JPH0457324B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a hair dryer, and more particularly, to a hair dryer, which has a blowing means and a heater in a housing, and the heater partitions the inside of the housing into a plurality of sections to divide the airflow into a plurality of sections. The present invention relates to a hair dryer configured by holding a heating wire on a heater substrate.

[Background technology]

Generally, a hair dryer is provided in which a temperature sensing element is installed in the housing to detect the temperature of the hot air, and the temperature of the heater is adjusted via a control circuit so that the hot air is maintained at a substantially constant temperature. Therefore, it is desirable for this type of hair dryer to be equipped with a temperature sensing element so that changes in the temperature of the hot air can be detected sensitively. However, conventional hair dryers simply have a temperature sensing element inside the housing, and sufficient consideration has not been given to making it easier to detect temperature changes. Furthermore, since it is difficult to obtain a completely uniform laminar flow within the housing, the temperature sensing element must detect a representative value within the housing. However, when using an axial flow fan, hot air flows through the housing. Because it moves in a spiral, there are areas that are more likely to be exposed to hot air and areas that are less likely to be exposed to hot air, and this determines the location of the temperature sensing element and components that make up the control circuit. It is necessary.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned problems, and its main purpose is to enable the temperature sensing element to quickly respond to changes in the temperature of the heater. The purpose of
The spiral flow of hot air created by the axial fan improves the airflow to the temperature sensing element, and
The objective is to arrange the thermosensor and the components of the control circuit so that the components of the control circuit do not obstruct the flow of warm air to the thermosensor.

[Disclosure of the invention]

Embodiments of the present invention will be described below based on the drawings. The hair dryer according to the present invention includes a housing 1
and a blowing means 4 which pressurizes air taken in from an inlet 2 provided at one end of the housing 1 and discharges it from an outlet 3 provided at the other end of the housing 1.
, a heater 5 that heats the air flow created in the housing 1 by the air blower 4, and a control circuit that detects the temperature of the hot air inside the housing 1 and maintains the hot air at a substantially constant temperature. A temperature sensing element 7 for controlling the temperature of the heater 5 via a portion 6,
The heater 5 has heating wires provided on a heater board 8 that divides a part of the airflow into a plurality of parts within the housing 1, and each section inside the housing 1 divided by the heater board 8 is connected to the heater 5. The heating wires 9 are placed in each section so that the heating wires 9 face each section.
The distribution ratio of the heating wire 9 facing each section is set so that the amount of heating per unit flow rate of the airflow passing through one section is larger than that of the other sections, and the unit flow rate is This is characterized in that the temperature sensing element 7 is disposed within the section where the amount of heating per unit is maximum.

The housing 1 has a cylindrical shape, and has an inlet port 2 opening at its rear end in the axial direction, and a discharge port 3 opening at its front end. A power line 20 extends from the center of the rear end of the housing 1 . Inside the housing 1, there is an axial fan 10 and a drive source 1 for the axial fan 10.
1 and a motor, and the air blowing means 4 blows the air into the housing
A heater 5 and the like that heats the air flow generated from the air toward the discharge port 3 are housed. Axial flow fan 1
0 rotates around the axis of the housing 1, pressurizes the air taken into the housing 1 through the suction port 2, creates an air flow along the axial direction of the housing 1, and discharges it from the discharge port 3. Motor 1
1 is an axial flow fan 1 in the axial direction of the housing 1
It is placed after 0. A rectifier blade 21 is provided around the motor 11, and the rectifier blade 21 rectifies the spiral flow of air produced by the axial fan 10 so that it approaches a laminar flow along the axial direction of the housing 1. The rectified airflow passes through a heater 5 disposed at the end of the discharge port 3 in the axial direction of the housing 1 and is heated there.
As shown in FIG. 4, heating wires 9 are provided on a heater substrate 8 having a substantially cross-shaped cross section and arranged radially around the axis of the housing 1. As shown in FIG. The heater substrate 8 is a heat-resistant insulating substrate such as mica,
Of the vertical and horizontal pieces, the horizontal piece extends rearward, and the vertical piece extends forward. The heating wire 9 is a resistance wire bent into a zigzag shape or a coil spring shape, and faces into each section in the housing 1 partitioned by the heater board 8. Each section,
, , a temperature sensing element 7 is disposed at the front end of the housing 1 in the axial direction. The temperature sensing element 7 is disposed within the compartment on the front end side in the direction of rotation of the axial fan 10, so that the temperature sensing element 7 faces the wind direction of the spiral flow created by the axial fan 10. Its shape allows it to be well exposed to warm air. Further, in the section where the temperature sensing element 7 is provided, the total length of the heating wire 9 is longer than in the other sections. In other words, in this section, other sections,
, the pitch of the coils is denser than that of other sections, ,
, the heating amount per unit flow rate for the air flow is larger than that of the heating wire 9 of . This temperature sensing element 7 is a PTC-like element, and the control circuit section 6
It is connected to the heater 5 via.

As shown in FIG. 3, the control circuit section 6 includes a switch element T for phase control such as a triax, a trigger element SBS such as a silicon bidirectional switch,
and a capacitor _C1 as basic components. The temperature sensing element 7 is a positive temperature-resistance element having a positive temperature-resistance characteristic, and the capacitor C ₁
connected in series. Temperature sensing element 7 and capacitor C ₁
The series circuit is connected in parallel to both poles of the switch element T, and the gate terminal of the switch element T and the temperature sensing element 7 are connected in parallel to both poles of the switch element T.
A trigger element SBS is connected between the capacitor C1 and the connection portion of the capacitor _C1 . One of the two poles of the switch element T is connected to the power supply line 20 via the coil L wound around the toroidal core and the switches SW ₁ and SW ₂ , and the other pole is connected to the temperature fuse F ₁ , the heater 5, and It is connected to the other side of the power supply line 20 through a series circuit of an ordinary fuse _F2 . Therefore,
Capacitor C ₁ is charged through temperature sensing element 7,
When this reaches a predetermined value, a gate signal is applied from the trigger element SBS to the gate terminal of the switch element T, and the switch element T becomes conductive. When the switch element T becomes conductive, the capacitor _C1 is discharged, and when the switch element T is turned off, it is charged again through the temperature sensing element 7. However, when the temperature of the hot air increases and exceeds a predetermined value, the resistance value of the temperature sensing element 7 increases, the time required to charge the capacitor _C1 becomes longer, and the time until the trigger element SBS becomes conductive becomes longer. As a result, the conduction period of the switch element T becomes longer and the amount of power supplied to the heater 5 becomes smaller. In this way, by controlling the amount of power supplied to the heater 5 according to the temperature of the hot air, the temperature of the hot air is kept substantially constant. In the figure, diodes D ₁ , D ₂ and resistor R ₁ constitute a compensation circuit for stably operating capacitor C ₁ and trigger element SBS, respectively. Coil L is varistor ZNR and capacitor
Together with C ₂ , it constitutes a noise prevention circuit or radio interference prevention circuit. This coil L is wound on the toroidal core 22 and has an excellent noise prevention effect. One end of the coil L is connected to the power supply line 20 via a first switch SW ₁ and a second switch SW ₂ connected in series, and one end of the varistor ZNR and capacitor C ₂ are connected between both switches SW ₁ and SW ₂ . Connected. The other ends of the varistor ZNR and the capacitor C ₂ are connected to the other side of the power supply line 20 . barista
A motor drive circuit section is connected in parallel to the parallel circuit of ZNR and capacitor _C2 . The motor drive circuit is a diode bridge DB, a capacitor _C3 ,
C ₄ , voltage dividing resistor R ₂ , and air volume adjustment switch SW ₃
Consists of. Therefore, if the first switch SW ₁ and the second switch SW ₂ are closed simultaneously, the motor 1
1 and heater 5 are energized to obtain hot air, and the first
If only the switch SW ₁ is closed, only the motor 11 is driven and cold air can be obtained. The voltage dividing resistor R ₂ is provided with a tap TT.
and one end of the voltage dividing resistor _R2 .
SW ₃ is provided. Therefore, by opening and closing the air volume adjustment switch SW ₃ , the partial pressure resistance R ₂
The resistance value at both ends changes. As a result, the motor 11 connected to the output end of the diode bridge DB
The terminal voltage changes as the air volume adjustment switch SW ₃ is opened and closed, and as a result, the rotational speed of the motor 11 changes, making it possible to vary the air volume.

The circuit components and temperature-sensing element 7 constituting the control circuit section 6, motor drive circuit section, etc. described above are divided into four sections divided by a heater board 8, as shown in FIGS. 4 to 6. , can be stored in . Most of the circuit components are arranged on a mounting board 23 fixed to the rear end of the heater board 8, and among these circuit components, large components are arranged in a section different from that of the temperature sensing element 7. Ru. By not arranging other large components in the section where the temperature sensing element 7 is arranged in this way, the air blow resistance in that section is reduced, making it easier for hot air to hit the temperature sensing element 7, and as a result. , the temperature sensing element 7 can quickly detect temperature changes in the hot air.

〔Effect of the invention〕

As described above, the present invention divides the air flow path in the housing by the heater substrate that holds the heating wire of the heater, and arranges the temperature sensing element in one of the divided sections. , the amount of heating per unit flow rate by the heat-generating wire for the airflow passing through the section where the temperature-sensing element is located is greater than that in other sections, so the heat-generating wire in the section where the temperature-sensitive element is installed is less sensitive to changes in current. This results in a larger change in the amount of heat generated by the heat-generating wires than in other sections, and as a result, there is an advantage that the response of the temperature-sensitive element to changes in the current flowing through the heat-generating wires is improved. In other words, it is possible to increase the amount of change in the output value of the temperature sensing element in response to changes in the current flowing through the heating wire, making it possible to control the amount of heat generated by the heating wire with good responsiveness without using a highly sensitive temperature sensing element. This has the effect of making it possible. In addition, in a dryer having an axial fan as a blowing means, in which the temperature sensing element is disposed at the front end in the rotational direction of the axial fan within the compartment, the direction of the spiral flow generated in the housing by the axial fan The thermosensing elements face each other, and the hot air strongly hits the thermosensing elements, which has the advantage that the temperature of the hot air can be detected efficiently. Furthermore, most of the components of the control circuit that controls the amount of current to the heater in response to the temperature sensing element are housed in a section partitioned by the heater board where the temperature sensing element is not placed. This has the advantage that hot air can reach the temperature sensing element within the section where the temperature sensing element is disposed without being obstructed by other parts, and as a result, the temperature of the hot air can be detected with high sensitivity. As mentioned above, the temperature sensing element can sensitively detect the amount of heat generated by the heater and the temperature of the hot air.
The temperature of the hot air can be accurately maintained at a substantially constant value.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway front view showing one embodiment of the present invention, FIG. 2 is a plan view of the same, FIG. 3 is a circuit diagram showing a control circuit section and a motor drive circuit section used in the same, and FIG. The figure is a sectional view taken along the line X-X in Figure 2.
The figure is a partial sectional view taken along the line Y-Y in Figure 4, and Figure 6 is a partial cross-sectional view of the line Y-Y in Figure 4.
It is a partial sectional view taken along the Z-Z line in the figure. 1 is the housing, 2 is the suction port, 3 is the discharge port, 4
5 is a blower means, 5 is a heater, 6 is a control circuit section, 7 is a temperature sensing element, 8 is a heater board, 9 is a heating wire, 10 is an axial flow fan, 11 is a drive source, . . . is a partition.

Claims (1)

[Scope of Claims] 1. A housing, a blowing means for pressurizing air taken in from an inlet provided at one end of the housing, and discharging it from an outlet provided at the other end of the housing; A heater heats the airflow created within the housing, and a sensor that detects the temperature of the hot air inside the housing and controls the temperature of the heater via a control circuit so that the hot air is maintained at a substantially constant temperature. The heater has a heating wire held on a heater board that partitions the inside of the housing into a plurality of sections and divides a part of the air flow into a plurality of sections. The heating wires are distributed to each section so that the heating wires face each section, and each section is arranged so that the amount of heating per unit flow rate of the airflow passing through one section is larger than that of other sections. A hair dryer characterized in that the temperature-sensitive element is disposed within a section where the distribution ratio of the facing heating wires is set and the amount of heating per unit flow rate is maximized. 2. The air blowing means is composed of an axial fan and a drive source that rotationally drives the axial fan, and the temperature sensing element is configured to rotate in the direction of rotation of the axial fan within one of the plurality of compartments partitioned by the heater board. The hair dryer according to claim 1, wherein the hair dryer is disposed at the front end portion of the hair dryer. 3. Claim No. 3, characterized in that the components constituting the control circuit section are disposed in a section other than the section in which the temperature sensing element is disposed among the plurality of sections divided by the heater board. The hair dryer according to item 1.