heater _H1 , an error occurs between the temperature detected by the temperature sensor PTC and the temperature of the blown air. The distance between heater _H1 and temperature sensor PTC is 15mm.
With the above, the detection ability of the temperature sensor PTC is good, but the responsiveness when the motor M stops is poor.
The effect of preventing excessive temperature rise disappears. This is shown in Table 1.

〔Effect of the invention〕

As described above, the present invention includes an air volume adjusting means that adjusts the volume of air blown out by rotation of a fan driven by a motor, a temperature sensor that detects the temperature of the air heated by the heater, and a signal from the temperature sensor. and a control circuit that limits the air temperature according to the air volume, so the air volume by the fan can be varied by changing the rotation of the motor using the air volume adjustment means.
Moreover, even if the air volume is variable, the control circuit uses the signal from the temperature sensor to control the air volume, so the air volume can be kept at a constant temperature with high accuracy. It consists of a voltage dividing resistor connected in series to the motor and a shorting switch connected in parallel to this voltage dividing resistor, so by setting the number and value of the voltage dividing resistors appropriately, By varying the voltage applied to the motor, a desired air volume can be easily set in advance without changing other circuits, and even if the air volume is varied, the control circuit can always keep the air temperature constant. It is something.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram of a conventional example, Fig. 2 is a vertical sectional view of a hair dryer according to an embodiment of the present invention, Fig. 3 is a sectional view taken along line XX in Fig. A circuit diagram, FIG. 5 is a circuit diagram of another embodiment same as above,
FIG. 6 is a circuit diagram of the main parts of the same as above, and FIG. 7 is an enlarged perspective view of the temperature sensor same as above. 4 is the fan, PTC is the temperature sensor, H ₁ is the first
heater, _H2 is the second heater, R is the voltage dividing resistor,
S ₁ indicates a switch, and S ₂ indicates a switch.

Claims (1)

[Scope of Claims] 1. Air volume adjusting means for adjusting the volume of air blown out by rotation of a fan driven by a motor; a temperature sensor for detecting the temperature of the air heated by the heater;
A control circuit that receives a signal from a temperature sensor and limits the air temperature according to the air volume is provided, and the air volume adjustment means is connected to a voltage dividing resistor connected in series to the motor, and a voltage dividing resistor connected in parallel to the voltage dividing resistor. A hair dryer comprising a short-circuit switch and a short-circuit switch. 2. The hair dryer according to claim 1, wherein the heater has a first heater and a second heater, and the second heater also serves as the partial pressure resistor.