JP2650718B2 - Induction heating iron - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an induction heating type iron which is a type of cordless iron.

2. Description of the Related Art Conventionally, this type of iron is configured as shown in FIG. A heating coil 4 is arranged on the back side of an ironing table 3 composed of a cushion 1 and a skin cloth 2 covering the surface thereof. A commercial power supply 6 is connected to an inverter 7 in a series circuit of the heating coil 4 and the resonance capacitor 5. A high-frequency signal whose frequency has been converted by is applied. The inverter 7 is of a half-bridge type, and includes a rectifying unit 8 for full-wave rectifying a commercial power supply voltage to convert it to a DC voltage, and first and second transistors Q1 connected in series between outputs of the rectifying unit 8. , Q2, and a drive circuit 9 that turns on the first and second transistors Q1 and Q2 alternately at a predetermined cycle when the iron body 11 is in a heating range near the heating coil 4. Ironing work is to be ironed such as clothes and handkerchiefs
This is performed by laying 10 on the ironing table 3 and sliding the iron body 11 on it.

SUMMARY OF THE INVENTION In such a conventional configuration, the iron body 11 is heated by induction heating due to a change in the alternating magnetic flux generated from the heating coil 4, so that the iron body 11 is directly supplied with power. This eliminates the need for a power cord, making ironing easier. However, even when the iron body 11 is left on the ironing table 3 during ironing, the iron body 11 is continuously heated by dielectric heating. When the temperature of the iron body 11 rises to about 200 ° C., the iron body 11 is damaged. Ironing material 10, skin cloth 2, cushion 1 burnt,
If left unattended for a long time, there is a risk of fire.

SUMMARY OF THE INVENTION An object of the present invention is to provide an induction heating type iron that can prevent an increase in temperature of an iron body when the iron body is left on an iron table.

Means for Solving the Problems The induction heating type iron according to claim 1, wherein a heating coil attached to the side of the ironing table is driven by an inverter, and the iron body mounted on the ironing table is induction heated. An impedance detecting means for detecting the impedance of the heating coil, and reading an output of the impedance detecting means to detect that the impedance of the heating coil does not change for a specified time, thereby reducing the input power of the heating coil. A control means for controlling the inverter is provided.

The induction heating iron according to claim 2, wherein the heating coil attached to the iron table side heats the iron body mounted on the iron table by induction, and detects temperature of the heating coil, and temperature detection means. Control means for reading the output of the means, detecting that the detected temperature has reached the specified temperature, and controlling the input power to the heating coil in a direction to reduce it.

In the induction heating type iron according to the third aspect, a heating coil mounted on the side of the ironing table is driven by an inverter to inductively heat the iron body mounted on the ironing table and to detect a temperature of the inverter. Means, and control means for reading the output of the temperature detecting means, detecting that the detected temperature has reached the specified temperature, and controlling the inverter in a direction to reduce the input power only to the heating coil. Features.

According to the configuration of the first aspect, when the iron body moves on the iron table, the distance between the heating coil and the iron body changes, and the impedance of the heating coil changes with time. When the iron body is left on the ironing table, the impedance of the heating coil does not change over time. If the control means detects that the impedance of the heating coil detected by the impedance detection means does not change for a specified time, the control means determines that the iron body is left unattended, and the input power to the heating coil is determined. To reduce.

According to the configuration of the second aspect, when the iron body is moving on the ironing table, the heating coil is energized only when the iron body is within a heatable range near the heating coil by the action of the drive circuit. Therefore, when the iron body is left within the range where heating is possible, a high-frequency current flows continuously through the heating coil, and the heating coil generates heat above a specified temperature. When the control unit detects that the temperature of the heating coil detected by the temperature detection unit has reached the specified temperature, the control unit determines that the iron body is left unattended, and reduces the input power to the heating coil. Instruct.

According to the configuration of the third aspect, when the iron main body is moving on the ironing table, the heating coil is energized only when the iron main body is within a heatable range near the heating coil by the action of the drive circuit. Therefore, when the iron main body is left within the heatable range, a high-frequency current continuously flows through the heating coil, and the inverter that drives the heating coil generates heat above a specified temperature. When the control unit detects that the temperature of the inverter detected by the temperature detection unit has reached the specified temperature, the control unit determines that the iron body is left unattended, and reduces the input power to the heating coil. To instruct.

Embodiments Embodiments of the present invention will be described below with reference to FIGS. In addition, the same reference numerals are given to the elements which perform the same operation in FIG.

FIG. 1 shows an induction heating type iron according to claim 1, which differs from FIG. 6 in that an impedance detecting means 12 and a control means 13 are added. Heating coil 4
Impedance detection means 12 for detecting the impedance of
A current transformer 14 in which a primary winding is interposed in series with a circuit of a heating coil 4 and a resonance capacitor 5;
And a capacitor 17 for rectifying and smoothing the terminal voltage generated in the load resistor 15 connected to the secondary winding of the heating coil 4. output voltage V ₁ is changed. And the control means 13 the analog-to-digital converter 18 for digitally converting the output voltage V ₁ of the said period of connexion digital output value D ₁ read repeatedly digital output value D ₁ of the analog-to-digital converter 18 does not change continuously And a determination unit 19 for detecting whether or not the length of the digital output value D ₁ has reached the specified time T. The determination unit 19 determines that the length of the period during which the digital output value D ₁ does not change exceeds the specified time T. Output voltage V ₂
Is inverted to “L” level. Here, during the period when the output voltage V ₂ is at the “H” level, the drive circuit 9 of the inverter 7 turns on the transistors Q 1 and Q 2 alternately, and the output voltage V ₂
Is configured to maintain the transistor Q1 in the off state when the signal is inverted to the “L” level.

FIG. 2A shows a current waveform of the heating coil 4. Times of Day
Until t1, the user puts the iron body 11 on the ironing table 3
, The impedance of the heating coil 4 changes in accordance with the change in the position of the iron body 11, and the current i flowing through the heating coil 4 changes with time. When the inverter 7 is operated near the resonance frequency determined by the resonance capacitor 5 and the heating coil 4, the current i increases as the iron body 11 moves away from the center of the heating coil 4. When the current i varies with time as shown in FIG. 2 (a), the power voltages V ₁ and the digital output value D ₁ also FIG. 2 (b), varies as shown in (c).

Assuming that the user leaves the iron body 11 on the heating coil 4 at time t1, the iron body 11
When the positional relationship between 11 and the heating coil 4 becomes constant, the impedance of the heating coil 4 becomes constant, so that the current i becomes constant. The While connexion output voltage V ₁ and the digital output value D ₁ is also constant. The determination unit 19 determines the digital output value D ₁ as described above.
Monitors the length of a certain period, and when this length reaches a specified time T, as shown in FIG.
V ₂ is inverted to “L” level, and the driving of the heating coil 4 is stopped.

With this configuration, if the specified time T is set to one minute, the iron body 11 is left on the ironing table 3 and the heating is automatically stopped in one minute, and the ironing object 10, the skin cloth 2. A fire accident caused by burning of the cushion 1 can be avoided, and safety is improved.

FIG. 3 shows another embodiment of the present invention.
In the embodiment shown in FIG. 1, a change in the current i flowing through the heating coil 4 and the resonance capacitor 5 is detected by the impedance detecting means 12 to detect a change in the impedance of the heating coil 4. However, in the embodiment shown in FIG. Then, a change in the input current Iinv to the inverter 7 is detected by the impedance detecting means 12 to detect a change in the impedance of the heating coil 4, and a control means is provided for controlling that the impedance of the heating coil 4 does not continuously change over a specified time T. When the detection 13 is detected, the control means 13 instructs the inverter 7 to stop driving the heating coil 4. In this embodiment, the drive frequency of the drive circuit 9 during normal ironing operation is set to a voltage limiter so that the terminal voltage of the resonance capacitor 5 becomes constant.
When the iron body 11 moves away from the heating coil 4, the voltage limiter 20 increases the drive frequency of the drive circuit 9 so that the terminal voltage of the resonance capacitor 5 does not exceed a specified value. So
The input current Iinv of the inverter 7 decreases.

In the embodiment shown in FIG.
When 11 is left on the ironing table 3, the specified time T
After that, the driving of the heating coil 4 is stopped, and a fire accident can be avoided.

In each of the embodiments shown in FIGS. 1 and 3 described above, the determination unit 19 detects that the state in which the digital output value D ₁ of the analog-to-digital conversion unit 18 does not change at all continues for a specified time T, and the heating is performed. an example has been described for stopping the driving of the coil 4, the digital is a minute state change of the output value D ₁ is the prescribed time T
In this case, the determination unit 19 detects the continuation of the operation and stops the driving of the heating coil 4, thereby improving reliability against noise and the like.

FIG. 4 shows an induction heating type iron according to claim 2, which is different from FIG. 6 in that a temperature detecting means 21 and a control means 22 are added. The temperature detecting means 21 is arranged at a position near the heating coil 4 so as to detect the temperature of the heating coil 4. Control means 22 detects that the temperature detected by the temperature detecting means 21 rises to a specified temperature Th _1, is configured to continue to hold the switching-transistor Q1, Q2 by the drive circuit 9 in a stopped state.

With such a configuration, the following operation is performed. During normal use of ironing, heating is performed only in the heatable range, so that the high-frequency current flowing through the heating coil 4 is intermittent, and the heat of the heating coil 4 is appropriately radiated, and the temperature is regulated. Although the temperature does not rise to Th ₁ , when the iron body 1 is left in the heating range of the iron table 3 and the high-frequency current flowing through the heating coil 4 becomes continuous,
Temperature of the heating coil 4 defines control means 22 which detects this reaches the temperature Th ₁ is to avoid fire stops the driving of the heating coil 4.

FIG. 5 shows another embodiment of the present invention.
In FIG. 4, the temperature of the heating coil 4 is directly
5, the drive circuit 9 is controlled via the control means 22. In the embodiment shown in FIG. 5, the temperature of the inverter 7 is detected by the temperature detection means 21, and the drive circuit 9 is controlled via the control means 22. It is configured to control.

Heating coil 4 when using normal ironing
Since the value of the high-frequency current flowing through the
Of the transistors Q1, Q2 of heat is moderately dissipated, the temperature is not raised to the specified temperature Th ₂ set in the control unit 22, the heating coil 4 iron main body 11 is left on the ironing table 3 frequency flowing through the current, i.e. the current flowing through the transistors Q1, Q2 does not change, the temperature of the transistors Q1, Q2 has reached the specified temperature Th _2, the control unit 22 detects the stop switching-transistors Q1, Q2 so Thus, the driving of the heating coil 4 is stopped to avoid a fire accident.

Effects of the Invention As described above, according to the configuration described in each claim, the impedance of the heating coil is detected by the impedance detecting means, or the temperature of the heating coil or the inverter is detected by the temperature detecting means, and the impedance and the temperature are detected. In order to control the inverter in the direction to reduce the input power to the heating coil by judging the abnormal state by the control means, when the iron body is left on the iron table, the heating coil is automatically energized. Is stopped to prevent the temperature of the iron main body from rising, thereby avoiding a situation that may lead to a fire accident.

[Brief description of the drawings]

FIG. 1 is a block diagram of a first embodiment of an induction heating iron according to claim 1, FIG. 2 is a waveform diagram of a main part of the apparatus, FIG. 3 is a block diagram of a second embodiment, FIG. FIG. 4 is a structural view of an embodiment of the induction heating type iron according to claim 2, and FIG. 5 is claim 3.
And FIG. 6 is a configuration diagram of a conventional induction heating type iron. 3 ... iron table, 4 ... heating coil, 7 ... inverter, 11 ... iron body, 12 ... impedance detecting means, 13 ... control means, 21 ... temperature detecting means, 22 ...
... Control means.

Claims (3)

(57) [Claims] 1. An induction heating type iron for inductively heating an iron body mounted on an iron table by driving a heating coil mounted on an iron table side by an inverter, and detecting impedance of the heating coil. Means for controlling the inverter to reduce or stop the input power to the heating coil when the impedance of the heating coil does not change in a predetermined time by the output of the impedance detecting means. Heated iron. 2. An induction heating type iron for inductively heating an iron body mounted on the ironing table by driving a heating coil mounted on the ironing table side by an inverter, and detecting a temperature of the heating coil. And a control means for controlling the inverter to reduce or stop the input power to the heating coil until the detected temperature is equal to or higher than a predetermined temperature by the output of the temperature detection means. Induction heating iron. 3. An induction heating type iron for driving a heating coil attached to an ironing table side by an inverter and inductively heating an iron body mounted on the ironing table, a temperature detecting means for detecting a temperature of the inverter. An induction heating iron having a control means for controlling the inverter to reduce or stop the input power to only the heating coil when the detected temperature is equal to or higher than a predetermined temperature by the output of the temperature detection means.