Hair dryer

Abstract

To provide a hair dryer that blows a warm wind with stable warmth irrespective of difference in voltage of AC power at home and abroad and can be preferably used.SOLUTION: A hair dryer 1 includes: a heating part 120; and a controller 100 for controlling supply power to be supplied to the heating part 120. The controller 100 repeatedly switches a duty ratio of the supply power every predetermined time in accordance with input voltage.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a hair dryer. [Background technology]

[0002] Patent Document 1 discloses a conventional hair dryer. This hair dryer is equipped with a control unit that controls the power supplied to the heating element. This control unit varies the phase difference between the timing at which the voltage waveform of the supplied power rises from 0V and the timing at which power starts to be supplied to the heating element, depending on the input voltage from the AC power source. In other words, this control unit varies the duty ratio, which is the ratio of how long the power is on in the voltage cycle of the supplied power, depending on the input voltage. This allows this hair dryer to supply power to the heating element regardless of differences in AC power source voltages both in Japan and overseas. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-34259 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the hair dryer in Patent Document 1 sets one phase difference for each input voltage and supplies power to the heating unit. This makes it difficult to finely adjust the power supplied to the heating unit. Also, since this hair dryer starts supplying power to the heating unit at a high voltage, there are concerns that it may affect other devices.

[0005] The present invention has been made in consideration of the above-mentioned conventional situation, and aims to provide a hair dryer that can be used satisfactorily by blowing hot air with a stable temperature, regardless of differences in AC power voltages both domestically and internationally. [Means for solving the problem]

[0006] The hair dryer of the present invention comprises a heating unit and a control unit that controls the power supplied to the heating unit, and the control unit repeatedly switches the duty ratio of the power supply at predetermined time intervals in accordance with an input voltage.

[0007] This hair dryer repeatedly switches the duty ratio of the power supplied to the heating section by the control unit at predetermined time intervals depending on the input voltage, thereby suppressing changes in power consumption in the heating section and thereby suppressing changes in the hot air temperature.

[0008] Therefore, this hair dryer can be used effectively, blowing hot air with a stable temperature, regardless of the difference in AC power voltage between Japan and overseas. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 2 is a right side view showing the hair dryer of Example 1 with the grip portion extended. [Figure 2] FIG. 2 is a right side view showing the hair dryer of Example 1 with the grip part folded. [Figure 3] 1 is a block diagram showing the configuration of a hair dryer according to a first embodiment. [Figure 4] 10A and 10B are diagrams showing voltage waveforms of supplied power with duty ratios of 100%, 75%, and 66%. [Figure 5] This is a graph showing the relationship between input voltage and power consumption, where (A) shows the case where power is supplied to the heating unit with one duty ratio depending on the input voltage, and (B) shows the case where power is supplied to the heating unit with two duty ratios repeatedly switched at predetermined time intervals depending on the input voltage. [Figure 6] FIG. 10 is a right side view showing the hair dryer of Example 2 with the grip portion extended. DETAILED DESCRIPTION OF THE INVENTION

[0010] A preferred embodiment of the present invention will now be described.

[0011] In the hair dryer of the present invention, the power supply of at least one of the duty ratios can be turned on / off only when the voltage is near 0V. In other words, at least one of the duty ratios is either 75% or 66%. In this case, the power supply to the heating element is turned on / off only when the voltage is near 0V. Therefore, this hair dryer can reduce the impact on other devices when supplying power to the heating element. "Near 0V" here means 0V±20V.

[0012] The control unit of the hair dryer of the present invention can change the supply time of the power of each duty ratio to the heating unit. In this case, by changing the supply time of the power of each duty ratio to the heating unit, the power supplied to the heating unit can be precisely controlled. Therefore, this hair dryer can suppress changes in power consumption in the heating unit and therefore changes in the hot air temperature.

[0013] The control unit of the hair dryer of the present invention can change the supply time of the power having a smaller duty ratio to the heating unit among the plurality of duty ratios. In this case, by changing the supply time of the power having a smaller duty ratio to the heating unit, the power supplied to the heating unit can be more precisely controlled than when changing the supply time of the power having a larger duty ratio to the heating unit. Therefore, the hair dryer can suppress changes in the power consumption of the heating unit and thereby suppress changes in the hot air temperature.

[0014] Example 1 Next, a first embodiment of a hair dryer according to the present invention will be described with reference to the drawings. For ease of explanation, the air outlet 11 side of the air duct 10 is referred to as the front, the air inlet 13 side as the rear, the side where the handle 30 extends from the air duct 10 as the bottom, and the opposite side as the top, and the left and right sides in a front view from the front are referred to as the left and right. In the three-dimensional Cartesian coordinate system shown in each figure, the positive direction of the X axis is the "front direction," the negative direction of the X axis is the "rear direction," the positive direction of the Y axis is the "upward direction," the negative direction of the Y axis is the "downward direction," the positive direction of the Z axis is the "leftward direction," and the negative direction of the Z axis is the "rightward direction."

[0015] <Structure of Hair Dryer 1> As shown in FIGS. 1 and 2, the hair dryer 1 of the first embodiment includes an air channel 10, a handle 30, a first operating unit 51 to a third operating unit 53, and a power cord 70. The air channel 10 is cylindrical and extends in the front-to-rear direction. The air channel 10 has an air outlet 11 at its tip. The air outlet 11 is coated with ceramic that emits far-infrared rays. Various nozzles, such as a setting nozzle (not shown), can be detachably attached to the air outlet 11 of the air channel 10. The air channel 10 has an air inlet 13 at its rear end. The air inlet 13 is formed by a cover member with multiple slits extending horizontally. The air inlet 13 extends from the rear end surface of the air channel 10, wrapping around the left and right sides of the air channel 10. The air inlet 13 has a vertical width that is approximately 4 / 5 of the rear edge of the air channel 10, and the vertical width decreases toward the front when viewed from the right side. The suction port 13 is curved so as to bulge outward.

[0016] The grip portion 30 has an upper grip portion 30A and a lower grip portion 30B, with a sliding surface 31 as the boundary. The upper grip portion 30A is continuous with the underside of the air duct 10 on the side of the inlet port 13. The lower grip portion 30B is connected to the underside of the upper grip portion 30A. The sliding surface 31 slopes downward from the front end to the rear end. The lower grip portion 30B rotates clockwise and counterclockwise relative to the upper grip portion 30A around a rotation axis perpendicular to the sliding surface 31. The grip portion 30 transforms into an extended state and a folded state by the rotation of the lower grip portion 30B. The extended state of the grip portion 30 is a state in which the upper grip portion 30A and the lower grip portion 30B extend in a straight line, as shown in FIG. 1. When the grip portion 30 is extended, the outer peripheral surface of the upper grip portion 30A and the outer peripheral surface of the lower grip portion 30B are flush. When the grip portion 30 is extended, it is inclined forward from the upper end to the lower end. When extended, the grip portion 30 is approximately cylindrical. When extended, the middle portion of the grip portion 30 is slightly thicker than the upper and lower ends. When the grip portion 30 is extended, the grip portion 30 is folded by rotating the lower grip portion 30B counterclockwise relative to the upper grip portion 30A. The folded state of the grip portion 30 is when, as shown in FIG. 2, the lower grip portion 30B extends approximately parallel to the extension direction of the air channel portion 10, forming a space between the air channel portion 10 and the lower grip portion 30B into which the user's fingers can be inserted. When the gripping part 30 is in the folded state, the gripping part 30 is extended by rotating the lower gripping part 30B clockwise relative to the upper gripping part 30A. When changing the gripping part 30 between the extended state and the folded state, the direction in which the lower gripping part 30B is rotated relative to the upper gripping part 30A is not limited to the rotation direction described above, and for example, the gripping part 30 may be rotated in the opposite direction to the rotation direction described above.

[0017] As shown in Figure 1, the gripping part 30 is provided with a cord bushing 33 that extends downward and is continuous with the lower end of the lower gripping part 30B. The cord bushing 33 has a hook part 35 at the upper front part. The power cord 70 passes through the cord bushing 33 and is continuous with the lower end of the lower gripping part 30B. The power cord 70 has a power plug (not shown) at its tip.

[0018] As shown in FIG. 1, the first operating unit 51 is located at the top of the front surface of the lower gripping unit 30B, in the center from left to right, when the gripping unit 30 is extended. The first operating unit 51 is a switch that slides up and down along the front surface of the lower gripping unit 30B. The first operating unit 51 is positioned at any of the bottom, middle, and top positions. The bottom position of the first operating unit 51 is the "OFF" position, the middle position is the "COOL" position, and the top position is the "HOT" position. When the first operating unit 51 is positioned at "OFF," the hair dryer 1 is powered off and is in a stopped state. When the first operating unit 51 is positioned at "COOL," the hair dryer 1 blows cool air at room temperature (hereinafter referred to as "cool air") from the air outlet 11 without supplying power to the heating unit 120 (described later). When the first operating unit 51 is positioned at "HOT," the hair dryer 1 supplies power to the heating unit 120 to blow hot air from the air outlet 11. Control of the power supplied to the heating unit 120 will be described later. In other words, the first operating unit 51 can start and stop the hair dryer 1 and switch between hot and cold air.

[0019] As shown in FIGS. 1 and 2, the second operating unit 52 and the third operating unit 53 are arranged side by side in the front-to-rear direction on the right side of the air tunnel 10, above the portion where the upper grip portion 30A is continuous. The second operating unit 52 and the third operating unit 53 are push buttons in the shape of a long, narrow rectangle that is long in the front-to-rear direction. The second operating unit 52 is a mode button that alternates between "HIGH mode" and "LOW mode" each time it is pressed. "HIGH mode" is an air blowing mode in which, of the two types of air strength, air with a higher air volume and air speed is blown from the air outlet 11. "LOW mode" is an air blowing mode in which, of the two types of air strength, air with a lower air volume and air speed is blown from the air outlet 11. In other words, the second operating unit 52 can switch the air strength. When the first operating unit 51 is positioned at either "HOT" or "COOL," the wind tunnel unit 10 displays the word "MODE" in white (not shown) above the second operating unit 52. When the first operating unit 51 is positioned at "OFF," the part of the wind tunnel unit 10 where the word "MODE" is displayed is a mirrored surface, and the word "MODE" cannot be seen from the outside.

[0020] This hair dryer 1 blows air in "HIGH mode" when the first operating unit 51 is moved from the "OFF" position to the "COOL" position to start the hair dryer 1, or when the first operating unit 51 is moved from the "OFF" position past the "COOL" position to the "HOT" position to start the hair dryer 1. When the first operating unit 51 is moved between the "COOL" position and the "HOT" position, this hair dryer 1 continues to blow air in the previous air mode.

[0021] The third operation unit 53 is a sensing button that functions when the first operation unit 51 is positioned at "HOT." The third operation unit 53 does not function when the first operation unit 51 is positioned at "COOL." When the first operation unit 51 is positioned at "HOT," the wind tunnel unit 10 displays the word "SENSE" above the third operation unit 53 in white light (not shown). When the first operation unit 51 is positioned at either "OFF" or "COOL," the part of the wind tunnel unit 10 where the word "SENSE" is displayed is a mirrored surface, and the word "SENSE" cannot be seen from the outside.

[0022] There are two sensing programs: "SCALP" and "MOIST." Each time the third operating unit 53 is pressed, the sensing program switches between "OFF," "SCALP," and "MOIST." When the "SCALP" sensing program is selected and executed, the hair dryer 1 controls the output of the heating unit 120 based on the outside air temperature in either the "HIGH mode" or "LOW mode" air blowing mode, and blows hot and cold air alternately from the air outlet 11 so that the object temperature is within 50°C ± 5°C. When the "MOIST" sensing program is selected and executed, the hair dryer 1 controls the output of the heating unit 120 based on the outside air temperature in either the "HIGH mode" or "LOW mode" air blowing mode, and blows hot and cold air alternately from the air outlet 11 so that the object temperature is within 60°C ± 5°C. When the sensing program is off, the hair dryer 1 blows hot air at 80°C to 90°C from the air outlet 11 in either the "HIGH mode" or "LOW mode." In other words, the third operating unit 53 can turn the sensing program of the hair dryer 1 on and off, and switch between programs.

[0023] As shown in FIG. 3, the hair dryer 1 includes an air blower 110, a heater 120, an ion generator 130, a display 140, a voltage detector 150, a temperature detector 160, and a controller 100, all of which are provided in an air tunnel 10. The air blower 110 is located at the rear end of the air tunnel 10. The air blower 110 includes a motor and a fan. The motor is a small, lightweight brushless DC motor. The motor is driven at a high rotation speed of 100,000 rpm or more. This allows the hair dryer 1 to blow strong air with high speed and pressure from the air blower 110. The motor is driven and controlled by PWM (Pulse Width Modulation) control.

[0024] The heating unit 120 is disposed at the front end of the air tunnel 10. The heating unit 120 heats the air sent from the air blower 110. The heating unit 120 has a first heating wire and a second heating wire made of nichrome wire or the like. The first heating wire has an electrical resistance of 10 Ω, and the second heating wire has an electrical resistance of 38.5 Ω. When the input voltage of the heating unit 120 is 130 V or less, power is supplied only to the first heating wire. When the input voltage of the heating unit 120 is greater than 130 V, power is supplied to the first and second heating wires connected in series.

[0025] The ion generating unit 130 ionizes molecules in the air. In this hair dryer 1, the ions generated by the ion generating unit 130 are combined with far infrared rays emitted from the ceramic coating on the air outlet 11 to reach the user's hair, suppressing static electricity in the hair and leaving the hair moisturized.

[0026] The display unit 140 is provided on the right side of the air tunnel unit 10. The right side of the air tunnel unit 10 on which the display unit 140 is provided is a mirror surface when viewed from the outside when the power plug is not inserted into an outlet, and when the power plug is inserted into an outlet and the first operating unit 51 is in the "OFF" position, turning the power off. The display unit 140 displays the state of the air blown from the air tunnel unit 10 (air direction, hot air / cold air, and air strength) when air is being blown from the air blower unit 110 (not shown). The user can intuitively grasp the state of the air from the display on the display unit 140.

[0027] The voltage detection unit 150 detects the input voltage from the AC power supply. The temperature detection unit 160 includes a first temperature sensor and a second temperature sensor. Each temperature sensor is configured with an NTC thermistor. The first temperature sensor is disposed inside the air tunnel 10, between the blower 110 and the heater 120. The first temperature sensor measures the temperature of the air drawn in through the air inlet 13 (outside air temperature). The second temperature sensor is disposed at the front end of the air tunnel 10. The second temperature sensor measures the internal temperature at the front end of the air tunnel 10.

[0028] The control unit 100 is disposed within the air tunnel 10, between the blower 110 and the heater 120. The control unit 100 includes a control board (not shown) and a plurality of electronic components mounted on the control board. The control unit 100 controls the motor of the blower 110, the power supplied to the heater 120, the drive of the ion generator 130, and the display on the display unit 140, in response to operation signals generated by the operations of the first to third operation units 51 to 53, voltage signals generated by the voltage detected by the voltage detector 150, and temperature signals generated by the temperature detected by the temperature detector 160.

[0029] <Relationship between input voltage and duty ratio> As shown in Table 1, the control unit 100 repeatedly switches the duty ratio of the power supplied to the heating unit 120 at predetermined time intervals in accordance with the input voltage from the AC power supply detected by the voltage detection unit 150. Voltage waveforms of power supply with duty ratios of 100%, 75%, and 66% are shown in Figures 4(A), (B), and (C), respectively. The supply current with duty ratios of 75% and 66% is turned on / off only when the voltage is near 0V.

[0030] [Table 1]

[0031] As shown in Table 1, this hair dryer 1 continuously supplies power to the first heating wire at a duty ratio of 100% when the input voltage is between 90V and 106V. This hair dryer 1 alternately supplies power to the first heating wire at a duty ratio of 100% for 0.5 seconds and a duty ratio of 66% for 0.2 seconds when the input voltage is between 108V and 110V. This hair dryer 1 alternately supplies power to the first heating wire at a duty ratio of 100% for 0.5 seconds and a duty ratio of 66% for 0.4 seconds when the input voltage is between 112V and 114V. In this way, the control unit 100 of this hair dryer 1 alternately switches the duty ratio between 100% and 66% at predetermined time intervals depending on the input voltage of 108V to 114V. Furthermore, the time for which power having a duty ratio of 66%, which is the smallest of these duty ratios, is supplied to the first heating wire is changed from 0.2 seconds to 0.4 seconds.

[0032] When the input voltage is between 116V and 120V, this hair dryer 1 supplies power to the first heating wire at a duty ratio of 75% for 0.5 seconds and a duty ratio of 66% for 0.4 seconds, alternating between these two. When the input voltage is between 122V and 130V, this hair dryer 1 supplies power to the first heating wire at a duty ratio of 75% for 0.5 seconds and a duty ratio of 66% for 0.6 seconds, alternating between these two. In this way, the control unit 100 of this hair dryer 1 repeatedly switches the duty ratio between 75% and 66% at predetermined intervals depending on the input voltage between 116V and 130V. Furthermore, the control unit 100 changes the duration for which power with the smaller duty ratio, 66%, is supplied to the first heating wire from 0.4 seconds to 0.6 seconds.

[0033] This hair dryer 1 supplies power with a duty ratio of 100% continuously to the first and second heating wires connected in series when the input voltage is 132V to 228V. This hair dryer 1 supplies power with a duty ratio of 100% for 0.5 seconds and power with a duty ratio of 66% for 0.2 seconds, alternatingly, to the first and second heating wires connected in series when the input voltage is 230V. This hair dryer 1 supplies power with a duty ratio of 100% for 0.5 seconds and power with a duty ratio of 66% for 0.4 seconds, alternatingly, to the first and second heating wires connected in series when the input voltage is 232V to 240V. This hair dryer 1 supplies power to the first and second heating wires connected in series, with an input voltage of 242V to 250V, by alternately switching between a 100% duty cycle supply for 0.5 seconds and a 66% duty cycle supply for 0.6 seconds. This hair dryer 1 supplies power to the first and second heating wires connected in series, with an input voltage of 252V to 260V, by alternately switching between a 100% duty cycle supply for 0.5 seconds and a 66% duty cycle supply for 0.8 seconds. This hair dryer 1 supplies power to the first and second heating wires connected in series, with an input voltage of 262V to 270V, by alternately switching between a 100% duty cycle supply for 0.5 seconds and a 66% duty cycle supply for 1.0 second. When the input voltage is 272V, this hair dryer 1 alternately supplies power to the first and second heating wires connected in series with a duty ratio of 100% for 0.5 seconds and then with a duty ratio of 66% for 1.2 seconds. In this way, the control unit 100 of this hair dryer 1 repeatedly switches the duty ratio between 100% and 66% at predetermined intervals depending on the input voltage, which ranges from 230V to 272V. Furthermore, the duration for which power with the smaller duty ratio of 66% is supplied to the first and second heating wires connected in series is sequentially changed as follows: 0.2 seconds, 0.4 seconds, 0.6 seconds, 0.8 seconds, 1.0 second, and 1.2 seconds.

[0034] As shown in Figure 5(B), the drop in power consumption of this hair dryer 1 is smaller at input voltages of 100V to 120V and 200V to 240V than the drop in power consumption of the comparative example shown in Figure 5(A). When the change in power consumption of the heating unit 120 is small, the change in temperature of the warm air heated by the heating unit 120 is small and stable. Because the change in temperature of the warm air is small and stable at input voltages of 100V to 120V and 200V to 240V, this hair dryer 1 can blow warm air with a stable warmth and can be used satisfactorily regardless of differences in AC power voltages both domestically and internationally.

[0035] <Relationship between input voltage and duty ratio in comparative example> The hair dryer of the comparative example supplies power to the heating unit 120 at one duty ratio depending on the input voltage. Specifically, when the input voltage is 90V to 108V, power at a duty ratio of 100% is continuously supplied to the first heating wire. When the input voltage is 110V to 124V, power at a duty ratio of 75% is continuously supplied to the first heating wire. When the input voltage is 126V to 130V, power at a duty ratio of 66% is continuously supplied to the first heating wire. When the input voltage is 132V to 228V, power at a duty ratio of 100% is continuously supplied to the first and second heating wires connected in series. When the input voltage is 230V to 272V, power at a duty ratio of 75% is continuously supplied to the first and second heating wires connected in series.

[0036] As described above, the hair dryer 1 of Example 1 includes the heating unit 120 and the control unit 100 that controls the power supplied to the heating unit 120, and the control unit 100 repeatedly switches the duty ratio of the power supply at predetermined time intervals according to the input voltage.

[0037] In this hair dryer 1, the control unit 100 repeatedly switches the duty ratio of the power supplied to the heating unit 120 at predetermined time intervals depending on the input voltage, thereby suppressing changes in the power consumption in the heating unit 120 and thereby suppressing changes in the hot air temperature.

[0038] Therefore, this hair dryer 1 can blow hot air with a stable temperature regardless of the difference in AC power voltage between Japan and overseas, and can be used satisfactorily.

[0039] In the hair dryer 1 of Example 1, the power supply with duty ratios of 75% and 66% is turned on / off only when the voltage is near 0 V. Therefore, this hair dryer 1 can reduce the influence on other devices when supplying power to the heating unit 120.

[0040] The control unit 100 of the hair dryer 1 of Example 1 changes the supply time of power having a small duty ratio of 66% to the heating unit 120 among a plurality of duty ratios. In this way, by changing the supply time of power having a small duty ratio to the heating unit 120, it is possible to more precisely control the power supplied to the heating unit 120. Therefore, the hair dryer 1 can suppress changes in the power consumption of the heating unit 120 and suppress changes in the hot air temperature.

[0041] <Example 2> As shown in Fig. 6, the hair dryer 2 of Example 2 differs from the hair dryer 1 of Example 1 in the shape of the rear end of the air channel 20. The other configurations are the same as those of Example 1, and the same configurations are denoted by the same reference numerals and detailed description thereof will be omitted.

[0042] The rear end of the air tunnel 20 of this hair dryer 2 has a rear edge that slopes forward from the bottom to the top when viewed from the right side. The air inlet 23 is provided at the rear end of the air tunnel. The air inlet 23 is formed by a cover member with multiple horizontally extending slits. The air inlet 23 extends from the rear end face of the air tunnel 20, wrapping around the left and right sides of the air tunnel 20. The air inlet 23 has a width that is approximately 4 / 5 of the rear edge of the air tunnel 20. The air inlet 23 is curved so that the central upper and lower portions are concave inward. Thus, the upper and lower ends of the rear end of the air tunnel 20 protrude outward beyond the air inlet 23. Therefore, when the rear end of the air tunnel 20 comes into contact with another object, the air inlet 23 is less likely to come into contact with the object and is less likely to be damaged.

[0043] The present invention is not limited to the first and second embodiments described above with reference to the drawings, and the following embodiments are also included within the technical scope of the present invention. (1) The control unit may switch the duty ratio between three values ​​of 100%, 75%, and 66% at predetermined time intervals in accordance with the input voltage. (2) The control unit may switch between two duty ratios, 100% and 75%, at predetermined time intervals depending on the input voltage. (3) The time for which the power of each duty ratio is supplied to the heating unit may be different from that in the first embodiment. (4) Of the multiple duty ratios, the time for which power having a larger duty ratio is supplied to the heating section may be changed. (5) If the ON / OFF of the power supply is near 0V, the duty ratio may be around 75% or 66%. (6) The duty ratio may be a value other than 100%, 75%, or 66%. (7) The heating unit may have three or more heating wires. In this case, the power supply may be switched between the heating wires, and the duty ratio of the power supply may be changed depending on the switching of the heating wires. [Explanation of symbols]

[0044] 1,2...Hair dryer 100...Control unit 120...Heating part

Claims

1. A heating unit; a control unit that controls the power supplied to the heating unit; It is equipped with The control unit repeatedly switches the duty ratio of the supplied power at predetermined time intervals in accordance with an input voltage.

2. 2. The hair dryer according to claim 1, wherein the supply power of at least one of the duty ratios is turned on / off only when the voltage is near 0V.

3. The hair dryer according to claim 1 or 2, wherein the control unit changes the supply time of the power of each duty ratio to the heating unit.

4. 3. The hair dryer according to claim 1, wherein the control unit changes the supply time of the power having a smaller duty ratio among the plurality of duty ratios to the heating unit.

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