JPS63270004A - Hair dryer - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a hair dryer.

[Prior Art] Hair dryers that are held in the hands of users have traditionally controlled the phase of a commercial frequency voltage to set the amount of electricity, supplied it to a heater that heats air, and rectified it. It is known that the heated air is supplied to a DC motor and a suitable amount of heated air is blown by a fan attached to the DC motor. Such a hair dryer can finely adjust the noise level by finely setting the amount of power through phase control.

[Problems to be Solved by the Invention] However, the phase-controlled voltage is a pulsating voltage as shown in FIG. 3(E), and its peak value voltage is high and its rise is steep. For this reason, when the DC motor is rotating at high speed and current switching occurs between the rotating commutator of the DC motor and the brushes that are in contact with it, a large arc current flows.

As a result, the contact surfaces of the brushes gradually wear out, and over long periods of use, incomplete contact between the commutator and the brushes results in failure. Therefore, when using it for a long time,
Readjustments and parts replacement were necessary as appropriate. In contrast to such brushed DC motors, brushless DC motors that do not use brushes have recently been put into practical use, but driving them requires a complicated control circuit around them, so they are not suitable for use with simple hair dryers. Not commonly used.

Another possibility is to provide the hair dryer with a smoothing circuit such as a transformer, a choke coil, or a capacitor in order to make the voltage applied to the DC motor a sufficiently smooth voltage with small ripples, but this method is lightweight. It cannot be incorporated into such a required hair dryer and is not a practical solution.

Therefore, an object of the hair dryer of the present invention is to reduce the wear on the brush surface of the DC motor that drives the fan by a simple means and to improve its durability.

[Means for Solving the Problems] In order to achieve the above object, the hair dryer of the present invention includes a DC motor that has a brush and a commutator and drives an air blowing fan, and a DC motor that drives the air blown by the fan. In a hair dryer equipped with a heater for heating and a rectifier circuit that rectifies commercial alternating current using a rectifying element and supplies it to the DC motor, a capacitance component commensurate with the ripple of electric power is added between the brushes of the DC motor.

The rectifier circuit may have a circuit configuration that performs either half-wave rectification or full-wave rectification.

[Operation] The hair dryer of the present invention rectifies commercial alternating current using a rectifier circuit and supplies it to a direct current motor, which drives a fan to blow air heated by a heater. The ripple portion of the electric power supplied to the DC motor is reduced by the corresponding capacity component.

[Example] A preferred example of the present invention will be described. Figure 1 is the first
FIG. 2 is a circuit diagram showing the configuration of the phase control circuit of the hair dryer according to the embodiment, and FIG. 2 is a side view showing the shape of the hair dryer.

As shown in FIG. 2, the case 2 of the hair dryer 1 is made of an abbreviated heat-resistant resin, and includes a sirocco fan (not shown), a DC motor M1° that drives the sirocco fan, a heater H1, A phase control circuit 11 is housed therein. Moreover, a button-type instant cooling switch S2 is provided above the grip part 2a that is held when using the hair dryer 1, and allows switching between hot and cold air by simply pressing with the index finger. A changeover switch S1 that can be switched by sliding is provided. This changeover switch S1 has 5 steps, rOFF
The positions of J, rLJ, rMj, rHJ, and rsHJ can be set.

Roughly speaking, a hook 3 made of highly elastic synthetic resin and a power cord 4 are attached to the bottom of the grip 2a. A large number of circular rectangular openings 2b are formed on both sides of the hair dryer 1.

The outside air sucked in through the opening 2b is heated inside the hair dryer 1 and blown out through the discharge port 2C. A groove 2d is formed around the case 2 on the side of the discharge port 2C to which an attachment such as a throttle (not shown) is attached.

Next, the DC motor M1, the heater 11, and the phase control circuit 11 for driving and controlling these, which are housed in the case 2, will be explained.

As shown in Figure 1, the heater H uses commercial AC as a power source.
1. Phase control circuit 11. The power line that supplies power to the DC motor M1 has a changeover switch S1. Capacitor C1 that absorbs noise during switching and interlocking fuse F that cuts off the power line when abnormal temperature occurs
is provided. The heater H1 includes a thermostat T that cuts off power supply to the heater H1 when the temperature of the heater H1 becomes abnormally high due to thermal runaway.
H is provided. Further, the DC motor M1 is supplied with electric power that has been bridge rectified by a bridge rectifier D1.

A capacitor C3 is installed between the brushes of the DC motor M1, and a phase compensation resistor R4 is installed between the commercial AC side terminals of the bridge rectifier D1.

In addition, DC motor M] is '100 [V], 300 [m
A] The brush is of a standard that rotates at a standard value of 5000 [ROM] upon receiving electric power, and its brush is made of carbon. Capacitor C3 is 56 in this example.
It is an electrolytic capacitor with a capacity of [μF]. Also, resistor R4
is a carbon resistor with a resistance value of 7.5 [KΩ] and a large R power consumption of 2 [W].

Next, the phase control circuit 11 will be explained. The phase control circuit 11 includes a gate trigger circuit 12 and a triac circuit 1.
It consists of 3. The gate trigger circuit 12 includes a four-stage variable resistor VR2 whose resistance value is switched in conjunction with switching of the changeover switch S1, a semi-fixed resistor R1 for adjustment connected in parallel to this, a double resistor VRI, A time constant circuit consisting of a fixed resistor R2 and a capacitor C2 connected in series to VR2, and a diac DIA whose one end is connected to the capacitor C2 and whose other end is the output terminal of the gate trigger circuit 12.
C, and a hysteresis removal circuit consisting of a resistor R1 and diodes D2 and D3. In this gate trigger circuit 12, when the voltage charged in the capacitor C2 exceeds the threshold value of the diac DfAC, the diac DIA
C becomes conductive and the voltage charged in the capacitor C2 is outputted to the output terminal as a trigger pulse via the diac DIAC. Therefore, by switching the four-stage variable resistors V and R2, the charging time of the capacitor C2 changes and the timing of the trigger pulse can be varied.

The i~liac circuit 13 to which the output of the gate trigger circuit 12 is input is important to connect the bridge rectifier D1 of the DC motor M1 and the power line]・DIAC TRIA
C1, and a triac TRIAC2 which is important for connection between the heater H1 and the power supply line. The gate terminal of this triac TRIACI is
connected to the output terminal of The gate terminal of the triac TRIAC2 to which the quick cooling switch S2 is connected is connected to the diode D4. It is connected to one end of the heater H1 via a resistor R3, and also to the output terminal of the diac DIAC via a switching diode SD. Therefore, when the instant cooling switch S2 is turned off, the TRIAC
The gate terminal of No. 2 becomes open.

The operation of such a hair dryer 1 will be explained. When the changeover switch S1 is set to the rHJ position, the phase control circuit 11 connected to the AC power supply controls the power supplied to the heater H1 and the DC motor M1, and the hair dryer 1
This will be explained in detail. Figure 3 shows
It is a timing chart which shows the voltage waveform of each part when changeover switch S1 is set to the position rl-1j.

As shown in the figure, in the phase control circuit 11 to which a sinusoidal waveform power supply voltage (broken line in Fig. 3 (A)) is applied, the variable resistor VR
The capacitor C2 is charged at a predetermined time constant involving 2, and the terminal voltage of the capacitor C2 becomes a small voltage with an amplitude delayed in phase with respect to the power supply voltage (solid line in FIG. 3(A)). When this voltage exceeds the threshold of the diac DIAC, the diac DIAC turns on and the diac DIAC
A trigger pulse is generated at the output terminal of the capacitor C2 as the capacitor C2 is discharged (FIG. 3(B)). When the generation of the trigger pulse is finished, the diac DIAC is turned off again, but the triac TRIAC1 is turned on by this trigger pulse, and the connection between the power supply line and the bridge rectifier D1 is made conductive. Then, when the supply voltage crosses a voltage level close to zero volts, the triac TRIAC1 is turned off again and the connection is broken. The above operations are repeated depending on the period of the power supply voltage, and as a result, a voltage with a waveform chopped at a predetermined phase is applied between the input terminals of the bridge rectifier D1, as shown in FIG. 3(C). . When the voltage with such a waveform is bridge rectified by the bridge rectifier D1 and smoothed by the capacitor C3, or when the flywheel current is absorbed, it becomes a voltage close to DC with a waveform as shown in FIG. 3(D). Therefore, the voltage applied to the DC motor M1 is as follows when the capacitor C3 is not provided:
Compared to the applied voltage of a conventional DC motor (FIG. 3(E)), this voltage has a lower peak value and has less ripple.

By the way, in the hair dryer 1 of this embodiment, even if the changeover switch S1 is changed to each position of "rLJ, rMJ, rHJ, and Ist 1" to change the amount of air blown, the temperature of the blown air remains lower than that of the direct current equipped with the sirocco fan. The temperature of the heater H1 is constant regardless of the characteristics of the motor M1 and the heater H1.
The change in the power control amount is made gentler than that of the DC motor M1. In other words, when the trigger pulse output from the DIAC is positive, phase control is performed on the DC motor M1 [-Similar to the RIAC TR'IAC1, 1 to TRIAC2 are also turned on and the heating heater H is turned on.
However, when it is negative, the trigger pulse is blocked by the switching diode SD, so in this case, the triac TRIAC2 is always turned on by the forward current flowing through the resistor R3 and the diode D4, and the heating heater []1 It energizes. Therefore, since the triac TRfAC2 performs phase control only during one half-wave period, the change in the power control amount to the heater H1 is smaller than the change in the power control amount to the DC motor M1.

As shown above, according to the hair dryer 1 of this embodiment,
Since the ripple component of the voltage applied between the brushes of the DC motor M1 is reduced, it is possible to reduce the wear of the brushes that occurs between the brushes and the commutator that is in contact with the commutator and rotates at high speed. Therefore, the durability time of the DC motor M1 that drives the sirocco fan is improved. For example, in this embodiment, the durability time was 1200 hours when the capacitor C3 was not used, but it was 2200 hours.
The hair dryer can now be used for up to 2,700 hours, which is more than twice as long, allowing users to use the hair dryer for up to 2,700 hours without having to readjust or replace parts.
can be suitably used for a long period of time. Also, capacitor C
3, the power supplied to DC motor M1 (3rd
The figure (D>hatched) is increased.

Next, another embodiment of the hair dryer of the present invention will be described. FIG. 4 is a circuit diagram showing only the main parts related to the control of the hair dryer of another embodiment. The hair dryer of this embodiment switches the temperature to two levels by setting the selector switch S4 to the "LQWJ" and "rHIGHJ" positions.In this embodiment, the axial flow fan (
A capacitor C5 is attached between the brushes of a DC motor M2 to which a motor (not shown) is attached. Changeover switch S4
When set from the rOFFJ position to the rHIGHJ position, the commercial AC is supplied to the heater H2 via thermistor THI, bridge rectified by the bridge rectifier D7, smoothed by the capacitor C5, and then supplied to the DC motor M2.
supplied to When the selector switch S4 is switched from the rHIGHj position to the rLOWJ position, the commercial alternating current is converted into only one half wave by the rectifier diode D6, and is supplied to the 0-power thermal heater H2 and the DC motor M2 as in the case of rHIGHJ.

In this way, according to the hair dryer of this embodiment, as in the first embodiment, the capacitor C5 installed between the brushes of the DC motor M2 reduces the ripple, so wear on the brush surface is reduced, and adjustment and parts replacement are possible. A hair dryer can be used for a long time without the need for a hair dryer. Further, the amount of power supplied to the DC motor M2 can be easily increased by increasing the capacitance d value by charging and discharging the capacitor C5.

[Effects of the Invention] According to the hair dryer of the present invention, it is possible to suppress the pulsating component of the current flowing through the brushes of the DC motor to the commutator with an extremely simple configuration, so it is possible to reduce the wear of the brushes of the DC motor. be effective.

Therefore, the durability of the hair dryer can be improved by at least twice as much, and even when used for a long time, it is possible to blow air at the right temperature.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram of the hair dryer of the embodiment, Fig. 2 is a front view showing the shape of the hair dryer, Fig. 3 is a timing chart showing the signal waveforms of each part, and Fig. 4 shows only the main parts of the embodiment. FIG. 1...Hair dryer Ml, M2...DC motor 1
1... Phase control circuit C3, C5... Capacitor 1
2... Gate trigger circuit 13... Triac circuit

Claims (1)

[Scope of Claims] A DC motor that has brushes and a commutator and drives a fan for blowing air, a heater that heats the air blown by the fan, and a DC motor that rectifies commercial alternating current with a rectifier. and a rectifier circuit for supplying power to the DC motor, wherein a capacitance component commensurate with the ripple of the electric power is added between the brushes of the DC motor.