JP2679277B2 - Induction heating iron - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an induction heating iron used in ordinary households.

2. Description of the Related Art FIG. 4 is a circuit diagram of an induction heating iron according to the related art. In FIG. 4, 1 is an iron body, 2
Is an ironing board. Ironing board 2 is ironing part 3
And the placing section 4. The heating coil 9 is mounted on the mounting portion 4.
Is provided so that the iron body 1 can be placed and heated before the ironing work or when the clothes are separated during the ironing work. The ironing part 3 is provided with a heating coil 5, a heating coil 6, a heating coil 7 and a heating coil 8 for induction heating the iron body 1 during ironing work and compensating for the heat taken away by the ironing work.

The operation of the conventional induction heating iron having the above structure will be described. The user first of all, the iron body 1
Is placed on the heating coil 9 of the placing unit 4 and heated to a temperature suitable for ironing. When the temperature of the iron body 1 reaches a predetermined temperature, clothes or the like to be ironed are spread on the ironing unit 3, and the ironing unit 1 is used to perform ironing work on the clothes. During the ironing work, heating is performed by the heating coils 5, 6, 7, and 8. That is, if the iron body 1 is located on the heating coil 5, induction heating of the iron body 1 is performed by the heating coil 5, and if the iron body 1 is located on the heating coil 7, the iron body 1 is heated by the heating coil 7. Induction heating is performed. When the clothes are separated or the clothes are exchanged during the ironing work, the user returns the iron body 1 to the placing portion 4 and performs the operation.

With the above operation, sufficient heating power is supplied to the iron body while being cordless, so ironing can be performed using abundant steam.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, in such a conventional induction heating iron, when trying to iron clothes with metal accessories such as metal buttons and chucks, the metal accessories are heated. There is a risk that the coils 5, 6, 7, 8 are heated and their temperatures rise and the user is burned.

The present invention has been made in view of such problems, even when ironing clothes with small metal items,
It is an object of the present invention to provide a safe induction heating iron that can prevent burns.

Means for Solving the Problems Means for achieving the above object comprises an iron body and an ironing board, wherein the ironing board has a heating coil for induction heating the iron body, and a mounting portion for mounting the iron body, Depending on the control circuit that controls the energization of the heating coil, the load detection circuit that outputs a signal to the control circuit when the iron body is placed on the heating coil, and the ratio of the input current of the device and the high-frequency current that flows in the heating coil. Determined,
A metal small object detection circuit for outputting a signal to the control circuit, wherein the control circuit stops energization of the heating coil by an output signal from the metal small object detection circuit when the iron body is placed on the placing portion. belongs to.

The working metal accessory detection circuit detects when a metal accessory such as a metal button or chuck is located on the heating coil when the iron body is placed on the placing part, and sends a metal accessory signal to the control circuit. . Upon receipt of this signal, the control circuit stops the heating coil current. As described above, it is possible to provide a highly safe induction heating iron that can prevent the heating of small metal objects and prevent the user from being burned.

Embodiment FIG. 1 is a block diagram of an induction heating iron according to an embodiment of the present invention. In FIG. 1, 21 is an iron body, and 22 is an ironing board. The ironing board 22 has a heating coil 33 for inductively heating the iron body 21 during ironing work, and a placing part 37 made of a ceramic plate for placing the iron body 21 before the ironing work or between the ironing works. However, the placing portion 37 is provided with an elliptical heating coil 35. The heating coils 33 and 35 are each inverter 10
High frequency current is supplied from 0 ・ 101 to generate high frequency magnetic field,
The iron body 21 is induction heated when the iron body 21 approaches. The input current detection circuit 43 detects the input current of the device, that is, the input power, and transmits this information to the small metal detection circuit 47 or the load detection circuit 49. The heating coil current detection circuit 44 detects the high frequency current flowing through the heating coil 33, and also transmits this information to the small metal detection circuit 47 or the load detection circuit 49. The metal small object detection circuit 47 uses the ratio of the size of the high frequency current and the size of the input current to detect when a metal small object load of a certain size such as a metal button or a chuck is placed on the heating coil 33. Is detected and a small metal signal is output to the control circuit 51. Similarly, the load detection circuit 49 detects that the iron body 21 is located above the heating coil 33 from the ratio between the magnitude of the high frequency current and the magnitude of the input current, and outputs this information to the control circuit 51. The reed switch 42 responds to the magnet 102 of the iron main body 21 when the iron main body 21 is positioned on the placing portion 37 to turn on, and transmits this information to the control circuit 51. The control circuit 51, based on the above-mentioned information, inverters 100 and 1
Control 01 as follows. That is, while the iron body 21 is placed on the placing portion 37, that is, the reed switch 42.
When a metal small object signal is input from the metal small object detection circuit 47 in a state where is turned on, the operation of the inverter 100 is stopped and the supply current to the heating coil 33 is stopped.

FIG. 2 is a specific circuit example showing the block diagram shown in FIG. In the figure, 21 is an iron body, and 22 is an ironing board. The ironing board 22 has a DC power supply 27 and inverters 100 and 101 connected to the DC power supply 27. The inverter 100 includes a series circuit of switching elements 28 and 29, a diode 30 connected in antiparallel between the collector and emitter of the switching element 28, a diode 31 connected in antiparallel between the collector and emitter of the switching element 29, and a resonance capacitor 39. It is composed by. Further, the inverter 101 is a series circuit of switching elements 32 and 38 and a switching element.
Diodes connected in anti-parallel between 32 collector-emitters
34, a diode 40 connected in antiparallel between the collector and emitter of the switching element 38, and a resonance capacitor 41. The output of the inverter 100 is supplied to the heating coil 33, which is provided below the ironing section 36 and induction-heats the iron body during the ironing operation, and the output of the inverter 101.
Is provided in the placing portion 37 and is connected to the heating coil 35 for inductively heating the iron body when the iron body is placed. The input current detection circuit 43 is for detecting the input current of the device.
It is composed of a load resistor 53, a rectifier 54, a capacitor 55 and a resistor 56 for peak-holding its output. The heating coil current detection circuit 44 detects the current of the heating coil 33. In this embodiment, the heating coil current detection circuit 44 includes a current transformer 57, a load resistor 58, a rectifier 59, and a capacitor 60 and a resistor 61 for peak-holding its output. Has been done.
This output is connected to the series circuit of resistors 45 and 46, divided and connected to the comparator 48. Small metal detection circuit
47 is an input current detection circuit composed of the comparator 48
The output of 43 is compared with the partial pressure output to detect that a metal accessory such as a metal button / chuck is placed on the heating coil 33 and output a metal accessory signal to the control circuit 51. Is. The load detection circuit 49 is composed of a comparator 50, and compares the output of the input current detection circuit 43 with the output of the heating coil current detection circuit 44 to determine that the iron body 21 is placed on the heating coil 33. It detects and outputs a signal to the control circuit 51.

FIG. 3 is a small metal detection circuit shown in FIGS. 1 and 2.
47 shows the operating characteristics of the load detection circuit 49 and the load detection circuit 49. In FIG. 3, a is in an unloaded state, a is when the metal button is placed on the heating coil 32 and the like, and w is when the iron body 21 is placed 6 cm away from the center of the heating coil 32. D is the input current I of the device when the iron body 21 is placed on the center of the heating coil 32.
₆ is a graph showing the relationship between _in and the heating coil current I ₁ .
That is, in the circuit of this embodiment, when a load is placed on the heating coil 33, the ratio of the heating coil current to the input current changes depending on the size of the load or the position of the load. When is small, it is difficult to heat and the input current with respect to the heating coil current is small. Similarly, when the position of the load is displaced, the greater the degree of displacement, the more difficult it is to heat, so the input current with respect to the heating coil current becomes small. A broken line a represents a high-low boundary line of the output of the small metal detection circuit 47, and a broken line b represents a high-low boundary line of the output of the load detection circuit 49. That is, the small metal detection circuit 47
Outputs high in the area on the right of the broken line a, outputs low in the area on the left of the broken line a, and the load detection circuit 49 outputs high on the right side of the broken line b and low on the left side. . Therefore, the iron body 21 is placed on the heating coil 32.
If there is, the output of the load detection circuit 49 becomes high,
The small metal detection circuit 47 can output a high signal when there is a small metal object.

The operation of the above configuration will be described. First, the user
The iron body 21 is placed on the placing part 37 of the ironing board 22. Then, the reed switch 42 detects this and transmits this information to the control circuit 51. The control circuit 51 drives the inverter 101 to heat the iron body 21. Iron body 21 is about Celsius
When the temperature reaches 200 degrees, the control circuit 51 detects it. Then, the control circuit 51 checks the output of the small metal detection circuit 47 when the iron body 21 is placed on the placing portion 37. When the heating coil 33 does not have a metal accessory such as a metal button, the output of the metal accessory detection circuit 47 is low. In this case,
Next, when the user places the iron body 21 on the heating coil 33, the output of the load detection circuit 49 becomes high, and the control circuit 51 supplies a high-frequency current to the heating coil 33 to cause the iron body 21 to be ironed during the ironing work. Induction heating. In this case, if the iron body 21 is not located above the heating coil 32,
The output of the load detection circuit 49 becomes low, and the supply of the high frequency current to the heating coil 33 is stopped for a certain period of time. After the elapse of this fixed time, the control circuit 51 checks the output of the load detection circuit 49 and, if it is high, supplies a high frequency current to the heating coil 33 to induction heat the iron body 21. As a result, heat that escapes from the iron main body 21 can be supplied during ironing work, so that high-quality ironing can be performed. By repeating the above operation, the iron body 21 is induction-heated even during the ironing work. Moreover, when the iron body 21 is located in a place other than the heating coil 33, the supply of the high frequency current can be stopped by the action of the load detection circuit 49, so that unnecessary radiation and power loss can be suppressed.

Next, a case will be described in which clothes with metal accessories such as metal buttons are placed on the heating coil 33 of the ironing section 36 and ironing is performed. Iron body
When 21 is placed on the placing portion 37 by the user, the reed switch 42 is turned on and the control circuit 51 operates the inverter 100. In this case, when a metal accessory attached to clothes or the like is placed on the heating coil 33, the metal accessory detection circuit 47 outputs a high metal accessory signal. Therefore, the control circuit 51 detects that the small metal item is placed on the heating coil 33 by the user, and the iron body 21 by the heating coil 33 thereafter is detected.
To stop induction heating. That is, in this case, the iron body 21 is induction-heated by induction heating only when the user places the iron body 21 on the placing portion 37. Therefore, according to this embodiment, there is no risk of the user being burned.

In the present embodiment, the reed switch 42 is provided on the ironing board 22 side to prevent the iron body 21 from being mistakenly detected as a metal accessory by the metal accessory detection circuit 47, and heating by the heating coil 35 is completed. Immediately after the detection of small metal objects, it may be possible to use the fact that the impedance of the heating coil 35 changes depending on whether the iron body 21 is present or absent. May be detected on the placing portion 37. In short, it suffices if the control circuit 51 detects a small metal item while the iron body 21 is in the placing portion 37. Further, in the present embodiment, when a small metal item is detected, the user is not notified only by stopping the induction heating during the ironing work, but the user is notified of the presence of the small metal item by, for example, ringing a bell. It may be configured to notify. Furthermore, in the present embodiment, the number of heating coils for heating the iron main body 21 during the ironing work is only one of the heating coils 33.
When the output of 49 is low, the heating coils may be switched one after another. By increasing the number of heating coils, the iron body is sufficiently heated during ironing work, so that the temperature of the iron body is always kept high, and better ironing is possible. In this case, all the heating coils in the ironing part 36 may be stopped when a small metal item is detected by one heating coil, or only the heating coil in which the presence of a small metal item is detected. You may stop it. Further, in the present embodiment, the two-stone resonance type half-bridge inverter is used, but the same effect can be obtained by applying it to other inverter types, and the number of the inverters is set to one, and the position of the iron main body 21 is adjusted. The heating coil of the placing section and the ironing section may be switched according to the above.

EFFECTS OF THE INVENTION As is clear from the above embodiments, the induction heating iron according to the present invention comprises an iron body and an ironing board, and the ironing board includes at least one heating coil for inductively heating the iron body during ironing work. , A mounting portion for mounting the iron body, and a small metal detection circuit and a control circuit, the small metal detection circuit is a control circuit when a load of a certain size or more is located on the heating coil. By outputting a metal accessory signal, the control circuit stops the electric current of the heating coil when the iron body receives the metal accessory signal from the metal accessory detection circuit in a state in which the iron body is in the placement section. It is possible to prevent small metal objects such as metal buttons and chucks from being heated by induction, and to prevent the user from being burned.

[Brief description of the drawings]

FIG. 1 is a block diagram of an induction heating iron according to an embodiment of the present invention, FIG. 2 is a concrete circuit diagram thereof, FIG. 3 is an operation characteristic diagram of the metal small object detection circuit and load detection circuit, and FIG. It is a top view of the induction heating type iron in a prior art. 21 …… Iron body, 36 …… Ironing board, 33 …… Heating coil, 37 …… Mounting section, 47 …… Metal accessory detection circuit, 51 ……
Control circuit.

Claims (1)

(57) [Claims] 1. An iron body and an ironing board, wherein the ironing board has a heating coil for inductively heating the iron body, a mounting portion for mounting the iron body, a control circuit for controlling energization of the heating coil, and heating. A load detection circuit that outputs a signal to the control circuit when the iron body is placed on the coil, and a metal that outputs a signal to the control circuit, which is determined by the ratio between the input current of the device and the high-frequency current flowing in the heating coil. An induction heating iron, comprising: an accessory detection circuit, wherein the control circuit stops the energization of the heating coil in response to an output signal from the metal accessory detection circuit when the iron body is placed on the placing portion.