JPWO2008129662A1 - Hot air generator and hand dryer using the same - Google Patents

Abstract

The hot air generator according to one aspect of the present invention aims to heat air extremely efficiently and with high responsiveness. This hot air generator includes an induction coil made of a conductive material and at least one object to be heated disposed adjacent to the induction coil. In addition, the hot air generator includes a power source that supplies a high-frequency current to the induction coil, an outer frame that forms at least one flow path between the heated body, and a flow path within the flow path to heat the heated body. A blower that forms an air flow. In this way, the air in the flow path can be heated very efficiently and with high responsiveness.

Description

  The present invention relates to a hot air generator and a hand dryer using the same, and more particularly to a hot air generator employing a heating method using electromagnetic induction and a hand dryer using the same.

  Hand dryers are widely used in toilets used by many people such as public facilities and offices as a device for hygienically drying hands after washing. The hand dryer uses a warm air type that blows warm air with a low wind speed from a wide outlet and evaporates water droplets attached to the hand after washing, and a high air flow (jet stream) from a small nozzle. There is a jet type that blows off water droplets that erupt and adhere to the hand. Furthermore, some jet-type hand dryers reduce the time to dry the hands and remove the air squirting using a heater in order to eliminate the user's discomfort caused by exposure to a cold jet stream. Those that are preheated are commercially available. Thus, a heater for heating air is widely used in both hot air type and jet type hand dryers.

  For example, a conventional hand dryer disclosed in Patent Document 1 generally has a heating device having an intake port and an air supply port, and a suction port connected to the air supply port of the heating device. Air is sucked from the intake port of the heating device and heated by the heating device by the high-pressure airflow generator disposed in the hand drying device body, and the hand drying device body Inhaled (see especially FIG. 1).

  In the hand-drying device of Patent Document 1, the heating device includes a sheathed heater and a heat storage and radiation fin made of aluminum metal having a large specific heat that is in close contact with the sheathed heater. The sheathed heater generates heat when power is supplied while the user is not using the hand dryer, that is, while the high pressure airflow generator is not operating. The heat from the sheathed heater is stored in the heat storage and radiation fins, and the air heated through the heat storage and radiation fins is stored in the heating device. When the user uses the hand dryer, the power supply to the sheathed heater is stopped and the high-pressure airflow generator is activated, so that the heated air stored in the heater is stored in the hand dryer main body. While being sucked in, the air sucked from the intake port of the heating device is sequentially heated through the heat storage and radiation fins and is similarly supplied into the main body of the hand dryer.

  Moreover, in the hand dryer of patent document 2, the PTC (Positive Temperature Coefficient) heater which has another heating mechanism is provided between the high-speed blower and blowing nozzle as a ventilation means. When the sensor detects that the user's hand has been inserted into the processing space of the hand dryer, the high speed blower and the PTC heater are supplied with power, and the air sucked from the suction port of the hand dryer is supplied with the high speed blower and Heated via the PTC heater, warm air is blown from the ejection nozzle. When the user retracts his / her hand from the processing space, the high speed blower and the PTC heater are stopped.

  Furthermore, the hand drying device described in Patent Document 3 includes a flat heater disposed in the vicinity of the air intake, and the flat heater includes ceramics or metal having a thermal conductivity of 50 W / m · K or more. And a resistance heating element having a thickness of 5 mm or less provided thereon. When the sensor detects that the user's hand has been inserted into the hand insertion section of the hand dryer, the flat heater and the blower, which is a high-pressure air flow generator, are activated, and the air flow flowing in from the air intake is flat. It is heated by the heater.

  Further, according to Patent Document 4, a hand washing and drying apparatus is disclosed in which a warm washing mist is ejected from a duct to wash a hand, and then a hand is dried by supplying a high-speed air flow. In this manual washing and drying apparatus, it is taught that a high-frequency induction heater, an electric heater, a ceramic heater, or a gas heater can be adopted as a heating means for heating the cleaning mist. Further, it is described that another high-frequency induction heater, an electric heater, a ceramic heater, or a gas heater can be used as means for heating the high-speed air flow to a predetermined temperature of, for example, 50 to 80 ° C. However, Patent Document 4 does not describe or suggest any specific configuration of these heating means.

JP-A-10-75915 JP 2006-187435 A JP 2005-34272 A JP 2000-60763 A

  In the hand dryer described in Patent Document 1, as described above, the heat from the sheathed heater supplied during standby when the high-pressure airflow generator is not operating is stored in the heat storage and radiation fins, and the heat storage and radiation fins. The air heated via is stored in the heating device. That is, when the high-pressure airflow generator is operating, power supply to the sheathed heater is stopped. Therefore, since the power required to drive the high-pressure airflow generator and the power required to heat the sheathed heater are not supplied at the same time, there is no need to increase the power supply capacity of the hand dryer, Since it is necessary to continuously supply power to the sheathed heater of the heating device even during standby, there is a problem that power consumption during standby cannot be suppressed.

  In addition, since the heated air is already stored in the heating device before the hand drying device is used, warm air is blown out as soon as the hand drying device is used, which is extremely comfortable for the user. It is. However, when this hand dryer is used very frequently, the time of the operation state becomes longer than the standby state of the hand dryer, it becomes impossible to accumulate a sufficient amount of heat in the standby state, and the temperature of the jet airflow decreases. There was a problem.

  Furthermore, a sheathed heater generally has a heat generating conductor coated with an insulator, and since air is heated through an insulator heated by the heat generating conductor, the thermal resistance from the heat generating conductor to the air is large. That is, it is inferior to thermal conductivity. Therefore, it is necessary for a hand dryer using a sheathed heater to accumulate sufficient heat in a large volume of heated air or heat storage and radiation fins, and to protect the components of the hand dryer main body from a high temperature heating device. For this reason, it is necessary to provide a heating device that is separate from the main body of the hand dryer, which is a factor that hinders downsizing of the hand dryer.

  According to the hand dryer disclosed in Patent Document 2, when a user inserts a hand into the processing space of the hand dryer, power is supplied to both the high-pressure airflow generator and the PTC heater, and the PTC heater is in standby mode. Therefore, there is an advantage that the power consumed by the PTC heater during standby can be reduced. However, since the resistance value of the PTC heater changes depending on the temperature, the resistance value of the PTC heater increases especially when exposed to the wind of a high-speed blower, and sufficient power is not supplied to the PTC heater, and it is continuously used. As it was, the temperature of the warm air tended to decrease.

  Further, as described above, the hand dryer described in Patent Document 3 has a resistance heating element provided on a ceramic or metal substrate having high thermal conductivity, and the temperature of the air flow is similar to that of a PTC heater. Even if power is supplied to the heater at the same time as the operation of the blower, which is a high-pressure airflow generator, without change, the heater is heated in 1 to 2 seconds, and warm air at 70 ° C is stabilized within 2 to 3 seconds. Can be supplied. However, for this purpose, it is necessary to sufficiently increase the surface area of the flat heater, but there is a problem that the production cost is high because the structure of the flat heater is complicated.

  Patent Document 4 suggests a hand washing and drying apparatus using a high-frequency induction heater, an electric heater, a ceramic heater, or a gas heater as a means for heating a cleaning mist or a high-speed air stream. It does not describe or suggest any specific structure and usage of the heating means.

  A hot air generator according to one aspect of the present invention includes an induction coil made of a conductive material, at least one heated body disposed adjacent to the induction coil, and heating the heated body. A power source that supplies a high-frequency current to the induction coil, an outer frame that forms at least one flow path between the object to be heated, and a blower that forms an air flow in the flow path. The air is heated by the object to be heated.

  According to the hot air generator according to one aspect of the present invention, by supplying a high-frequency current, a heated body disposed adjacent to the induction coil is heated, and the heated body flows through the flow path. Since it is in direct contact with the air, it is possible to heat the air very efficiently and responsively.

It is a side view which shows the hand-drying apparatus by Embodiment 1 which concerns on this invention. FIG. 3 is a perspective view showing a specific structure of the IH heater according to the first embodiment. It is the expansion perspective view which expanded a part shown with the broken line of FIG. FIG. 3 is a circuit wiring diagram of the IH heater according to the first embodiment. (A) is a perspective view which shows the specific structure of the heating coil of Embodiment 1, (b) is the front view, (c) is sectional drawing seen from the VC-VC line of FIG.5 (b). . It is a drive circuit diagram for supplying a high frequency current to a heating coil. It is a wave form diagram which shows the alternating current supplied to a heating coil. It is sectional drawing cut | disconnected by the XY plane of the IH heater of Embodiment 2. FIG. It is an exploded view of one heater cell of the IH heater shown in FIG. It is sectional drawing similar to FIG. 8, Comprising: The conductive wire is wound twice. It is the same exploded view as FIG. 9, Comprising: The conductive wire is wound twice. FIG. 6 is a cross-sectional view of the IH heater according to Embodiment 3 cut along the XY plane. FIG. 13 is an exploded view of one heater cell of the IH heater shown in FIG. 12. FIG. 10 is a cross-sectional view of an IH heater according to a modification of the third embodiment. It is sectional drawing cut | disconnected by the XY plane of the IH heater of Embodiment 4. FIG. FIG. 16 is an exploded view showing a part of the IH heater shown in FIG. 15. FIG. 10 is a cross-sectional view of an IH heater according to a modification of the fourth embodiment. FIG. 10 is a cross-sectional view of an IH heater according to another modification of the fourth embodiment. FIG. 10 is a perspective view of an IH heater according to a fifth embodiment. FIG. 10 is a perspective view of an IH heater according to a modification of the fifth embodiment. FIG. 10 is a cross-sectional view taken along the XY plane of an IH heater according to another modification of the fifth embodiment. It is a partially broken perspective view of the IH heater shown in FIG. It is sectional drawing cut | disconnected by the XY plane of the metal plate and metal tube by the modification of Embodiment 1-5. It is a side view which shows the hand-drying apparatus by Embodiment 6. FIG. 25 is a partially enlarged view of the housing including the ejection nozzle shown in FIG. 24. It is a graph which shows the time-dependent change of the temperature of a sheathed heater, the temperature of the jet air current to be ejected (ejection temperature), and the temperature of the outside air to be inhaled (intake air temperature) regarding a conventional hand dryer using a sheathed heater. Regarding the conventional hand dryer using a sheathed heater, the difference between the intake air temperature and the jet temperature (temperature rise) changes during the 10 seconds of operation after the first heat treatment and during the first, fifth and 60th operation. It is a graph which shows a mode. It is the same graph as FIG. 26 at the time of supplying a high frequency current regarding the hand dryer of this invention which employ | adopted the IH heater using a SUS430 stainless steel plate. It is the same graph as FIG. 27 at the time of supplying a high frequency current regarding the hand dryer of this invention which employ | adopted the IH heater using a SUS430 stainless steel plate. It is the same graph as FIG. 26 at the time of supplying a high frequency current regarding the hand-drying apparatus of this invention which employ | adopted the IH heater using a SUS304 stainless steel plate. It is the same graph as FIG. 27 at the time of supplying a high frequency current regarding the hand-drying apparatus of this invention which employ | adopted the IH heater using a SUS304 stainless steel plate. It is the same graph as FIG. 26 at the time of supplying a direct current regarding the hand-drying apparatus of this invention which employ | adopted the IH heater using a SUS430 stainless steel plate. It is the same graph as FIG. 27 at the time of supplying a direct current regarding the hand-drying apparatus of this invention which employ | adopted the IH heater using a SUS430 stainless steel plate. It is a graph which shows the relationship between IH electric power ratio and the difference (temperature rise) of intake air temperature and ejection temperature. It is the graph which plotted the average temperature of the surface of the stainless steel plate of an IH heater when an operation | movement and a stop are repeated 60 times after pre-heat processing. It is a graph which shows the relationship between IH electric power ratio and reserve electric power.

Explanation of symbols

1: hand dryer, 2: housing, 3: high-pressure air generator (blower), 4: induction heater (IH heater), 5: control circuit, 6: air inlet, 7: outlet (spout nozzle), 8 : Duct, 9: manual insertion space, 10: outer frame, 12: opening, 14: heater cell, 16: wiring board, 17: wiring terminal, 18: external terminal, 20: heating coil (induction coil), 22: terminal , 23: substrate, 24: metal thin film (conductive layer), 25: polypropylene resin film, 26: glass epoxy resin film, 27: through-hole, 28: terminal, 30: metal plate (object to be heated), 31: IGBT element 32: FWD element, 33: gate control signal, 34: power supply, 36: rectifier circuit, 38: metal tube (heated body), 40: flow path, 42: insulating coating conductive wire, 44: support, 50: hollow Metal tube (object to be heated), 52: flat surface, 5 : Through fixture 55: fixing means, 56: spacer, 60: metal tube (hollow conductor), 64: magnetic shield plate

  Hereinafter, an embodiment of a hand dryer according to the present invention will be described with reference to the accompanying drawings. In the description of the embodiments below, terms representing directions (for example, “X direction”, “Y direction”, “Z direction”, “upward”, “downward”, etc.) are used as appropriate for easy understanding. These are for illustration purposes only, and these terms do not limit the invention. Moreover, in each accompanying drawing, the same component is illustrated using the same referential mark.

Embodiment 1 FIG.
FIG. 1 is a side view showing a hand drying device 1 according to Embodiment 1 of the present invention. The hand-drying apparatus 1 of Embodiment 1 is roughly divided into a housing 2, a blower 3 that is a high-pressure air generator that generates high-pressure air, and induction heating that is an induction heating apparatus (Induction Heating Apparatus) for heating the air. A heater (hereinafter simply referred to as “IH heater”) 4 and a control circuit 5 for controlling the blower 3 and the IH heater 4 are provided.

  The housing 2 includes an intake port 6 for taking in ambient air, a plurality of jet ports (spout nozzles) 7 for jetting air heated by the IH heater 4 to the outside, and a space between the intake port 6 and the jet port 7. And a duct 8 (broken line in FIG. 1) in fluid communication. The IH heater 4 and the blower 3 are disposed in a duct 8, and the duct 8 communicates with a flow path of the IH heater 4 described later. The housing 2 forms a hand insertion space 9, where the user's hand can be dried by the jet stream ejected from the jet outlet 7, and whether the user's hand has been inserted into the hand insertion space 9. A hand sensor (not shown) for detecting whether or not is provided is provided. The hand sensor may be any suitable sensor apparent to those skilled in the art, such as infrared LEDs and photodiodes, and is configured to communicate with the control circuit 5.

  In the hand dryer 1 configured as described above, when the hand sensor detects that the user's hand has been inserted into the hand insertion space 9, the hand sensor transmits a detection signal to the control circuit 5, and the control circuit 5 And the IH heater 4 is operated. When the blower 3 and the IH heater 4 are operated, the ambient air is sucked into the duct 8 from the intake port 6 as shown by the arrows in FIG. 1, and the air in the flow path communicating with the duct 8 is heated by the IH heater 4. Then, the heated air is jetted from the jet port 7 as a jet stream through the branched duct 8. Similarly, when the hand sensor stops detecting the user's hand, the control circuit 5 controls the IH heater 4 and the blower 3 to stop.

  The jet stream ejected from the ejection nozzle 7 has a wind speed of 50 to 120 m / s and blows off water droplets adhering to the user's hand. Also, since the jet stream is heated by the IH heater 4, even when the ambient air temperature is low, the user is not uncomfortable, the evaporation of water droplets attached to the hand is promoted, and the drying time is shortened. can do. The temperature of ambient air is detected using a temperature sensor (not shown), and the control circuit 5 may be configured to control the output of the IH heater 4 so as to reach a predetermined temperature of the jet stream that the user feels comfortable with. Good.

  2 is a perspective view showing a specific structure of the IH heater 4 according to Embodiment 1, and FIG. 3 is an enlarged perspective view of a part indicated by a broken line in FIG. As shown in FIG. 2, the IH heater 4 includes an outer frame 10 having an opening 12 penetrating in the Z direction, and a plurality (15 in FIG. 1) arranged substantially parallel to the YZ plane. And a heater cell 14. As shown in FIG. 3, each heater cell 14 includes a heating coil (induction coil) 20 and a pair of metal plates (objects to be heated) 30 sandwiching the heating coil (induction coil). FIG. 3 does not show the right metal plate 30 of the heater cell 14 shown on the rightmost side. At this time, a plurality of flow paths 40 extending in the Z direction are formed between the metal plate 30 of the adjacent heater cell 14 and the outer frame 10 (not shown in FIG. 3). The housing 2 communicates with the intake port 6 and the jet port 7.

  When a high frequency current is supplied via the control circuit 5, the heating coil 20 receives an alternating current to form a high frequency magnetic field, and the metal plate 30 generates heat due to an eddy current generated internally by the high frequency magnetic field. Since the heated metal plate 30 is in direct contact with the air flowing in the flow path 40, the air can be heated extremely efficiently and with high responsiveness.

  As described above, when the blower 3 is activated, a high-speed air flow is formed in the flow path 40 between the heater cells 14, and when the high-frequency current is supplied to the heating coil 20, the metal plate 30 generates heat and the metal plate 30 is heated. The air in the facing channel 40 is heated. The width of each flow path 40 (interval between adjacent heater cells 14) needs to be designed so that the pressure loss does not increase and the wind speed of the airflow does not decrease. In the IH heater 4 of this embodiment, about 1 mm to 5 mm. , Preferably about 3 mm.

  The heating coil 20 is made of an arbitrary conductive material, but is electrically insulated from the metal plate 30. The heating coils 20 of the three adjacent heater cells 14 are connected in parallel, and one terminal 22a in FIG. 3 is connected to a wiring terminal 17a above the wiring board 16 attached on the outer frame 10 shown in FIG. The other terminal 22 b is connected to a wiring terminal 17 b below the wiring board 16. In addition, the plurality of wiring terminals 17a and 17b of the wiring board 16 are connected in series, and the IH heater 4 includes five sets of three heating coils 20 connected in parallel as shown in the circuit diagram of FIG. They are wired in series and are electrically connected to the control circuit 5 via the external terminals 18a and 18b.

  More specifically, as shown in FIGS. 5A to 5C, the heating coil 20 according to the first embodiment has a spiral shape made of a substrate 23 made of glass epoxy resin and a metal such as copper thereon. And a thin film (conductive layer) 24 patterned. Further, the heating coil 20 has a polypropylene resin film 25 and a glass epoxy resin film 26 on the metal thin film 24 in order to be electrically insulated from the metal plate 30 and thermally protected (FIG. 5C). The metal thin film 23, the polypropylene resin film 25, and the glass epoxy resin film 26 are preferably formed on both surfaces of the substrate 23 and efficiently heat a pair of metal plates 30 that sandwich the heating coil 20 (polypropylene resin). The film 25 is not hatched to make the drawing easier to understand.) At this time, in FIG. 5C, the metal plating processed through hole 27 is provided in the vicinity of the center of the substrate 23 and the metal thin film 24 so that the metal thin films 24 provided on both surfaces of the substrate 23 are electrically connected to each other. Is provided. Thus, current flows from the terminal 28a provided on the front surface side of the substrate 23 to the metal thin film 24, the through hole 27, the metal thin film 24 on the back surface side, and the terminal 28b. The metal thin films 24 provided on both surfaces of the substrate 23 are patterned so that their spiral directions are opposite to each other (clockwise and counterclockwise) in order to match the direction of the magnetic field to be formed. Yes.

  Although not limited to this, the size of the metal plate 30 may be 60 mm × 60 mm × 0.6 mm, and the substrate 23 of the heating coil 20, the metal thin film 24, the polypropylene resin film 25, and the glass epoxy resin film. The thickness of 26 may be 400 μm, 105 μm, 100 μm and 100 μm, respectively.

  The material constituting the metal plate 30 may be any material as long as it is heated by the heating coil 20, but is preferably a stainless steel plate, and in particular, specified by JIS (Japanese Industrial Standard) standards. The stainless steel plate SUS430 is particularly preferable because it hardly corrodes, has high magnetic permeability, and is inexpensive. In addition, the metal plate 30 may be an iron plate, a silicon steel plate, a nickel plate, a permalloy plate, and the like, and the iron plate and the silicon steel plate are useful because they are inexpensive and have high magnetic permeability. It is preferable to perform surface treatment by plating or coating a non-corrosive metal having a high conductivity.

  When the surface treatment is performed, the metal plate 30 such as an iron plate that generates heat by electromagnetic induction heating does not directly contact the fluid passing through the flow path 40. However, if the thickness of the metal plating or coating is sufficiently thin Does not adversely affect thermal conductivity. Similarly, a resin having a small thermal conductivity may be coated on the metal plate 30 such as an iron plate. The metal plate 30 may be a nonmagnetic metal such as a nonmagnetic stainless steel plate, a copper plate, or an aluminum plate. Even in the case of a nonmagnetic material, the metal plate 30 can be heated by appropriately adjusting the driving conditions such as increasing the frequency. it can.

  FIG. 6 is a drive circuit diagram for supplying a high-frequency current to the heating coil 20. The heating coil 20 is represented by an equivalent circuit of an inductance Ls and a resistance Rs connected in series, and corresponds to a portion surrounded by a broken line in FIG. As described above, the IH heater 4 may be configured using a plurality of heating coils 20, and the inductance Ls and the resistance Rs represent the entire inductance and resistance of the plurality of heating coils 20 of the IH heater 4. Shall. The heating coil 20 constitutes an LC resonance circuit together with a capacitor C1 connected in parallel to this, and includes an IGBT (Insulated Gate Bipolar Transistor) element 31 and an FWD (Free Wheel Diode) element 32 connected in parallel in opposite directions. Connected in series. A current from a normal household power supply 34 (AC voltage: 100 V or 200 V) is rectified into a DC current by a rectifier circuit (AC / DC converter) 36 such as a diode bridge, and the DC current is smoothed by a capacitor C2. The direct current supplied to the heating coil 20 does not necessarily need to be smoothed, and the heating coil 20 may be directly supplied with power from a full-wave rectified or half-wave rectified power source (not shown) or a direct-current power supply.

  The IGBT element 31 is switched on and off by a rectangular wave gate control signal 33 from the control circuit 5. When the IGBT element 31 is in the ON state, the direct current from the rectifier circuit 36 and the capacitor C2 is supplied to the heating coil 20, that is, flows through the inductance Ls, the resistor Rs, and the IGBT element 31. When the IGBT element 31 is in the OFF state, the inductance Ls keeps flowing current, so that current flows in the closed loop including the capacitor C1 and charges the capacitor C1. Then, the voltage of the capacitor C1 rises, the current flowing through the inductance Ls decreases, and the discharge current from the capacitor C1 eventually flows in the opposite direction to the inductance Ls and the resistor Rs. Thereafter, when the IGBT element 31 is switched to the ON state again, a forward current flows through the inductance Ls and the resistor Rs. By repeating the switching operation of the IGBT element 31, a sawtooth AC current as shown in FIG. 7 can be passed through the heating coil 20. As described above, the heating coil 20 receives an alternating current to form a high-frequency magnetic field, and the metal plate 30 generates heat due to an eddy current generated internally by the high-frequency magnetic field. Since the metal plate 30 that has generated heat is in direct contact with the air in the flow path 40 to be heated, the air can be heated extremely effectively and with high responsiveness.

  The drive signal input to the IGBT element 31 includes the inductance Ls and resistance Rs of the heating coil 20 used, the capacitance of the capacitor C1, the oscillation frequency, the power supply voltage, the expected output heat amount of the IH heater 4 and the circuit configuration. It can adjust suitably based on these. In other words, the drive condition of the IGBT element 31 can be adjusted according to the expected output heat amount of the IH heater 4. For example, as shown in FIG. 4, in an IH heater 4 configured by connecting five sets of three adjacent heating coils 20 connected in parallel, the inductance Ls of each heating coil 20 is 33 μH and the resistance Rs is 3 mΩ. When the capacitance of the capacitor C1 is 0.3 μF, the oscillation frequency is 20 kHz (period 50 μs), the ON time of the drive signal input to the IGBT element 31 is 37 μs, and the OFF time is 13 μs, the power supply voltage 100 V is used. Thus, power consumption (output heat amount) of about 1 kW can be obtained. The power consumed by the IH heater 4 can be adjusted by controlling the DC voltage output from the rectifier circuit 36. Preferably, the OFF time of the IGBT element 31 is fixed and the ON time is adjusted. Can be easily controlled.

  Note that the drive circuit of the IH heater 4 is not limited to this, and a half-bridge circuit or a full-bridge circuit may be used, and drive circuits used in various induction heating apparatuses can be used.

Embodiment 2. FIG.
A second embodiment of the hand dryer according to the present invention will be described with reference to FIGS. Since the hand dryer 1 of Embodiment 2 is the same as that of Embodiment 1 except for the structure of the IH heater 4, the description of the overlapping contents is omitted.

  FIG. 8 is a cross-sectional view of the IH heater 4 according to the second embodiment cut along the XY plane, and FIG. 9 is an exploded view of each heater cell 14. As in the first embodiment, the IH heater 4 shown in FIG. 9 includes an outer frame 10 having an opening 12 that penetrates in the Z direction, and four heater cells 14 arranged substantially parallel to the YZ plane. Have. Each heater cell 14 includes a heating coil (induction coil) 20 and a pair of metal plates (heated bodies) 30 that sandwich the heater coil 14. Each heating coil 20 is connected in series and driven by the control circuit 5. The number of heater cells 14 is not limited to four, and an arbitrary number of heater cells 14 may be connected in series. Moreover, you may connect the group which connected the some heater cell 14 in parallel like Embodiment 1 in series (for example, 5 sets) in series.

  The flow path 40 of the second embodiment is formed between the adjacent heater cells 14 and the frame 10 as in the first embodiment, and the interval between the adjacent heater cells 14 is about 1 mm to 5 mm, preferably about 3 mm. The heating coil 20 is formed substantially parallel to the YZ plane.

  However, each heating coil 20 of the second embodiment is different from the first embodiment in that, as shown in FIGS. 8 and 9, between the pair of metal plates 30, a conductive wire 42 coated with an insulating film is provided as a heater cell. After extending to the center of 14, it is formed by winding around it. Any conductive wire 42 coated with an insulating film can be used, but an enameled wire or a formal wire may be used.

  Moreover, in order to insulate the heating coil 20 and the metal plate 30 reliably, you may provide the insulating sheet or space which is not shown in figure. Furthermore, the metal plate 30 may be formed using a metal material such as iron, copper, or aluminum in addition to stainless steel, as in the first embodiment.

  In general, electric power consumed by the IH heater 4 (heater cell 14) according to the present invention is converted into Joule heat (Hc) generated from the heating coil 20 itself and Joule heat (Hm) generated from the metal plate 30. Here, if the ratio {Hm / (Hc + Hm)} of the Joule heat (Hm) generated in the metal plate 30 to the total Joule heat (Hc + Hm) is defined as the IH power ratio, the IH power ratio is the resistance value (Rc) of the heating coil 20. ) And the resistance value {Rm / (Rc + Rm)} represented by the resistance value (Rm) of the metal plate 30. That is, in order to suppress Joule heat (Hc) generated from the heating coil 20 itself as much as possible and maximize Joule heat (Hm) generated in the metal plate 30 to efficiently heat the fluid in the flow path 40, the IH power ratio Alternatively, it is necessary to appropriately design the heating coil 20 and the metal plate 30 so that the resistance ratio {Rm / (Rc + Rm)} is as large as possible.

  As described above, when the heating coil 20 is formed by winding the conductive wire 42 coated with an insulating film, the cross-sectional area of the conductive wire 42 is easily increased and the resistance value of the heating coil 20 is decreased. be able to. On the other hand, in order to reduce the resistance value of the heating coil 20 according to the first embodiment, it is necessary to form the metal thin film 24 thick, but such a metal thin film 24 is difficult to process. Therefore, the heating coil 20 according to the second embodiment can heat the air in the flow path 40 more efficiently by using a simpler configuration than that of the first embodiment and increasing the IH power ratio. For example, when the heating coil 20 is manufactured by winding a copper wire having a diameter of about 1 mm for 25 turns, the IH power ratio of the heating coil 20 is 71.9% in the first embodiment, but the second embodiment Then, it can be improved to 98%.

  The heating coil 20 according to the second embodiment may have an arbitrary planar shape such as a circle in the YZ plane, but the entire surface of the metal plate 30 generates heat, and the metal plate 30 and the air In order to maximize the contact area, it is preferable to have the same planar shape as the metal plate 30.

  Further, in the heating coil 20 according to the second embodiment, the conductive wire 42 is wound once in FIGS. 8 and 9, but may be wound twice as shown in FIGS. 10 and 11.

Embodiment 3 FIG.
A third embodiment of the hand dryer according to the present invention will be described with reference to FIGS. Since the hand dryer 1 of Embodiment 3 is the same as that of Embodiment 2 except the structure of each heater cell 14, description is abbreviate | omitted about the overlapping content.

  FIG. 12 is a cross-sectional view of the IH heater 4 according to the third embodiment, and FIG. 13 is an exploded view of each heater cell 14 and is the same as FIGS. 8 and 9 respectively. Unlike the second embodiment, the heater cell 14 of the third embodiment is configured by providing a support column 44 between a pair of metal plates 30 and winding a conductive wire 42 coated with an insulating film around it. The

  The struts 44 employed in the heater cell 14 of the third embodiment may be formed integrally with the pair of metal plates 30 using the same material, or after being formed using a material different from the metal plate 30, You may connect to the metal plate 30 using arbitrary connection means, such as welding, screwing, or an adhesive agent. As described above, the heater cell 14 according to the third embodiment has a form like a bobbin used in a sewing machine.

  When the support 44 is made of a magnetic metal, the support 44 itself generates heat upon receiving the AC magnetic field of the heating coil 20, but the heat transfer efficiency of the support 44 is not directly in contact with the air flowing through the flow path 40. Is inferior to the metal plate 30. Therefore, in order for the metal plate 30 to generate heat more preferentially by receiving the alternating magnetic field of the heating coil 20, the support column 44 is preferably made of a nonmagnetic material such as copper, aluminum, resin, or ceramic.

  In addition, the heating coil 20 of the third embodiment may have an arbitrary planar shape such as a circle in the YZ plane as in the second embodiment, but the entire surface of the metal plate 30 generates heat, In order to maximize the contact area between the metal plate 30 and air, the metal plate 30 is preferably formed to have the same planar shape as the metal plate 30. Therefore, the support 44 is formed to have the same planar shape as that of the metal plate 30 so that the planar shape of the conductive wire 42 wound around the support 44 has the same (similar) shape as that of the metal plate 30. The

  By the way, in the said embodiment, the outer frame 10 can be formed using arbitrary materials, and a space | interval and space | interval between the side edge parts 37 (both ends of a Y direction, refer FIG. 12) of the metal plate 30 are possible. A spacer may be provided, but when the outer frame 10 is formed of a non-magnetic material or is substantially separated from the metal plate 30, the magnetic flux (magnetic field) generated by the heating coil 20 is non-magnetic. The body cannot pass through the outer frame 10 or the space, and a leakage magnetic flux is generated. At this time, the efficiency with which the metal plate 30 generates heat by the alternating magnetic field generated by the heating coil 20 is reduced by the leakage magnetic flux. Therefore, the heater cell 14 includes a metal tube (a body to be heated) 38 made of a magnetic material and integrally formed in a cylindrical shape so as to surround the heating coil 20 as shown in FIG. 14 instead of the pair of metal plates 30. You may do it. Thereby, the leakage magnetic flux in XY plane can be suppressed and more efficient heat_generation | fever of the to-be-heated body 38 can be assisted. Instead of the integrally formed hollow rectangular parallelepiped body to be heated 38, a separate side wall (not shown) for connecting the side end portions 37 of the pair of metal plates 30 is provided, and leakage magnetic flux is provided. It may be suppressed.

Embodiment 4 FIG.
Embodiment 4 of the hand dryer according to the present invention will be described with reference to FIGS. Since the hand dryer 1 of Embodiment 4 is the same as that of Embodiment 1 except the structure of the IH heater 4, description is abbreviate | omitted about the overlapping content.

  FIG. 15 is a cross-sectional view taken along the XY plane of the IH heater 4 according to the fourth embodiment, and FIG. 16 is an exploded view showing a part of the IH heater 4. The IH heater 4 shown in FIGS. 15 and 16 generally includes a plurality (five in FIG. 15) of hollow metal tubes (heated bodies) 50 each having a flow path 40 extending through in the Z direction, and YZ. And a plurality (four in FIG. 15) of heating coils 20 arranged substantially parallel to the plane. Each heating coil 20 is electrically connected in series and is driven by the control circuit 5. The number of heating coils 20 is not limited to four, and an arbitrary number of heating coils 20 may be connected in series. Further, as shown in the first and second embodiments, a plurality of heating coils 20 are connected in parallel, a group of a plurality of heating coils 20 connected in parallel is connected in series, or parallel connection and series connection are arbitrary. You may connect in combination. At this time, the directions of the magnetic fields generated by the plurality of heating coils 20 are preferably the same. Each metal tube 50 has a flat surface 52 substantially parallel to the YZ plane, and the flat surface 52 of the adjacent metal tube 50 is formed by a column 44 similar to that of the third embodiment provided therebetween. It is connected. That is, the heating coil 20 of the fourth embodiment is formed by winding the conductive wire 42 with an insulating coating around the support pole 44 as in the third embodiment.

  Unlike the first embodiment, the IH heater 4 according to the fourth embodiment has a flow path 40 formed in the hollow space of the metal tube 50, and the outer frame 10 is not necessarily required and can be omitted. Can be manufactured at a low cost with a simpler configuration. The IH heater 4 according to the first to third embodiments is manufactured by incorporating a plurality of individually manufactured heater cells 14 into the outer frame 10, whereas the IH heater 4 according to the fourth embodiment Since it is manufactured by winding the conductive wire 42 with insulating coating around the pillars 44 of the plurality of connected metal tubes 50, the manufacturing is easy and the manufacturing cost can be further reduced.

  In the IH heater 4 thus configured, when a high frequency current is supplied to the heating coil 20, magnetic lines of force are generated, and the eddy current induced thereby is formed in the metal tube 50 to generate heat. Since the heated metal tube 50 is in direct contact with the air flowing through the flow path 40, the air can be heated extremely efficiently and with high responsiveness.

  Further, the IH heater 4 of the fourth embodiment may have a through fixture 54 that extends in the X direction and penetrates the plurality of metal tubes 50 and the columns 44 as shown in FIG. The penetration fixture 54 is configured using a fixing means (bolt, nut) 55 such as a general screw, and is fixed to a series of metal tubes 50. Thus, the IH heater 4 can be mechanically reinforced and the assembly workability at the time of manufacture can be improved.

  Furthermore, although the heated object of the IH heater 4 of Embodiment 4 was demonstrated as the metal pipe 50, as shown in FIG. 18, even if it uses the same pair of metal plates 30 as Embodiments 1-3. Good. At this time, a spacer 56 may be separately provided around the penetration fixture 54 in the flow path 40 through which air flows. If necessary, the spacer 56 can be formed of a nonmagnetic material, and the metal plate 30 can be preferentially heated by the penetration fixture 54 by the AC magnetic field of the heating coil 20.

Embodiment 5 FIG.
Embodiment 5 of the hand dryer according to the present invention will be described with reference to FIGS. Since the hand dryer 1 of Embodiment 5 is the same as that of Embodiment 4 except the structure of the IH heater 4, description is abbreviate | omitted about the overlapping content.

  FIG. 19 is a perspective view of the IH heater 4 according to the fifth embodiment. The IH heater 4 in FIG. 19 has a plurality (three in FIG. 19) of heater cells 14, and each heater cell 14 has a hollow metal tube (heated object) 50 having a flow path 40 extending through in the Z direction. And a heating coil 20 around which an electrically conductive wire 42 with an insulating coating is wound around its outer surface 58. The conductive lines 42 of the heater cells 14 are connected in series and driven by a current supply circuit (not shown in FIG. 19). Note that the number of heater cells 14 is not limited to three, and an arbitrary number of heater cells 14 may be connected in series. A plurality of heater cells 14 may be connected in parallel, or may be connected in any combination of parallel connection and series connection. Each metal tube 50 has a rectangular parallelepiped shape in FIG. 19, but may have an arbitrary hollow shape such as a cylindrical shape. In the electrothermal converter 1 of the fifth embodiment, the flow path 40 is formed in the hollow space of the metal tube 50 as in the fourth embodiment, and the outer frame 10 is not necessarily required and can be omitted.

  According to the IH heater 4 of the fifth embodiment configured in this way, as with the previous embodiments, when a high frequency current is supplied to the heating coil 20, magnetic field lines are generated, and the metal tube 50 is induced thereby. An eddy current is formed and heat is generated. Since the heated metal tube 50 is in direct contact with the air flowing through the flow path 40, the air in the flow path 40 can be heated very efficiently and with good responsiveness.

  Since the heating coil 20 of the IH heater 4 shown in FIG. 19 is formed by winding the conductive wire 42 clockwise as viewed from above, a current flows in the direction indicated by the arrow in the figure. Each heater cell 14 has a magnetic pole with the N pole on the bottom and the S pole on the top. However, in order to avoid the magnetic fluxes of the adjacent heater cells 14 from interfering with each other, it is preferable to make the magnetic poles of the adjacent heater cells 14 different from each other. In order to realize this, as shown in FIG. 20, among the three continuous heater cells 14, the conductive wire 42 of the central heater cell 14 is wound in the counterclockwise direction along the outer surface 58 of the metal tube 50. The That is, the heater cell 14 disposed in the center is configured such that the N pole is formed upward, and the other adjacent heater cells 14 are formed such that the S pole is formed upward. In this way, it is possible to provide the IH heater 4 capable of efficiently converting electromagnetic field energy into heat energy without interfering with the magnetic fluxes of adjacent heater cells 14.

  Moreover, although the heating coil 20 of Embodiment 5 heats the metal tube 50 disposed on the inner side, the AC magnetic field generated by the heating coil 20 is naturally formed also on the outer side of the heating coil 20. The Therefore, as shown in FIGS. 21 and 22, another metal tube (hollow conductor) 60 is disposed outside the heating coil 20, so that the AC magnetic field energy formed outside the heating coil 20 can be efficiently reduced. It is preferable to convert it into thermal energy. The outer metal tube, that is, the hollow conductor 60 is preferably made of the same metal material as the metal tube 50 provided inside the heating coil 20. At this time, the inner flow path 40 formed inside the inner metal tube 50 and the outer flow path 41 formed outside the hollow conductor 60 and inside the frame 10 in FIG. 21 are formed. . The air flowing through the inner channel 40 and the outer channel 41 merges and is guided into the duct 8 of the hand dryer 1. In this way, it is possible to realize the IH heater 4 that can convert the alternating magnetic field generated by the heating coil 20 into heat energy very efficiently.

  In the embodiment described so far, the surfaces (the flat surfaces of the pair of metal plates 30, the inner surfaces of the metal tubes 50, and the outer surfaces of the hollow conductors 60) forming the flow path 40 are air pressure loss. However, it is preferable to have a form in which the surface area is enlarged in order to further improve the heat dissipation effect. That is, as shown in FIGS. 23A and 23B, the surface forming the flow path 40 has irregularities in a cross section in a direction substantially perpendicular to the flow path 40 (that is, the YZ plane). It is preferable that it is comprised so that it may have.

Embodiment 6 FIG.
Embodiment 6 of the hand dryer according to the present invention will be described with reference to FIGS. The hand dryer 1 of the sixth embodiment has the same configuration as that of the first embodiment except that the IH heater 4 is disposed at two locations in the duct 8 between the blower 3 and the injection nozzle 7. Therefore, the description of the overlapping contents is omitted.

  As described above, the IH heater 4 according to the sixth embodiment is disposed at two locations in the duct 8 between the blower 3 and the injection nozzle 7 as shown in FIG. 7 is arranged adjacent to. However, when the IH heater 4 is disposed between the blower 3 and the injection nozzle 7, the effect of the present invention according to the sixth embodiment can be obtained even when only one is provided.

  According to the hand dryer 1 of the first embodiment shown in FIG. 24, the IH heater 4 is disposed between the air inlet 6 and the blower 3, so that the air warmed by the IH heater 4 is sent to the duct 8. While passing through the inside, the duct 8 is deprived of heat, and when it is ejected from the ejection nozzle 7, a sufficiently high temperature may not be maintained. Therefore, in order to ensure the temperature of the jet airflow ejected from the ejection nozzle 7, the temperature of the metal plate 30 is maintained at a substantially high temperature (for example, 120 ° C.) during the standby of the hand dryer 1, and the duct 8. And it was necessary to preheat the air in the flow path 40.

  According to the IH heaters 4 of the first to fifth embodiments described so far, the heated objects such as the metal plate 30 and the metal tube 50 are in direct contact with the air flowing through the flow path 40, so that the air is extremely efficient. And with good responsiveness. Therefore, it is not necessary to preheat the air in the flow path 40, and the air can be instantaneously heated to a temperature at which it can be used immediately. Then, by disposing the IH heater 4 adjacent to the blower 3, it is possible to prevent the duct 8 from taking heat away. Thus, since it is not necessary to preheat the air during standby, power consumption during standby can be minimized.

  Even if the air must be preheated during standby, the power consumption during standby can be substantially reduced by reducing the preheating time. In Embodiment 1, it is detected whether a user's hand was inserted in the hand insertion space 9 using the hand sensor attached to the hand dryer 1, and the hand dryer 1 operate | moves according to this. So that it is controlled. In the hand dryer 1 of the sixth embodiment, in addition to this hand sensor, the user uses a human sensor (not shown) installed in the room in the bathroom where the hand dryer 1 is installed. It may be controlled to detect that it has entered the bathroom and start preheating the air in the flow path 40 in response to this. In addition to human sensors, it responds to signals from photo sensors that detect that the lighting in the bathroom is lit, sensors that work with the lighting switch, and sensors that detect that water has been used in the bathroom. And you may comprise the hand-drying apparatus 1 so that the air in the flow path 40 may begin to preheat.

  FIG. 25 is an enlarged view of a part of the housing 2 including the ejection nozzle 7 of the hand dryer 1. 25 corresponds to the IH heater 4 viewed from the Z direction in FIG. 19 or 20. In FIG. 19, the air is directly ejected from the flow path 40 of each heater cell 14 of the IH heater 4, that is, each opening of each heater cell 14 functions as the ejection nozzle 7. According to the hand dryer 1 configured as described above, it is possible to prevent the duct 8 from taking heat away from the air heated by the IH heater 4.

  When the IH heater 4 is generated adjacent to the ejection nozzle 7 or when the opening of each heater cell 14 functions as the ejection nozzle 7, the alternating current magnetic field from the heating coil 20 is applied to a wristwatch worn by the user. 25, a magnetic shield plate 64 using a magnetic material such as ferrite is disposed around the IH heater 4 to shield the AC magnetic field from the heating coil 20 as shown in FIG. It is preferable to do.

  An experiment was conducted to compare the performance of the hand dryer 1 using the IH heater of the present invention and the conventional hand dryer using a sheathed heater.

  The IH heater 4 used here is the same as that shown in FIG. 2, but four sets of heater cells 14 connected in parallel are connected in series, and each heater cell 14 is heated. The coil 20 has a copper thin film 24 patterned in a spiral pattern on both surfaces of a substrate 23 (see FIG. 5). Each of the heating coils 20 had 25 turns and the thickness of the copper thin film 24 was 35 μm. At this time, the resistance value of the heating coil 20 was 1.19Ω when measured at a frequency of 20 kHz using an impedance analyzer. The metal plate 30 was formed into a size of 60 mm × 60 mm × 1 mm using two types of stainless steel, SUS430 (JIS standard) which is magnetic stainless steel and SUS304 (JIS standard) which is nonmagnetic stainless steel (see FIG. 3). . The resistance values of the heater cell 14 in which the heating coil 20 was sandwiched between a pair of SUS430 stainless steel plates and SUS304 stainless steel plates were similarly measured at a frequency of 20 kHz, and were 4.24Ω and 2.20Ω, respectively. Since these resistance values are the total value of the resistance value of the heating coil 20 and the resistance value of the metal plate (stainless steel plate) 30, when the resistance value of the heating coil 20 is subtracted from the total resistance value, the SUS430 stainless steel plate and The resistance values of the SUS304 stainless steel plate are 3.05Ω and 1.01Ω, respectively (note that the electrical resistivity of the SUS430 stainless steel plate and the SUS304 stainless steel plate is 60 μΩcm and 72 μΩcm, respectively).

In general, electric power (electric energy) supplied to the heating coil is consumed by the heating coil 20 and each stainless steel plate 30 and converted into thermal energy. However, Joule heat (Hc) generated from the heating coil 20 and the stainless steel plate 30 are converted into heat energy. Is defined as IH power ratio {Hm / (Hc + Hm)}. At this time, the IH power ratio may be considered to be equal to the ratio of the resistance value of the stainless steel plate to the total value of the resistance value of the heating coil and the resistance value of the stainless steel plate. The ratio of the thermal energy (W ₄₃₀ , W ₃₀₄ ) converted by the SUS430 stainless steel plate and the SUS304 stainless steel plate to the entire supplied power (Wt), that is, the IH power ratio is the resistance value of the heating coil and the resistance value of the stainless steel plate. The ratio of the resistance value of the stainless steel plate to the total value is 71.9% (W ₄₃₀ / Wt) and 45.9% (W ₃₀₄ / Wt), respectively. Therefore, as the IH power ratio is larger, the electric-thermal energy conversion efficiency can be increased. Therefore, the metal plate 30 is preferably formed using magnetic stainless steel SUS430 rather than nonmagnetic stainless steel SUS304. In other words, by suppressing the resistance value of the heating coil 20 as much as possible as compared with the resistance value of the stainless steel plate, the electric-thermal energy conversion efficiency of each heater cell 14 can be remarkably improved.

  For example, in the hand dryer that employs the conventional sheathed heater described in Patent Document 1, the waiting sheathed heater is 1100 W so that the temperature of the heat storage and radiation fins disposed adjacently is maintained at 200 ° C. The power is intermittently supplied. In order to supply power continuously and maintain the temperature of the sheathed heater at 200 ° C., 120 W of electric power was required.

  Then, after the temperature of the sheathed heater was stabilized at 200 ° C. (pre-heat treatment), an operation test was repeated in which the operation for 10 seconds and the standby for 10 seconds were repeated. During operation, 370 W of power was supplied to the sheathed heater and 730 W of power was supplied to the blower to form a jet stream. During standby, the blower 3 was stopped and 1100 W of power was supplied to the sheathed heater. At this time, in a conventional hand drying apparatus using a sheathed heater, the temperature of the sheathed heater, the temperature of the jet air current (ejection temperature) and the temperature of the outside air to be sucked (intake air temperature) are measured, The graph of FIG. 26 was obtained. Similarly, in this conventional hand dryer, after the temperature of the sheathed heater is stabilized at 200 ° C., the intake air temperature and the ejection temperature that fluctuate in 10 seconds during operation at the first operation, the fifth operation, and the 60th operation. The difference (temperature rise) was measured and the graph of FIG. 27 was obtained.

  On the other hand, in the hand dryer 1 using the IH heater of the present invention, the standby IH heater is supplied with a high-frequency current so that the temperature of the stainless steel plate 30 is maintained at 120 ° C. for preheating, and SUS430 stainless steel. The IH heater using a plate required 48 W, and the IH heater using a SUS304 stainless steel plate required 60 W. Note that the power loss due to the circuit supplying the high-frequency current is not included in these. As a comparative example, when a direct current was supplied to an IH heater using a SUS430 stainless steel plate and the temperature of the stainless steel plate was maintained at 120 ° C., 82 W of power was required.

  These hand dryers 1 were subjected to an operation test in which 10 seconds of operation and 10 seconds of standby were repeated as described for the hand dryer using a conventional sheathed heater. That is, high-frequency power of 304 W and 945 W was supplied to the IH heaters in operation and standby, respectively, by subtracting power loss due to the current supply circuit.

  Thus, when a high frequency current is supplied to the IH heater 4 using the SUS430 stainless steel plate 30, the temperature of the heater cell 14 (IH heater temperature (center)) arranged in the center of the IH heater 4 (the tenth from one end), The temperature (IH heater temperature (end)) of the heater cell 14 arranged at the end of the IH heater 4 (first from one end), the temperature of the jet air flow (ejection temperature), and the temperature of the outside air to be sucked (intake air temperature) The graph of FIG. 28 showing the change over time of) was obtained. In addition, in the hand dryer that supplies high-frequency current to the IH heater 4 using the SUS430 stainless steel plate 30, the intake air temperature and the ejection temperature during the first operation, the fifth operation, and the 60th operation after the pre-heat treatment as in FIG. FIG. 29 showing how the difference (temperature rise) changes in 10 seconds during operation was obtained.

  Moreover, regarding the hand dryer which supplied the high frequency current to the IH heater 4 using the SUS304 stainless steel plate 30, FIG. 30 and FIG. 31 which are the same graphs as FIG. 28 and FIG. 29 were obtained. Furthermore, when a direct current was supplied to the IH heater 4 using the SUS430 stainless steel plate 30, the graphs of FIGS. 32 and 33 were obtained.

  Referring to FIGS. 26 to 33, a hand dryer using a conventional sheath heater, a hand dryer using an IH heater 4 according to the present invention supplied with a high frequency power source using a SUS430 stainless steel plate and a SUS304 stainless steel plate. The device 1 and the hand dryer using the IH heater 4 supplied with DC power using the SUS430 stainless steel plate 30 will be compared.

  During the first operation after the pre-heat treatment, the difference between the intake air temperature and the ejection temperature (temperature increase) was the smallest in the conventional hand dryer, reaching 15 K after 3 seconds of operation and 19 K after 10 seconds ( FIG. 27). On the other hand, according to the hand drying apparatus 1 employing the IH heater 4 according to the present invention, the difference between the intake air temperature and the ejection temperature (temperature rise) reaches 30K after 1 to 2 seconds after the operation, and then drops slightly. After 2 seconds, it became 27-28K. Thus, the temperature rise by the conventional hand dryer at the first operation after the pre-heat treatment is smaller than that of the hand dryer 1 according to the present invention. This is because the efficiency of heat transfer from the sheathed heater to the air via the heat storage and radiating fins is not sufficient, and the temperature of the sheathed heater during standby needs to be kept very high (200 ° C.). The hand dryer comprises a hand dryer main body and a separate heating device including a sheathed heater. During standby, the lid provided between the hand dryer main body and the heater closes and the sheathed heater heats up. This is because the air in the main body of the hand dryer is not warmed in order to protect the main body of the hand dryer. On the other hand, according to the hand dryer 1 employing the IH heater 4 according to the present invention, the stainless steel plate 30 heated by the eddy current is in direct contact with the air flowing through the flow path 40, so that the air is Heating can be performed very efficiently and with high responsiveness. Thereby, the IH heater 4 according to the present invention can set the preheating temperature lower (for example, 120 ° C.) than the conventional hand dryer, and can substantially reduce energy consumption.

  Next, the difference (temperature rise) between the intake air temperature and the ejection temperature at the fifth and 60th operation after the preheat treatment is compared. The temperature rise at the time of the fifth operation is about 22 to 24 K in the conventional hand dryer using the sheathed heater, and about each in the hand dryer 1 using the SUS430 stainless steel plate and the SUS304 stainless steel plate supplied with the high frequency current. 27 to 28K and about 26 to 27K, and about 24K in the hand dryer supplied with DC power using a SUS430 stainless steel plate.

  Similarly, the temperature rise during the 60th operation after the pre-heat treatment is about 23K in the conventional hand drying device using the sheathed heater, and the hand drying device using the SUS430 stainless steel plate and the SUS304 stainless steel plate supplied with high frequency power. 1 was about 24K and about 22K, respectively, and about 17-18K in the hand dryer supplied with DC power using a US430 stainless steel plate.

  As described above, the IH heater 4 of the present invention, especially the IH heater 4 using SUS430, is equivalent to or more than the sheathed heater in spite of supplying less power than the power supplied to the conventional sheathed heater. An increase in temperature was obtained. In other words, the hand dryer employing the IH heater 4 according to the present invention has higher heat conversion efficiency than the conventional product. However, when a direct current was supplied to the IH heater 4 using SUS430, the temperature rise during the 60th operation after the pre-heat treatment was about 17 to 18 K, which was inferior to the conventional hand dryer.

  As described above, the ratio of the Joule heat (Hm) generated in the stainless steel plate 30 to the Joule heat (Hc) generated from the heating coil 20 is defined as the IH power ratio (Hm / Hc). The graph of FIG. 34 which shows a relationship with the difference (temperature rise) of the ejection temperature was obtained. Specifically, since the IH power ratio is proportional to the resistance ratio (Rm / Rc) of the resistance value (Rc) of the heating coil 20 and the resistance value (Rm) of the stainless steel plate 30, the SUS430 stainless steel plate and the SUS304 stainless steel plate. The temperature at the first, fifth and 60th operation after the pre-heat treatment in the point corresponding to the case of using (11.9% and 45.9% respectively) and the case of supplying DC power (0%) The rise was plotted. As can be seen from FIG. 34, the temperature rise during the first, fifth and 60th operations after the pre-heat treatment, that is, the temperature of the jet airflow increases in proportion to the IH power ratio.

  Since the air in the hand dryer 1 is warmed by the preheating, the temperature rise during the first operation after the preheat treatment does not increase significantly even if the IH power ratio increases. However, as the number of operations increases, the effect of preheating is diluted, and the temperature rise is highly dependent on the IH power ratio. That is, since the power supplied to the IH heater 4 is constant regardless of the IH power ratio, the amount of heat generated by the entire IH heater 4 is the same, but as shown in FIG. 34, the IH power ratio is large. The temperature (temperature rise) of the jet stream that is ejected increases. Therefore, the IH heater 4 according to the present invention is preferably as the IH power ratio is larger in the context of heating more efficiently.

  FIG. 35 is a graph plotting the average temperature of the surface of the stainless steel plate 30 of the IH heater 4 when the operation (10 seconds) and the stop (10 seconds) are repeated 60 times after the pre-heat treatment. As can be seen from FIG. 35, the average temperature of the SUS430 stainless steel plate with the high IH power ratio supplied with the high frequency current (71.9%) is the highest, and then the SUS304 stainless steel plate (45 0.9%) was high, and the average temperature of the SUS430 stainless steel plate (0%) supplied with DC power was low. From this result, the IH heater 4 according to the present invention is preferably as the IH power ratio is larger from the viewpoint of keeping the surface temperature of the stainless steel plate 30 high.

  In order to increase the IH power ratio, the resistance of the heating coil 20 only needs to be reduced. To that end, the thickness of the metal thin film 23 is increased to increase the cross-sectional area, and the number of turns of the heating coil 20 is increased. The total wiring length may be shortened, or the metal thin film 23 may be formed using a material having a small specific resistance. Moreover, the IH power ratio can be increased by forming the stainless steel plate 30 using a metal material having a higher magnetic permeability or a larger volume resistivity.

  In the IH heater 4 using the above-described SUS430 stainless steel plate and SUS304 stainless steel plate, the reserve power necessary to maintain these stainless steel plates 30 at 120 ° C. during the preheating is 48 W and 60 W, respectively, and a DC power supply is supplied. The reserve power of the IH heater 4 using the SUS430 stainless steel plate was 82W. FIG. 36 is a graph showing the relationship between these IH power ratios and standby power. As apparent from FIG. 36, the reserve power of the IH heater 4 is linearly reduced with respect to the IH power ratio. That is, the IH heater 4 according to the present invention is preferably as the IH power ratio is large in that the reserve power necessary for preheating the stainless steel plate 30 to a predetermined temperature is reduced and the energy consumption is reduced.

  In the above description, the stainless steel plate 30 of the IH heater 4 described above has a thickness of 0.6 mm or 1 mm and is configured to store heat by being heated by the heating coil 20 during standby, but is thicker. When formed, the heat storage effect is increased, and the power supplied to the heating coil 20 during operation can be reduced. On the other hand, when the power supply capacity of the hand dryer is not limited and the power that can be supplied to the heating coil 20 during operation can be sufficiently increased, the stainless plate 30 is made thinner and pre-heating is not performed. The surface temperature of the plate 30 can be increased more quickly. However, the eddy current induced in the stainless steel plate 30 is “penetration depth (δ = 5030 × √ (ρ / μf); ρ is resistivity, μ is relative permeability, and f is current frequency)” near the surface. If the stainless steel plate 30 is made thinner than the penetration depth, a leakage magnetic flux is generated and the heat generation efficiency is lowered. Therefore, it is preferable to make the stainless steel plate 30 thicker than the penetration depth even when the power that can be supplied to the heating coil 20 during operation can be sufficiently increased without performing preheating. Based on the above equation, the penetration depth (δ) decreases as the frequency of the high-frequency current increases, the resistivity of the stainless steel plate 30 decreases, or the relative magnetic permeability of the stainless steel plate 30 increases. Therefore, by using a high-frequency power source having a high frequency, or using a stainless plate 30 having a high resistivity or a low relative permeability, the penetration depth is reduced and the stainless plate 30 is thinned to perform preheating. Without this, the surface temperature of the stainless steel plate 30 can be raised more quickly.

  In the above embodiments and examples, the manual drying device provided with the IH heater according to the present invention has been described so far, but this IH heater can also be used as other hot air generating devices such as a heating device and a drying device. It can be used similarly. The present invention should not be construed as being limited to the embodiments and examples, but is defined by the appended claims, and variations and modifications apparent to those skilled in the art can be made within the spirit and scope of the present invention. It should be understood that it is included in the present invention without departing from the invention.

  The present invention relates to a hot air generator and a hand dryer using the same, and more particularly to a hot air generator employing a heating method using electromagnetic induction and a hand dryer using the same.

  Hand dryers are widely used in toilets used by many people such as public facilities and offices as a device for hygienically drying hands after washing. The hand dryer uses a warm air type that blows warm air with a low wind speed from a wide outlet and evaporates water droplets attached to the hand after washing, and a high air flow (jet stream) from a small nozzle. There is a jet type that blows off water droplets that erupt and adhere to the hand. Furthermore, some jet-type hand dryers reduce the time to dry the hands and remove the air squirting using a heater in order to eliminate the user's discomfort caused by exposure to a cold jet stream. Those that are preheated are commercially available. Thus, a heater for heating air is widely used in both hot air type and jet type hand dryers.

  For example, a conventional hand dryer disclosed in Patent Document 1 generally has a heating device having an intake port and an air supply port, and a suction port connected to the air supply port of the heating device. Air is sucked from the intake port of the heating device and heated by the heating device by the high-pressure airflow generator disposed in the hand drying device body, and the hand drying device body Inhaled (see especially FIG. 1).

  In the hand-drying device of Patent Document 1, the heating device includes a sheathed heater and a heat storage and radiation fin made of aluminum metal having a large specific heat that is in close contact with the sheathed heater. The sheathed heater generates heat when power is supplied while the user is not using the hand dryer, that is, while the high pressure airflow generator is not operating. The heat from the sheathed heater is stored in the heat storage and radiation fins, and the air heated through the heat storage and radiation fins is stored in the heating device. When the user uses the hand dryer, the power supply to the sheathed heater is stopped and the high-pressure airflow generator is activated, so that the heated air stored in the heater is stored in the hand dryer main body. While being sucked in, the air sucked from the intake port of the heating device is sequentially heated through the heat storage and radiation fins and is similarly supplied into the main body of the hand dryer.

  Moreover, in the hand dryer of patent document 2, the PTC (Positive Temperature Coefficient) heater which has another heating mechanism is provided between the high-speed blower and blowing nozzle as a ventilation means. When the sensor detects that the user's hand has been inserted into the processing space of the hand dryer, the high speed blower and the PTC heater are supplied with power, and the air sucked from the suction port of the hand dryer is supplied with the high speed blower and Heated via the PTC heater, warm air is blown from the ejection nozzle. When the user retracts his / her hand from the processing space, the high speed blower and the PTC heater are stopped.

  Furthermore, the hand drying device described in Patent Document 3 includes a flat heater disposed in the vicinity of the air intake, and the flat heater includes ceramics or metal having a thermal conductivity of 50 W / m · K or more. And a resistance heating element having a thickness of 5 mm or less provided thereon. When the sensor detects that the user's hand has been inserted into the hand insertion section of the hand dryer, the flat heater and the blower, which is a high-pressure air flow generator, are activated, and the air flow flowing in from the air intake is flat. It is heated by the heater.

  Further, according to Patent Document 4, a hand washing and drying apparatus is disclosed in which a warm washing mist is ejected from a duct to wash a hand, and then a hand is dried by supplying a high-speed air flow. In this manual washing and drying apparatus, it is taught that a high-frequency induction heater, an electric heater, a ceramic heater, or a gas heater can be adopted as a heating means for heating the cleaning mist. Further, it is described that another high-frequency induction heater, an electric heater, a ceramic heater, or a gas heater can be used as means for heating the high-speed air flow to a predetermined temperature of, for example, 50 to 80 ° C. However, Patent Document 4 does not describe or suggest any specific configuration of these heating means.

JP-A-10-75915 JP 2006-187435 A JP 2005-34272 A JP 2000-60763 A

  In the hand dryer described in Patent Document 1, as described above, the heat from the sheathed heater supplied during standby when the high-pressure airflow generator is not operating is stored in the heat storage and radiation fins, and the heat storage and radiation fins. The air heated via is stored in the heating device. That is, when the high-pressure airflow generator is operating, power supply to the sheathed heater is stopped. Therefore, since the power required to drive the high-pressure airflow generator and the power required to heat the sheathed heater are not supplied at the same time, there is no need to increase the power supply capacity of the hand dryer, Since it is necessary to continuously supply power to the sheathed heater of the heating device even during standby, there is a problem that power consumption during standby cannot be suppressed.

  In addition, since the heated air is already stored in the heating device before the hand drying device is used, warm air is blown out as soon as the hand drying device is used, which is extremely comfortable for the user. It is. However, when this hand dryer is used very frequently, the time of the operation state becomes longer than the standby state of the hand dryer, it becomes impossible to accumulate a sufficient amount of heat in the standby state, and the temperature of the jet airflow decreases. There was a problem.

  Furthermore, a sheathed heater generally has a heat generating conductor coated with an insulator, and since air is heated through an insulator heated by the heat generating conductor, the thermal resistance from the heat generating conductor to the air is large. That is, it is inferior to thermal conductivity. Therefore, it is necessary for a hand dryer using a sheathed heater to accumulate sufficient heat in a large volume of heated air or heat storage and radiation fins, and to protect the components of the hand dryer main body from a high temperature heating device. For this reason, it is necessary to provide a heating device that is separate from the main body of the hand dryer, which is a factor that hinders downsizing of the hand dryer.

  According to the hand dryer disclosed in Patent Document 2, when a user inserts a hand into the processing space of the hand dryer, power is supplied to both the high-pressure airflow generator and the PTC heater, and the PTC heater is in standby mode. Therefore, there is an advantage that the power consumed by the PTC heater during standby can be reduced. However, since the resistance value of the PTC heater changes depending on the temperature, the resistance value of the PTC heater increases especially when exposed to the wind of a high-speed blower, and sufficient power is not supplied to the PTC heater, and it is continuously used. As it was, the temperature of the warm air tended to decrease.

  Further, as described above, the hand dryer described in Patent Document 3 has a resistance heating element provided on a ceramic or metal substrate having high thermal conductivity, and the temperature of the air flow is similar to that of a PTC heater. Even if power is supplied to the heater at the same time as the operation of the blower, which is a high-pressure airflow generator, without change, the heater is heated in 1 to 2 seconds, and warm air at 70 ° C is stabilized within 2 to 3 seconds. Can be supplied. However, for this purpose, it is necessary to sufficiently increase the surface area of the flat heater, but there is a problem that the production cost is high because the structure of the flat heater is complicated.

  Patent Document 4 suggests a hand washing and drying apparatus using a high-frequency induction heater, an electric heater, a ceramic heater, or a gas heater as a means for heating a cleaning mist or a high-speed air stream. It does not describe or suggest any specific structure and usage of the heating means.

A hot air generator according to one aspect of the present invention includes an induction coil made of a conductive material, a heater configured by at least one heated body disposed adjacent to the induction coil , and the heated body. A power source that supplies a high-frequency current to the induction coil, an outer frame that forms at least one flow path between the object to be heated, and a blower that forms an air flow in the flow path. And the air in the flow path is heated by the heated body.

  According to the hot air generator according to one aspect of the present invention, by supplying a high-frequency current, a heated body disposed adjacent to the induction coil is heated, and the heated body flows through the flow path. Since it is in direct contact with the air, it is possible to heat the air very efficiently and responsively.

It is a side view which shows the hand-drying apparatus by Embodiment 1 which concerns on this invention. FIG. 3 is a perspective view showing a specific structure of the IH heater according to the first embodiment. It is the expansion perspective view which expanded a part shown with the broken line of FIG. FIG. 3 is a circuit wiring diagram of the IH heater according to the first embodiment. (A) is a perspective view which shows the specific structure of the heating coil of Embodiment 1, (b) is the front view, (c) is sectional drawing seen from the VC-VC line of FIG.5 (b). . It is a drive circuit diagram for supplying a high frequency current to a heating coil. It is a wave form diagram which shows the alternating current supplied to a heating coil. It is sectional drawing cut | disconnected by the XY plane of the IH heater of Embodiment 2. FIG. It is an exploded view of one heater cell of the IH heater shown in FIG. It is sectional drawing similar to FIG. 8, Comprising: The conductive wire is wound twice. It is the same exploded view as FIG. 9, Comprising: The conductive wire is wound twice. FIG. 6 is a cross-sectional view of the IH heater according to Embodiment 3 cut along the XY plane. FIG. 13 is an exploded view of one heater cell of the IH heater shown in FIG. 12. FIG. 10 is a cross-sectional view of an IH heater according to a modification of the third embodiment. It is sectional drawing cut | disconnected by the XY plane of the IH heater of Embodiment 4. FIG. FIG. 16 is an exploded view showing a part of the IH heater shown in FIG. 15. FIG. 10 is a cross-sectional view of an IH heater according to a modification of the fourth embodiment. FIG. 10 is a cross-sectional view of an IH heater according to another modification of the fourth embodiment. FIG. 10 is a perspective view of an IH heater according to a fifth embodiment. FIG. 10 is a perspective view of an IH heater according to a modification of the fifth embodiment. FIG. 10 is a cross-sectional view taken along the XY plane of an IH heater according to another modification of the fifth embodiment. It is a partially broken perspective view of the IH heater shown in FIG. It is sectional drawing cut | disconnected by the XY plane of the metal plate and metal tube by the modification of Embodiment 1-5. It is a side view which shows the hand-drying apparatus by Embodiment 6. FIG. 25 is a partially enlarged view of the housing including the ejection nozzle shown in FIG. 24. It is a graph which shows the time-dependent change of the temperature of a sheathed heater, the temperature of the jet air current to be ejected (ejection temperature), and the temperature of the outside air to be inhaled (intake air temperature) regarding a conventional hand dryer using a sheathed heater. Regarding the conventional hand dryer using a sheathed heater, the difference between the intake air temperature and the jet temperature (temperature rise) changes during the 10 seconds of operation after the first heat treatment and during the first, fifth and 60th operation. It is a graph which shows a mode. It is the same graph as FIG. 26 at the time of supplying a high frequency current regarding the hand dryer of this invention which employ | adopted the IH heater using a SUS430 stainless steel plate. It is the same graph as FIG. 27 at the time of supplying a high frequency current regarding the hand dryer of this invention which employ | adopted the IH heater using a SUS430 stainless steel plate. It is the same graph as FIG. 26 at the time of supplying a high frequency current regarding the hand-drying apparatus of this invention which employ | adopted the IH heater using a SUS304 stainless steel plate. It is the same graph as FIG. 27 at the time of supplying a high frequency current regarding the hand-drying apparatus of this invention which employ | adopted the IH heater using a SUS304 stainless steel plate. It is the same graph as FIG. 26 at the time of supplying a direct current regarding the hand-drying apparatus of this invention which employ | adopted the IH heater using a SUS430 stainless steel plate. It is the same graph as FIG. 27 at the time of supplying a direct current regarding the hand-drying apparatus of this invention which employ | adopted the IH heater using a SUS430 stainless steel plate. It is a graph which shows the relationship between IH electric power ratio and the difference (temperature rise) of intake air temperature and ejection temperature. It is the graph which plotted the average temperature of the surface of the stainless steel plate of an IH heater when an operation | movement and a stop are repeated 60 times after pre-heat processing. It is a graph which shows the relationship between IH electric power ratio and reserve electric power.

  Hereinafter, an embodiment of a hand dryer according to the present invention will be described with reference to the accompanying drawings. In the description of the embodiments below, terms representing directions (for example, “X direction”, “Y direction”, “Z direction”, “upward”, “downward”, etc.) are used as appropriate for easy understanding. These are for illustration purposes only, and these terms do not limit the invention. Moreover, in each accompanying drawing, the same component is illustrated using the same referential mark.

Embodiment 1 FIG.
FIG. 1 is a side view showing a hand drying device 1 according to Embodiment 1 of the present invention. The hand-drying apparatus 1 of Embodiment 1 is roughly divided into a housing 2, a blower 3 that is a high-pressure air generator that generates high-pressure air, and induction heating that is an induction heating apparatus (Induction Heating Apparatus) for heating the air. A heater (hereinafter simply referred to as “IH heater”) 4 and a control circuit 5 for controlling the blower 3 and the IH heater 4 are provided.

  The housing 2 includes an intake port 6 for taking in ambient air, a plurality of jet ports (spout nozzles) 7 for jetting air heated by the IH heater 4 to the outside, and a space between the intake port 6 and the jet port 7. And a duct 8 (broken line in FIG. 1) in fluid communication. The IH heater 4 and the blower 3 are disposed in a duct 8, and the duct 8 communicates with a flow path of the IH heater 4 described later. The housing 2 forms a hand insertion space 9, where the user's hand can be dried by the jet stream ejected from the jet outlet 7, and whether the user's hand has been inserted into the hand insertion space 9. A hand sensor (not shown) for detecting whether or not is provided is provided. The hand sensor may be any suitable sensor apparent to those skilled in the art, such as infrared LEDs and photodiodes, and is configured to communicate with the control circuit 5.

  In the hand dryer 1 configured as described above, when the hand sensor detects that the user's hand has been inserted into the hand insertion space 9, the hand sensor transmits a detection signal to the control circuit 5, and the control circuit 5 And the IH heater 4 is operated. When the blower 3 and the IH heater 4 are operated, the ambient air is sucked into the duct 8 from the intake port 6 as shown by the arrows in FIG. 1, and the air in the flow path communicating with the duct 8 is heated by the IH heater 4. Then, the heated air is jetted from the jet port 7 as a jet stream through the branched duct 8. Similarly, when the hand sensor stops detecting the user's hand, the control circuit 5 controls the IH heater 4 and the blower 3 to stop.

  The jet stream ejected from the ejection nozzle 7 has a wind speed of 50 to 120 m / s and blows off water droplets adhering to the user's hand. Also, since the jet stream is heated by the IH heater 4, even when the ambient air temperature is low, the user is not uncomfortable, the evaporation of water droplets attached to the hand is promoted, and the drying time is shortened. can do. The temperature of ambient air is detected using a temperature sensor (not shown), and the control circuit 5 may be configured to control the output of the IH heater 4 so as to reach a predetermined temperature of the jet stream that the user feels comfortable with. Good.

  2 is a perspective view showing a specific structure of the IH heater 4 according to Embodiment 1, and FIG. 3 is an enlarged perspective view of a part indicated by a broken line in FIG. As shown in FIG. 2, the IH heater 4 includes an outer frame 10 having an opening 12 penetrating in the Z direction, and a plurality (15 in FIG. 1) arranged substantially parallel to the YZ plane. And a heater cell 14. As shown in FIG. 3, each heater cell 14 includes a heating coil (induction coil) 20 and a pair of metal plates (objects to be heated) 30 sandwiching the heating coil (induction coil). FIG. 3 does not show the right metal plate 30 of the heater cell 14 shown on the rightmost side. At this time, a plurality of flow paths 40 extending in the Z direction are formed between the metal plate 30 of the adjacent heater cell 14 and the outer frame 10 (not shown in FIG. 3). The housing 2 communicates with the intake port 6 and the jet port 7.

  When a high frequency current is supplied via the control circuit 5, the heating coil 20 receives an alternating current to form a high frequency magnetic field, and the metal plate 30 generates heat due to an eddy current generated internally by the high frequency magnetic field. Since the heated metal plate 30 is in direct contact with the air flowing in the flow path 40, the air can be heated extremely efficiently and with high responsiveness.

  As described above, when the blower 3 is activated, a high-speed air flow is formed in the flow path 40 between the heater cells 14, and when the high-frequency current is supplied to the heating coil 20, the metal plate 30 generates heat and the metal plate 30 is heated. The air in the facing channel 40 is heated. The width of each flow path 40 (interval between adjacent heater cells 14) needs to be designed so that the pressure loss does not increase and the wind speed of the airflow does not decrease. In the IH heater 4 of this embodiment, about 1 mm to 5 mm. , Preferably about 3 mm.

  The heating coil 20 is made of an arbitrary conductive material, but is electrically insulated from the metal plate 30. The heating coils 20 of the three adjacent heater cells 14 are connected in parallel, and one terminal 22a in FIG. 3 is connected to a wiring terminal 17a above the wiring board 16 attached on the outer frame 10 shown in FIG. The other terminal 22 b is connected to a wiring terminal 17 b below the wiring board 16. In addition, the plurality of wiring terminals 17a and 17b of the wiring board 16 are connected in series, and the IH heater 4 includes five sets of three heating coils 20 connected in parallel as shown in the circuit diagram of FIG. They are wired in series and are electrically connected to the control circuit 5 via the external terminals 18a and 18b.

More specifically, as shown in FIGS. 5A to 5C, the heating coil 20 according to the first embodiment has a spiral shape made of a substrate 23 made of glass epoxy resin and a metal such as copper thereon. And a thin film (conductive layer) 24 patterned. Further, the heating coil 20 has a polypropylene resin film 25 and a glass epoxy resin film 26 on the metal thin film 24 in order to be electrically insulated from the metal plate 30 and thermally protected (FIG. 5C). The metal thin film 24 , the polypropylene resin film 25, and the glass epoxy resin film 26 are preferably formed on both surfaces of the substrate 23 and efficiently heat the pair of metal plates 30 that sandwich the heating coil 20 (polypropylene resin). The film 25 is not hatched to make the drawing easier to understand.) At this time, in FIG. 5C, the metal plating processed through hole 27 is provided in the vicinity of the center of the substrate 23 and the metal thin film 24 so that the metal thin films 24 provided on both surfaces of the substrate 23 are electrically connected to each other. Is provided. Thus, current flows from the terminal 28a provided on the front surface side of the substrate 23 to the metal thin film 24, the through hole 27, the metal thin film 24 on the back surface side, and the terminal 28b. The metal thin films 24 provided on both surfaces of the substrate 23 are patterned so that their spiral directions are opposite to each other (clockwise and counterclockwise) in order to match the direction of the magnetic field to be formed. Yes.

  Although not limited to this, the size of the metal plate 30 may be 60 mm × 60 mm × 0.6 mm, and the substrate 23 of the heating coil 20, the metal thin film 24, the polypropylene resin film 25, and the glass epoxy resin film. The thickness of 26 may be 400 μm, 105 μm, 100 μm and 100 μm, respectively.

  The material constituting the metal plate 30 may be any material as long as it is heated by the heating coil 20, but is preferably a stainless steel plate, and in particular, specified by JIS (Japanese Industrial Standard) standards. The stainless steel plate SUS430 is particularly preferable because it hardly corrodes, has high magnetic permeability, and is inexpensive. In addition, the metal plate 30 may be an iron plate, a silicon steel plate, a nickel plate, a permalloy plate, and the like, and the iron plate and the silicon steel plate are useful because they are inexpensive and have high magnetic permeability. It is preferable to perform surface treatment by plating or coating a non-corrosive metal having a high conductivity.

  When the surface treatment is performed, the metal plate 30 such as an iron plate that generates heat by electromagnetic induction heating does not directly contact the fluid passing through the flow path 40. However, if the thickness of the metal plating or coating is sufficiently thin Does not adversely affect thermal conductivity. Similarly, a resin having a small thermal conductivity may be coated on the metal plate 30 such as an iron plate. The metal plate 30 may be a nonmagnetic metal such as a nonmagnetic stainless steel plate, a copper plate, or an aluminum plate. Even in the case of a nonmagnetic material, the metal plate 30 can be heated by appropriately adjusting the driving conditions such as increasing the frequency. it can.

  FIG. 6 is a drive circuit diagram for supplying a high-frequency current to the heating coil 20. The heating coil 20 is represented by an equivalent circuit of an inductance Ls and a resistance Rs connected in series, and corresponds to a portion surrounded by a broken line in FIG. As described above, the IH heater 4 may be configured using a plurality of heating coils 20, and the inductance Ls and the resistance Rs represent the entire inductance and resistance of the plurality of heating coils 20 of the IH heater 4. Shall. The heating coil 20 constitutes an LC resonance circuit together with a capacitor C1 connected in parallel to this, and includes an IGBT (Insulated Gate Bipolar Transistor) element 31 and an FWD (Free Wheel Diode) element 32 connected in parallel in opposite directions. Connected in series. A current from a normal household power supply 34 (AC voltage: 100 V or 200 V) is rectified into a DC current by a rectifier circuit (AC / DC converter) 36 such as a diode bridge, and the DC current is smoothed by a capacitor C2. The direct current supplied to the heating coil 20 does not necessarily need to be smoothed, and the heating coil 20 may be directly supplied with power from a full-wave rectified or half-wave rectified power source (not shown) or a direct-current power supply.

  The IGBT element 31 is switched on and off by a rectangular wave gate control signal 33 from the control circuit 5. When the IGBT element 31 is in the ON state, the direct current from the rectifier circuit 36 and the capacitor C2 is supplied to the heating coil 20, that is, flows through the inductance Ls, the resistor Rs, and the IGBT element 31. When the IGBT element 31 is in the OFF state, the inductance Ls keeps flowing current, so that current flows in the closed loop including the capacitor C1 and charges the capacitor C1. Then, the voltage of the capacitor C1 rises, the current flowing through the inductance Ls decreases, and the discharge current from the capacitor C1 eventually flows in the opposite direction to the inductance Ls and the resistor Rs. Thereafter, when the IGBT element 31 is switched to the ON state again, a forward current flows through the inductance Ls and the resistor Rs. By repeating the switching operation of the IGBT element 31, a sawtooth AC current as shown in FIG. 7 can be passed through the heating coil 20. As described above, the heating coil 20 receives an alternating current to form a high-frequency magnetic field, and the metal plate 30 generates heat due to an eddy current generated internally by the high-frequency magnetic field. Since the metal plate 30 that has generated heat is in direct contact with the air in the flow path 40 to be heated, the air can be heated extremely effectively and with high responsiveness.

  The drive signal input to the IGBT element 31 includes the inductance Ls and resistance Rs of the heating coil 20 used, the capacitance of the capacitor C1, the oscillation frequency, the power supply voltage, the expected output heat amount of the IH heater 4 and the circuit configuration. It can adjust suitably based on these. In other words, the drive condition of the IGBT element 31 can be adjusted according to the expected output heat amount of the IH heater 4. For example, as shown in FIG. 4, in an IH heater 4 configured by connecting five sets of three adjacent heating coils 20 connected in parallel, the inductance Ls of each heating coil 20 is 33 μH and the resistance Rs is 3 mΩ. When the capacitance of the capacitor C1 is 0.3 μF, the oscillation frequency is 20 kHz (period 50 μs), the ON time of the drive signal input to the IGBT element 31 is 37 μs, and the OFF time is 13 μs, the power supply voltage 100 V is used. Thus, power consumption (output heat amount) of about 1 kW can be obtained. The power consumed by the IH heater 4 can be adjusted by controlling the DC voltage output from the rectifier circuit 36. Preferably, the OFF time of the IGBT element 31 is fixed and the ON time is adjusted. Can be easily controlled.

  Note that the drive circuit of the IH heater 4 is not limited to this, and a half-bridge circuit or a full-bridge circuit may be used, and drive circuits used in various induction heating apparatuses can be used.

Embodiment 2. FIG.
A second embodiment of the hand dryer according to the present invention will be described with reference to FIGS. Since the hand dryer 1 of Embodiment 2 is the same as that of Embodiment 1 except for the structure of the IH heater 4, the description of the overlapping contents is omitted.

FIG. 8 is a cross-sectional view of the IH heater 4 according to the second embodiment cut along the XY plane, and FIG. 9 is an exploded view of each heater cell 14. As in the first embodiment, the IH heater 4 shown in FIG. 8 includes an outer frame 10 having an opening 12 penetrating in the Z direction, and four heater cells 14 arranged substantially parallel to the YZ plane. Have. Each heater cell 14 includes a heating coil (induction coil) 20 and a pair of metal plates (heated bodies) 30 that sandwich the heater coil 14. Each heating coil 20 is connected in series and driven by the control circuit 5. The number of heater cells 14 is not limited to four, and an arbitrary number of heater cells 14 may be connected in series. Moreover, you may connect the group which connected the some heater cell 14 in parallel like Embodiment 1 in series (for example, 5 sets) in series.

  The flow path 40 of the second embodiment is formed between the adjacent heater cells 14 and the frame 10 as in the first embodiment, and the interval between the adjacent heater cells 14 is about 1 mm to 5 mm, preferably about 3 mm. The heating coil 20 is formed substantially parallel to the YZ plane.

  However, each heating coil 20 of the second embodiment is different from the first embodiment in that, as shown in FIGS. 8 and 9, between the pair of metal plates 30, a conductive wire 42 coated with an insulating film is provided as a heater cell. After extending to the center of 14, it is formed by winding around it. Any conductive wire 42 coated with an insulating film can be used, but an enameled wire or a formal wire may be used.

  Moreover, in order to insulate the heating coil 20 and the metal plate 30 reliably, you may provide the insulating sheet or space which is not shown in figure. Furthermore, the metal plate 30 may be formed using a metal material such as iron, copper, or aluminum in addition to stainless steel, as in the first embodiment.

  In general, electric power consumed by the IH heater 4 (heater cell 14) according to the present invention is converted into Joule heat (Hc) generated from the heating coil 20 itself and Joule heat (Hm) generated from the metal plate 30. Here, if the ratio {Hm / (Hc + Hm)} of the Joule heat (Hm) generated in the metal plate 30 to the total Joule heat (Hc + Hm) is defined as the IH power ratio, the IH power ratio is the resistance value (Rc) of the heating coil 20. ) And the resistance value {Rm / (Rc + Rm)} represented by the resistance value (Rm) of the metal plate 30. That is, in order to suppress Joule heat (Hc) generated from the heating coil 20 itself as much as possible and maximize Joule heat (Hm) generated in the metal plate 30 to efficiently heat the fluid in the flow path 40, the IH power ratio Alternatively, it is necessary to appropriately design the heating coil 20 and the metal plate 30 so that the resistance ratio {Rm / (Rc + Rm)} is as large as possible.

  As described above, when the heating coil 20 is formed by winding the conductive wire 42 coated with an insulating film, the cross-sectional area of the conductive wire 42 is easily increased and the resistance value of the heating coil 20 is decreased. be able to. On the other hand, in order to reduce the resistance value of the heating coil 20 according to the first embodiment, it is necessary to form the metal thin film 24 thick, but such a metal thin film 24 is difficult to process. Therefore, the heating coil 20 according to the second embodiment can heat the air in the flow path 40 more efficiently by using a simpler configuration than that of the first embodiment and increasing the IH power ratio. For example, when the heating coil 20 is manufactured by winding a copper wire having a diameter of about 1 mm for 25 turns, the IH power ratio of the heating coil 20 is 71.9% in the first embodiment, but the second embodiment Then, it can be improved to 98%.

  The heating coil 20 according to the second embodiment may have an arbitrary planar shape such as a circle in the YZ plane, but the entire surface of the metal plate 30 generates heat, and the metal plate 30 and the air In order to maximize the contact area, it is preferable to have the same planar shape as the metal plate 30.

  Further, in the heating coil 20 according to the second embodiment, the conductive wire 42 is wound once in FIGS. 8 and 9, but may be wound twice as shown in FIGS. 10 and 11.

Embodiment 3 FIG.
A third embodiment of the hand dryer according to the present invention will be described with reference to FIGS. Since the hand dryer 1 of Embodiment 3 is the same as that of Embodiment 2 except the structure of each heater cell 14, description is abbreviate | omitted about the overlapping content.

  FIG. 12 is a cross-sectional view of the IH heater 4 according to the third embodiment, and FIG. 13 is an exploded view of each heater cell 14 and is the same as FIGS. 8 and 9 respectively. Unlike the second embodiment, the heater cell 14 of the third embodiment is configured by providing a support column 44 between a pair of metal plates 30 and winding a conductive wire 42 coated with an insulating film around it. The

  The struts 44 employed in the heater cell 14 of the third embodiment may be formed integrally with the pair of metal plates 30 using the same material, or after being formed using a material different from the metal plate 30, You may connect to the metal plate 30 using arbitrary connection means, such as welding, screwing, or an adhesive agent. As described above, the heater cell 14 according to the third embodiment has a form like a bobbin used in a sewing machine.

  When the support 44 is made of a magnetic metal, the support 44 itself generates heat upon receiving the AC magnetic field of the heating coil 20, but the heat transfer efficiency of the support 44 is not directly in contact with the air flowing through the flow path 40. Is inferior to the metal plate 30. Therefore, in order for the metal plate 30 to generate heat more preferentially by receiving the alternating magnetic field of the heating coil 20, the support column 44 is preferably made of a nonmagnetic material such as copper, aluminum, resin, or ceramic.

  In addition, the heating coil 20 of the third embodiment may have an arbitrary planar shape such as a circle in the YZ plane as in the second embodiment, but the entire surface of the metal plate 30 generates heat, In order to maximize the contact area between the metal plate 30 and air, the metal plate 30 is preferably formed to have the same planar shape as the metal plate 30. Therefore, the support 44 is formed to have the same planar shape as that of the metal plate 30 so that the planar shape of the conductive wire 42 wound around the support 44 has the same (similar) shape as that of the metal plate 30. The

  By the way, in the said embodiment, the outer frame 10 can be formed using arbitrary materials, and a space | interval and space | interval between the side edge parts 37 (both ends of a Y direction, refer FIG. 12) of the metal plate 30 are possible. A spacer may be provided, but when the outer frame 10 is formed of a non-magnetic material or is substantially separated from the metal plate 30, the magnetic flux (magnetic field) generated by the heating coil 20 is non-magnetic. The body cannot pass through the outer frame 10 or the space, and a leakage magnetic flux is generated. At this time, the efficiency with which the metal plate 30 generates heat by the alternating magnetic field generated by the heating coil 20 is reduced by the leakage magnetic flux. Therefore, the heater cell 14 includes a metal tube (a body to be heated) 38 made of a magnetic material and integrally formed in a cylindrical shape so as to surround the heating coil 20 as shown in FIG. 14 instead of the pair of metal plates 30. You may do it. Thereby, the leakage magnetic flux in XY plane can be suppressed and more efficient heat_generation | fever of the to-be-heated body 38 can be assisted. Instead of the integrally formed hollow rectangular parallelepiped body to be heated 38, a separate side wall (not shown) for connecting the side end portions 37 of the pair of metal plates 30 is provided, and leakage magnetic flux is provided. It may be suppressed.

Embodiment 4 FIG.
Embodiment 4 of the hand dryer according to the present invention will be described with reference to FIGS. Since the hand dryer 1 of Embodiment 4 is the same as that of Embodiment 1 except the structure of the IH heater 4, description is abbreviate | omitted about the overlapping content.

  FIG. 15 is a cross-sectional view taken along the XY plane of the IH heater 4 according to the fourth embodiment, and FIG. 16 is an exploded view showing a part of the IH heater 4. The IH heater 4 shown in FIGS. 15 and 16 generally includes a plurality (five in FIG. 15) of hollow metal tubes (heated bodies) 50 each having a flow path 40 extending through in the Z direction, and YZ. And a plurality (four in FIG. 15) of heating coils 20 arranged substantially parallel to the plane. Each heating coil 20 is electrically connected in series and is driven by the control circuit 5. The number of heating coils 20 is not limited to four, and an arbitrary number of heating coils 20 may be connected in series. Further, as shown in the first and second embodiments, a plurality of heating coils 20 are connected in parallel, a group of a plurality of heating coils 20 connected in parallel is connected in series, or parallel connection and series connection are arbitrary. You may connect in combination. At this time, the directions of the magnetic fields generated by the plurality of heating coils 20 are preferably the same. Each metal tube 50 has a flat surface 52 substantially parallel to the YZ plane, and the flat surface 52 of the adjacent metal tube 50 is formed by a column 44 similar to that of the third embodiment provided therebetween. It is connected. That is, the heating coil 20 of the fourth embodiment is formed by winding the conductive wire 42 with an insulating coating around the support pole 44 as in the third embodiment.

  Unlike the first embodiment, the IH heater 4 according to the fourth embodiment has a flow path 40 formed in the hollow space of the metal tube 50, and the outer frame 10 is not necessarily required and can be omitted. Can be manufactured at a low cost with a simpler configuration. The IH heater 4 according to the first to third embodiments is manufactured by incorporating a plurality of individually manufactured heater cells 14 into the outer frame 10, whereas the IH heater 4 according to the fourth embodiment Since it is manufactured by winding the conductive wire 42 with insulating coating around the pillars 44 of the plurality of connected metal tubes 50, the manufacturing is easy and the manufacturing cost can be further reduced.

  In the IH heater 4 thus configured, when a high frequency current is supplied to the heating coil 20, magnetic lines of force are generated, and the eddy current induced thereby is formed in the metal tube 50 to generate heat. Since the heated metal tube 50 is in direct contact with the air flowing through the flow path 40, the air can be heated extremely efficiently and with high responsiveness.

  Further, the IH heater 4 of the fourth embodiment may have a through fixture 54 that extends in the X direction and penetrates the plurality of metal tubes 50 and the columns 44 as shown in FIG. The penetration fixture 54 is configured using a fixing means (bolt, nut) 55 such as a general screw, and is fixed to a series of metal tubes 50. Thus, the IH heater 4 can be mechanically reinforced and the assembly workability at the time of manufacture can be improved.

  Furthermore, although the heated object of the IH heater 4 of Embodiment 4 was demonstrated as the metal pipe 50, as shown in FIG. 18, even if it uses the same pair of metal plates 30 as Embodiments 1-3. Good. At this time, a spacer 56 may be separately provided around the penetration fixture 54 in the flow path 40 through which air flows. If necessary, the spacer 56 can be formed of a nonmagnetic material, and the metal plate 30 can be preferentially heated by the penetration fixture 54 by the AC magnetic field of the heating coil 20.

Embodiment 5 FIG.
Embodiment 5 of the hand dryer according to the present invention will be described with reference to FIGS. Since the hand dryer 1 of Embodiment 5 is the same as that of Embodiment 4 except the structure of the IH heater 4, description is abbreviate | omitted about the overlapping content.

  FIG. 19 is a perspective view of the IH heater 4 according to the fifth embodiment. The IH heater 4 in FIG. 19 has a plurality (three in FIG. 19) of heater cells 14, and each heater cell 14 has a hollow metal tube (heated object) 50 having a flow path 40 extending through in the Z direction. And a heating coil 20 around which an electrically conductive wire 42 with an insulating coating is wound around its outer surface 58. The conductive lines 42 of the heater cells 14 are connected in series and driven by a current supply circuit (not shown in FIG. 19). Note that the number of heater cells 14 is not limited to three, and an arbitrary number of heater cells 14 may be connected in series. A plurality of heater cells 14 may be connected in parallel, or may be connected in any combination of parallel connection and series connection. Each metal tube 50 has a rectangular parallelepiped shape in FIG. 19, but may have an arbitrary hollow shape such as a cylindrical shape. In the electrothermal converter 1 of the fifth embodiment, the flow path 40 is formed in the hollow space of the metal tube 50 as in the fourth embodiment, and the outer frame 10 is not necessarily required and can be omitted.

  According to the IH heater 4 of the fifth embodiment configured in this way, as with the previous embodiments, when a high frequency current is supplied to the heating coil 20, magnetic field lines are generated, and the metal tube 50 is induced thereby. An eddy current is formed and heat is generated. Since the heated metal tube 50 is in direct contact with the air flowing through the flow path 40, the air in the flow path 40 can be heated very efficiently and with good responsiveness.

  Since the heating coil 20 of the IH heater 4 shown in FIG. 19 is formed by winding the conductive wire 42 clockwise as viewed from above, a current flows in the direction indicated by the arrow in the figure. Each heater cell 14 has a magnetic pole with the N pole on the bottom and the S pole on the top. However, in order to avoid the magnetic fluxes of the adjacent heater cells 14 from interfering with each other, it is preferable to make the magnetic poles of the adjacent heater cells 14 different from each other. In order to realize this, as shown in FIG. 20, among the three continuous heater cells 14, the conductive wire 42 of the central heater cell 14 is wound in the counterclockwise direction along the outer surface 58 of the metal tube 50. The That is, the heater cell 14 disposed in the center is configured such that the N pole is formed upward, and the other adjacent heater cells 14 are formed such that the S pole is formed upward. In this way, it is possible to provide the IH heater 4 capable of efficiently converting electromagnetic field energy into heat energy without interfering with the magnetic fluxes of adjacent heater cells 14.

  Moreover, although the heating coil 20 of Embodiment 5 heats the metal tube 50 disposed on the inner side, the AC magnetic field generated by the heating coil 20 is naturally formed also on the outer side of the heating coil 20. The Therefore, as shown in FIGS. 21 and 22, another metal tube (hollow conductor) 60 is disposed outside the heating coil 20, so that the AC magnetic field energy formed outside the heating coil 20 can be efficiently reduced. It is preferable to convert it into thermal energy. The outer metal tube, that is, the hollow conductor 60 is preferably made of the same metal material as the metal tube 50 provided inside the heating coil 20. At this time, the inner flow path 40 formed inside the inner metal tube 50 and the outer flow path 41 formed outside the hollow conductor 60 and inside the frame 10 in FIG. 21 are formed. . The air flowing through the inner channel 40 and the outer channel 41 merges and is guided into the duct 8 of the hand dryer 1. In this way, it is possible to realize the IH heater 4 that can convert the alternating magnetic field generated by the heating coil 20 into heat energy very efficiently.

  In the embodiment described so far, the surfaces (the flat surfaces of the pair of metal plates 30, the inner surfaces of the metal tubes 50, and the outer surfaces of the hollow conductors 60) forming the flow path 40 are air pressure loss. However, it is preferable to have a form in which the surface area is enlarged in order to further improve the heat dissipation effect. That is, as shown in FIGS. 23A and 23B, the surface forming the flow path 40 has irregularities in a cross section in a direction substantially perpendicular to the flow path 40 (that is, the YZ plane). It is preferable that it is comprised so that it may have.

Embodiment 6 FIG.
Embodiment 6 of the hand dryer according to the present invention will be described with reference to FIGS. The hand dryer 1 of the sixth embodiment has the same configuration as that of the first embodiment except that the IH heater 4 is disposed at two locations in the duct 8 between the blower 3 and the injection nozzle 7. Therefore, the description of the overlapping contents is omitted.

  As described above, the IH heater 4 according to the sixth embodiment is disposed at two locations in the duct 8 between the blower 3 and the injection nozzle 7 as shown in FIG. 7 is arranged adjacent to. However, when the IH heater 4 is disposed between the blower 3 and the injection nozzle 7, the effect of the present invention according to the sixth embodiment can be obtained even when only one is provided.

According to the hand dryer 1 of the first embodiment shown in FIG. 1 , the IH heater 4 is disposed between the air inlet 6 and the blower 3, so that the air heated by the IH heater 4 is converted into the duct 8. While passing through the inside, the duct 8 is deprived of heat, and when it is ejected from the ejection nozzle 7, a sufficiently high temperature may not be maintained. Therefore, in order to ensure the temperature of the jet airflow ejected from the ejection nozzle 7, the temperature of the metal plate 30 is maintained at a substantially high temperature (for example, 120 ° C.) during the standby of the hand dryer 1, and the duct 8. And it was necessary to preheat the air in the flow path 40.

  According to the IH heaters 4 of the first to fifth embodiments described so far, the heated objects such as the metal plate 30 and the metal tube 50 are in direct contact with the air flowing through the flow path 40, so that the air is extremely efficient. And with good responsiveness. Therefore, it is not necessary to preheat the air in the flow path 40, and the air can be instantaneously heated to a temperature at which it can be used immediately. Then, by disposing the IH heater 4 adjacent to the blower 3, it is possible to prevent the duct 8 from taking heat away. Thus, since it is not necessary to preheat the air during standby, power consumption during standby can be minimized.

  Even if the air must be preheated during standby, the power consumption during standby can be substantially reduced by reducing the preheating time. In Embodiment 1, it is detected whether a user's hand was inserted in the hand insertion space 9 using the hand sensor attached to the hand dryer 1, and the hand dryer 1 operate | moves according to this. So that it is controlled. In the hand dryer 1 of the sixth embodiment, in addition to this hand sensor, the user uses a human sensor (not shown) installed in the room in the bathroom where the hand dryer 1 is installed. It may be controlled to detect that it has entered the bathroom and start preheating the air in the flow path 40 in response to this. In addition to human sensors, it responds to signals from photo sensors that detect that the lighting in the bathroom is lit, sensors that work with the lighting switch, and sensors that detect that water has been used in the bathroom. And you may comprise the hand-drying apparatus 1 so that the air in the flow path 40 may begin to preheat.

  FIG. 25 is an enlarged view of a part of the housing 2 including the ejection nozzle 7 of the hand dryer 1. 25 corresponds to the IH heater 4 viewed from the Z direction in FIG. 19 or 20. In FIG. 19, the air is directly ejected from the flow path 40 of each heater cell 14 of the IH heater 4, that is, each opening of each heater cell 14 functions as the ejection nozzle 7. According to the hand dryer 1 configured as described above, it is possible to prevent the duct 8 from taking heat away from the air heated by the IH heater 4.

  When the IH heater 4 is generated adjacent to the ejection nozzle 7 or when the opening of each heater cell 14 functions as the ejection nozzle 7, the alternating current magnetic field from the heating coil 20 is applied to a wristwatch worn by the user. 25, a magnetic shield plate 64 using a magnetic material such as ferrite is disposed around the IH heater 4 to shield the AC magnetic field from the heating coil 20 as shown in FIG. It is preferable to do.

  An experiment was conducted to compare the performance of the hand dryer 1 using the IH heater of the present invention and the conventional hand dryer using a sheathed heater.

  The IH heater 4 used here is the same as that shown in FIG. 2, but four sets of heater cells 14 connected in parallel are connected in series, and each heater cell 14 is heated. The coil 20 has a copper thin film 24 patterned in a spiral pattern on both surfaces of a substrate 23 (see FIG. 5). Each of the heating coils 20 had 25 turns and the thickness of the copper thin film 24 was 35 μm. At this time, the resistance value of the heating coil 20 was 1.19Ω when measured at a frequency of 20 kHz using an impedance analyzer. The metal plate 30 was formed into a size of 60 mm × 60 mm × 1 mm using two types of stainless steel, SUS430 (JIS standard) which is magnetic stainless steel and SUS304 (JIS standard) which is nonmagnetic stainless steel (see FIG. 3). . The resistance values of the heater cell 14 in which the heating coil 20 was sandwiched between a pair of SUS430 stainless steel plates and SUS304 stainless steel plates were similarly measured at a frequency of 20 kHz, and were 4.24Ω and 2.20Ω, respectively. Since these resistance values are the total value of the resistance value of the heating coil 20 and the resistance value of the metal plate (stainless steel plate) 30, when the resistance value of the heating coil 20 is subtracted from the total resistance value, the SUS430 stainless steel plate and The resistance values of the SUS304 stainless steel plate are 3.05Ω and 1.01Ω, respectively (note that the electrical resistivity of the SUS430 stainless steel plate and the SUS304 stainless steel plate is 60 μΩcm and 72 μΩcm, respectively).

In general, electric power (electric energy) supplied to the heating coil is consumed by the heating coil 20 and each stainless steel plate 30 and converted into thermal energy. However, Joule heat (Hc) generated from the heating coil 20 and the stainless steel plate 30 are converted into heat energy. Is defined as IH power ratio {Hm / (Hc + Hm)}. At this time, the IH power ratio may be considered to be equal to the ratio of the resistance value of the stainless steel plate to the total value of the resistance value of the heating coil and the resistance value of the stainless steel plate. The ratio of the thermal energy (W ₄₃₀ , W ₃₀₄ ) converted by the SUS430 stainless steel plate and the SUS304 stainless steel plate to the entire supplied power (Wt), that is, the IH power ratio is the resistance value of the heating coil and the resistance value of the stainless steel plate. The ratio of the resistance value of the stainless steel plate to the total value is 71.9% (W ₄₃₀ / Wt) and 45.9% (W ₃₀₄ / Wt), respectively. Therefore, as the IH power ratio is larger, the electric-thermal energy conversion efficiency can be increased. Therefore, the metal plate 30 is preferably formed using magnetic stainless steel SUS430 rather than nonmagnetic stainless steel SUS304. In other words, by suppressing the resistance value of the heating coil 20 as much as possible as compared with the resistance value of the stainless steel plate, the electric-thermal energy conversion efficiency of each heater cell 14 can be remarkably improved.

  For example, in the hand dryer that employs the conventional sheathed heater described in Patent Document 1, the waiting sheathed heater is 1100 W so that the temperature of the heat storage and radiation fins disposed adjacently is maintained at 200 ° C. The power is intermittently supplied. In order to supply power continuously and maintain the temperature of the sheathed heater at 200 ° C., 120 W of electric power was required.

  Then, after the temperature of the sheathed heater was stabilized at 200 ° C. (pre-heat treatment), an operation test was repeated in which the operation for 10 seconds and the standby for 10 seconds were repeated. During operation, 370 W of power was supplied to the sheathed heater and 730 W of power was supplied to the blower to form a jet stream. During standby, the blower 3 was stopped and 1100 W of power was supplied to the sheathed heater. At this time, in a conventional hand drying apparatus using a sheathed heater, the temperature of the sheathed heater, the temperature of the jet air current (ejection temperature) and the temperature of the outside air to be sucked (intake air temperature) are measured, The graph of FIG. 26 was obtained. Similarly, in this conventional hand dryer, after the temperature of the sheathed heater is stabilized at 200 ° C., the intake air temperature and the ejection temperature that fluctuate in 10 seconds during operation at the first operation, the fifth operation, and the 60th operation. The difference (temperature rise) was measured and the graph of FIG. 27 was obtained.

  On the other hand, in the hand dryer 1 using the IH heater of the present invention, the standby IH heater is supplied with a high-frequency current so that the temperature of the stainless steel plate 30 is maintained at 120 ° C. for preheating, and SUS430 stainless steel. The IH heater using a plate required 48 W, and the IH heater using a SUS304 stainless steel plate required 60 W. Note that the power loss due to the circuit supplying the high-frequency current is not included in these. As a comparative example, when a direct current was supplied to an IH heater using a SUS430 stainless steel plate and the temperature of the stainless steel plate was maintained at 120 ° C., 82 W of power was required.

  These hand dryers 1 were subjected to an operation test in which 10 seconds of operation and 10 seconds of standby were repeated as described for the hand dryer using a conventional sheathed heater. That is, high-frequency power of 304 W and 945 W was supplied to the IH heaters in operation and standby, respectively, by subtracting power loss due to the current supply circuit.

  Thus, when a high frequency current is supplied to the IH heater 4 using the SUS430 stainless steel plate 30, the temperature of the heater cell 14 (IH heater temperature (center)) arranged in the center of the IH heater 4 (the tenth from one end), The temperature (IH heater temperature (end)) of the heater cell 14 arranged at the end of the IH heater 4 (first from one end), the temperature of the jet air flow (ejection temperature), and the temperature of the outside air to be sucked (intake air temperature) The graph of FIG. 28 showing the change over time of) was obtained. In addition, in the hand dryer that supplies high-frequency current to the IH heater 4 using the SUS430 stainless steel plate 30, the intake air temperature and the ejection temperature during the first operation, the fifth operation, and the 60th operation after the pre-heat treatment as in FIG. FIG. 29 showing how the difference (temperature rise) changes in 10 seconds during operation was obtained.

  Moreover, regarding the hand dryer which supplied the high frequency current to the IH heater 4 using the SUS304 stainless steel plate 30, FIG. 30 and FIG. 31 which are the same graphs as FIG. 28 and FIG. 29 were obtained. Furthermore, when a direct current was supplied to the IH heater 4 using the SUS430 stainless steel plate 30, the graphs of FIGS. 32 and 33 were obtained.

  Referring to FIGS. 26 to 33, a hand dryer using a conventional sheath heater, a hand dryer using an IH heater 4 according to the present invention supplied with a high frequency power source using a SUS430 stainless steel plate and a SUS304 stainless steel plate. The device 1 and the hand dryer using the IH heater 4 supplied with DC power using the SUS430 stainless steel plate 30 will be compared.

  During the first operation after the pre-heat treatment, the difference between the intake air temperature and the ejection temperature (temperature increase) was the smallest in the conventional hand dryer, reaching 15 K after 3 seconds of operation and 19 K after 10 seconds ( FIG. 27). On the other hand, according to the hand drying apparatus 1 employing the IH heater 4 according to the present invention, the difference between the intake air temperature and the ejection temperature (temperature rise) reaches 30K after 1 to 2 seconds after the operation, and then drops slightly. After 2 seconds, it became 27-28K. Thus, the temperature rise by the conventional hand dryer at the first operation after the pre-heat treatment is smaller than that of the hand dryer 1 according to the present invention. This is because the efficiency of heat transfer from the sheathed heater to the air via the heat storage and radiating fins is not sufficient, and the temperature of the sheathed heater during standby needs to be kept very high (200 ° C.). The hand dryer comprises a hand dryer main body and a separate heating device including a sheathed heater. During standby, the lid provided between the hand dryer main body and the heater closes and the sheathed heater heats up. This is because the air in the main body of the hand dryer is not warmed in order to protect the main body of the hand dryer. On the other hand, according to the hand dryer 1 employing the IH heater 4 according to the present invention, the stainless steel plate 30 heated by the eddy current is in direct contact with the air flowing through the flow path 40, so that the air is Heating can be performed very efficiently and with high responsiveness. Thereby, the IH heater 4 according to the present invention can set the preheating temperature lower (for example, 120 ° C.) than the conventional hand dryer, and can substantially reduce energy consumption.

  Next, the difference (temperature rise) between the intake air temperature and the ejection temperature at the fifth and 60th operation after the preheat treatment is compared. The temperature rise at the time of the fifth operation is about 22 to 24 K in the conventional hand dryer using the sheathed heater, and about each in the hand dryer 1 using the SUS430 stainless steel plate and the SUS304 stainless steel plate supplied with the high frequency current. 27 to 28K and about 26 to 27K, and about 24K in the hand dryer supplied with DC power using a SUS430 stainless steel plate.

  Similarly, the temperature rise during the 60th operation after the pre-heat treatment is about 23K in the conventional hand drying device using the sheathed heater, and the hand drying device using the SUS430 stainless steel plate and the SUS304 stainless steel plate supplied with high frequency power. 1 was about 24K and about 22K, respectively, and about 17-18K in the hand dryer supplied with DC power using a US430 stainless steel plate.

  As described above, the IH heater 4 of the present invention, especially the IH heater 4 using SUS430, is equivalent to or more than the sheathed heater in spite of supplying less power than the power supplied to the conventional sheathed heater. An increase in temperature was obtained. In other words, the hand dryer employing the IH heater 4 according to the present invention has higher heat conversion efficiency than the conventional product. However, when a direct current was supplied to the IH heater 4 using SUS430, the temperature rise during the 60th operation after the pre-heat treatment was about 17 to 18 K, which was inferior to the conventional hand dryer.

As described above, the ratio of the Joule heat (Hm) generated in the stainless steel plate 30 to the total Joule heat (Hc + Hm) is defined as the IH power ratio {Hm / (Hc + Hm)}, and the IH power ratio, the intake air temperature, and the ejection temperature The graph of FIG. 34 which shows the relationship with the difference (temperature rise) of was obtained. Specifically, since the IH power ratio is proportional to the resistance ratio {Rm / (Rc + Rm)} represented by the resistance value (Rc) of the heating coil 20 and the resistance value (Rm) of the stainless steel plate 30, the SUS430 stainless steel is used. 1st, 5th and 60th after pre-heat treatment, in terms of the case of using the plate and SUS304 stainless steel plate (71.9% and 45.9% respectively) and the case of supplying DC power (0%) The temperature rise during operation was plotted. As can be seen from FIG. 34, the temperature rise during the first, fifth and 60th operations after the pre-heat treatment, that is, the temperature of the jet airflow increases in proportion to the IH power ratio.

  Since the air in the hand dryer 1 is warmed by the preheating, the temperature rise during the first operation after the preheat treatment does not increase significantly even if the IH power ratio increases. However, as the number of operations increases, the effect of preheating is diluted, and the temperature rise is highly dependent on the IH power ratio. That is, since the power supplied to the IH heater 4 is constant regardless of the IH power ratio, the amount of heat generated by the entire IH heater 4 is the same, but as shown in FIG. 34, the IH power ratio is large. The temperature (temperature rise) of the jet stream that is ejected increases. Therefore, the IH heater 4 according to the present invention is preferably as the IH power ratio is larger in the context of heating more efficiently.

  FIG. 35 is a graph plotting the average temperature of the surface of the stainless steel plate 30 of the IH heater 4 when the operation (10 seconds) and the stop (10 seconds) are repeated 60 times after the pre-heat treatment. As can be seen from FIG. 35, the average temperature of the SUS430 stainless steel plate with the high IH power ratio supplied with the high frequency current (71.9%) is the highest, and then the SUS304 stainless steel plate (45 0.9%) was high, and the average temperature of the SUS430 stainless steel plate (0%) supplied with DC power was low. From this result, the IH heater 4 according to the present invention is preferably as the IH power ratio is larger from the viewpoint of keeping the surface temperature of the stainless steel plate 30 high.

In order to increase the IH power ratio, the resistance of the heating coil 20 may be reduced. To that end, the thickness of the metal thin film 24 is increased to increase the cross-sectional area, and the number of turns of the heating coil 20 is increased. The total wiring length may be shortened, or the metal thin film 23 may be formed using a material having a small specific resistance. Moreover, the IH power ratio can be increased by forming the stainless steel plate 30 using a metal material having a higher magnetic permeability or a larger volume resistivity.

  In the IH heater 4 using the above-described SUS430 stainless steel plate and SUS304 stainless steel plate, the reserve power necessary to maintain these stainless steel plates 30 at 120 ° C. during the preheating is 48 W and 60 W, respectively, and a DC power supply is supplied. The reserve power of the IH heater 4 using the SUS430 stainless steel plate was 82W. FIG. 36 is a graph showing the relationship between these IH power ratios and standby power. As apparent from FIG. 36, the reserve power of the IH heater 4 is linearly reduced with respect to the IH power ratio. That is, the IH heater 4 according to the present invention is preferably as the IH power ratio is large in that the reserve power necessary for preheating the stainless steel plate 30 to a predetermined temperature is reduced and the energy consumption is reduced.

  In the above description, the stainless steel plate 30 of the IH heater 4 described above has a thickness of 0.6 mm or 1 mm and is configured to store heat by being heated by the heating coil 20 during standby, but is thicker. When formed, the heat storage effect is increased, and the power supplied to the heating coil 20 during operation can be reduced. On the other hand, when the power supply capacity of the hand dryer is not limited and the power that can be supplied to the heating coil 20 during operation can be sufficiently increased, the stainless plate 30 is made thinner and pre-heating is not performed. The surface temperature of the plate 30 can be increased more quickly. However, the eddy current induced in the stainless steel plate 30 is “penetration depth (δ = 5030 × √ (ρ / μf); ρ is resistivity, μ is relative permeability, and f is current frequency)” near the surface. If the stainless steel plate 30 is made thinner than the penetration depth, a leakage magnetic flux is generated and the heat generation efficiency is lowered. Therefore, it is preferable to make the stainless steel plate 30 thicker than the penetration depth even when the power that can be supplied to the heating coil 20 during operation can be sufficiently increased without performing preheating. Based on the above equation, the penetration depth (δ) decreases as the frequency of the high-frequency current increases, the resistivity of the stainless steel plate 30 decreases, or the relative magnetic permeability of the stainless steel plate 30 increases. Therefore, by using a high-frequency power source having a high frequency, or using a stainless plate 30 having a high resistivity or a low relative permeability, the penetration depth is reduced and the stainless plate 30 is thinned to perform preheating. Without this, the surface temperature of the stainless steel plate 30 can be raised more quickly.

  In the above embodiments and examples, the manual drying device provided with the IH heater according to the present invention has been described so far, but this IH heater can also be used as other hot air generating devices such as a heating device and a drying device. It can be used similarly. The present invention should not be construed as being limited to the embodiments and examples, but is defined by the appended claims, and variations and modifications apparent to those skilled in the art can be made within the spirit and scope of the present invention. It should be understood that it is included in the present invention without departing from the invention.

1: hand dryer, 2: housing, 3: high-pressure air generator (blower), 4: induction heater (IH heater), 5: control circuit, 6: air inlet, 7: outlet (spout nozzle), 8 : Duct, 9: manual insertion space, 10: outer frame, 12: opening, 14: heater cell, 16: wiring board, 17: wiring terminal, 18: external terminal, 20: heating coil (induction coil), 22: terminal , 23: substrate, 24: metal thin film (conductive layer), 25: polypropylene resin film, 26: glass epoxy resin film, 27: through-hole, 28: terminal, 30: metal plate (object to be heated), 31: IGBT element 32: FWD element, 33: gate control signal, 34: power supply, 36: rectifier circuit, 38: metal tube (heated body), 40: flow path, 42: insulating coating conductive wire, 44: support, 50: hollow Metal tube (object to be heated), 52: flat surface, 5 : Through fixture 55: fixing means, 56: spacer, 60: metal tube (hollow conductor), 64: magnetic shield plate

Claims (20)

An induction coil made of a conductive material;
At least one heated body disposed adjacent to the induction coil;
A power source for supplying a high-frequency current to the induction coil to heat the object to be heated;
An outer frame forming at least one flow path between the heated body;
A blower for forming an air flow in the flow path,
A hot air generator, wherein the air in the flow path is heated by the object to be heated.   The hot air generator according to claim 1, wherein the heated body includes a pair of metal plates that sandwich the induction coil, and extends substantially in parallel along the flow path.   The hot air generator according to claim 2, wherein the induction coil includes a conductive layer patterned on a substrate.   2. The hot air according to claim 1, wherein the induction coil includes an insulating film conductive wire wound around a central axis of the heated object between a pair of adjacent heated objects. Generator. A pair of adjacent to-be-heated bodies are connected via struts,
The hot air generator according to claim 1, wherein the induction coil includes an insulating coating conductive wire wound around the support column.   The hot air generator according to claim 5, wherein the support column is made of a non-magnetic material.   The hot air generator according to claim 1, wherein the object to be heated is formed in a cylindrical shape so as to surround the induction coil. An induction coil made of a conductive material;
At least one hollow object to be heated, which is disposed adjacent to the induction coil and has a flow path therein;
A power source for supplying a high-frequency current to the induction coil to heat the object to be heated;
A blower for forming an air flow in the flow path,
A hot air generator, wherein the air in the flow path is heated by the object to be heated. The heated body has at least one flat outer surface extending substantially parallel along the flow path;
9. The hot air generation according to claim 8, wherein the induction coil includes a support column extending substantially perpendicularly to the outer surface of the heated body, and an insulating film conductive wire wound around the support column. apparatus.   The hot air generator according to claim 9, further comprising a through fixture extending through the support column.   The hot air generator according to claim 8, wherein the heated body has an inner surface extending substantially parallel to the flow path. The heated body has an outer surface extending substantially parallel along the flow path;
The hot air generator according to claim 8, wherein the induction coil is formed so as to wind around the outer surface of the body to be heated. Having at least two sets of the heated object and the induction coil adjacent to each other;
The hot air generator according to claim 12, wherein winding directions of the induction coil wound around the outer surface of the heated body are different from each other.   The hot air generator according to claim 12, further comprising a hollow conductor disposed adjacent to and surrounding the induction coil.   The hot air generator according to claim 1 or 8, wherein the heated body has irregularities in a cross section in a direction in which a surface constituting the flow path is substantially perpendicular to the flow path.   The hot air generator according to claim 1 or 8, wherein the heated body is made of a metal having magnetism. The hot air generator according to claim 1 or 8,
A housing having an intake port for taking in outside air and a jet port for jetting the airflow heated by the warm air generator to the outside;
The air dryer and the jet port communicate with each other through the flow path.   The hand drying apparatus according to claim 17, wherein the induction coil and the heated object are disposed between the blower and the jet outlet.   The hand drying apparatus according to claim 18, wherein the induction coil and the heated body are disposed adjacent to the ejection port.   The hand dryer according to claim 18, wherein a magnetic shield member is provided around the induction coil.

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