JPS6158699A - Safety apparatus of electric iron - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention provides a system for stopping the heater when the electric iron is in a horizontally stopped state or in a free standing state in which the iron base is separated from the object to be ironed such as cloth for a certain allowable time. This invention relates to a safety device for an electric iron that cuts off electricity.

[Technical Background of the Invention and Its Problems] Electric irons generally incorporate a temperature control device to maintain a substantially constant temperature of the iron base that directly contacts the fabric being ironed. In such a temperature control device, a switching circuit such as a relay is inserted between, for example, a 100-volt AC power source and a heater attached to an iron base, and the temperature of the iron base is transferred to the iron base heated by the heater. A temperature detection element such as a mister is installed to detect the temperature.
A comparator circuit compares the temperature detected by this temperature detection element and the set temperature, etc., and when the detected temperature rises above the set humidity, a circuit cutoff signal is sent to the switching circuit, and the detected temperature falls below the set temperature. and sends a circuit conduction signal to the switching circuit. In this way, the temperature of the iron base is maintained approximately at the set temperature.

However, if the user leaves the electric iron in a horizontal ironing position (for example, to hear a telephone ringing or a visitor arrive, etc.), or even if the electric iron is left standing on its own as shown in Figure 4, There is a fear that a fire may occur if an electric iron falls over due to some reason such as an earthquake.

In consideration of such cases, some electric irons have
Some iron handles are equipped with a switch mechanism in the grip section, so that the temperature control device operates only when the iron handle is being gripped.

However, in an electric iron with a switch mechanism installed in the grip of the iron handle, as shown in Figure 4, the power to the heater is immediately cut off as soon as you take your hand off the iron handle. Even when the ironing board is left on its own and the cloth on the ironing board is being repaired or turned inside out, the heater is shut off. Therefore, when the iron handle is grasped to resume ironing, there is a concern that the temperature of the iron base frequently falls below the set temperature. As a result, there was a risk that a good iron finish could not be obtained.

[Object of the Invention] The present invention has been made based on the above-mentioned circumstances, and its purpose is to keep the electric iron in a constant horizontal ironing state by providing a state detection switch with a simple structure. To provide a safety device for an electric iron that can further improve the safety of an electric iron at a low cost by cutting off electricity to a heater when it is left unattended for more than a certain period of time or left in a free-standing state for more than a certain period of time. There is a particular thing.

[Summary of the Invention] The safety device for the electric iron of the present invention is designed to prevent the electric iron from being in a horizontal stop state, a self-supporting state indicating that the iron base is away from the object to be ironed, and a horizontal reciprocating state during ironing. a state detection switch that detects the horizontal stop state of the electric iron; a first timer circuit that measures the duration of time during which the state detection switch detects the horizontal stop state of the electric iron; A second timer circuit is provided to measure the duration of time when the power source is connected to the power supply when the duration timed by the first and second timer circuits reaches a predetermined horizontal stop permissible time or self-sustaining permissible time, respectively. A circuit cutoff signal is sent to a switching circuit inserted between the heater and the heater.

[Embodiments of the invention] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a circuit diagram showing a safety device for an electric iron according to an embodiment. Reference numeral 1 in the figure is an AC power supply that supplies 100 volt AC power to this electric iron through an outlet or plug, for example, and a heater 3 cast in an iron base 2 shown in FIG. It is connected via contacts 5 of a relay 4 as a circuit.

In the figure, 6 is a voltage terminal that supplies DC drive voltage Vc to each electronic component that constitutes this circuit, and a comparison circuit 7 for temperature control of the iron base 2 is connected between this voltage terminal 6 and the ground. . A set temperature Ts and a detected temperature T from a temperature setting variable resistor 8 and a thermistor 9 as a temperature detecting element attached to the iron base 2 are inputted to the comparison circuit 7. The output terminal of the comparison circuit 7 is connected to the base of a transistor 11 connected between the voltage terminal 6 and ground via the drive coil 10 of the relay 4.

Further, a state detection switch 13 is connected between the power supply terminal 6 and the ground via a resistor 12.

This state detection switch 13 is configured as shown in FIG. 2, for example. That is, one electrode 14 is attached to the bottom of a bottomed cylindrical case 15 made of a conductive material, and the other electrode 16 is attached by passing through a through hole bored at the opposite end of the case 15. It is being Note that an insulating material 17 is embedded between the electrode 16 and the through hole. Inside the cylindrical case 15, mercury 18 is sealed. This state detection switch 13 is not shown in FIG.
As shown in the figure, an electrode 74 is fixed at a slight inclination so as to be positioned on the lower side as shown in the figure.

Therefore, if one electric iron is stopped horizontally, such as when ironing, as shown in Figure 3,
Since the mercury 18 sealed in the case 15 is located on the electrode 14 side, the space between the electrodes 14 and 16 is open. on the other hand,
As shown in FIG. 4, when the iron base 2 is separated from the object to be ironed and one electric iron stands on its own, the mercury 18 sealed in the case 15 rolls in the opposite direction and the electrode 1
Contact 6. As a result, conduction occurs between the electrodes 14 and 16. Furthermore, if you come while the ironing operation is in progress,
Since one electric iron performs reciprocating motion while maintaining the horizontal state shown in FIG. 3, the mercury 18 inside the case 15 rolls back and forth. As a result, this state detection switch 13 repeats the conduction and cutoff states.

In FIG. 1, the electrode 14 of the state detection switch 13 is
It is connected to the base of a transistor 23 which is connected via a resistor 22 between the voltage terminal 6 and ground. Further, a first timer circuit 24 and a second timer circuit 25 are connected in series between the voltage terminal 6 and the ground.
The reset terminal of the second timer circuit 25 is connected to the collector of the transistor 23, and the reset terminal of the second timer circuit 25 is connected to the electrode 14 of the state detection switch 13.

The first timer circuit 24 is formed of, for example, a monostable circuit, and when the L-level signal 1- signal is input to the reset terminal R, the horizontal stop permissible time TI ( After the elapsed time, an H level signal is output from the output terminal.Please note that the allowable horizontal stop time T
When the signal level at the reset terminal changes to H level before the end of H time measurement, the duration time measured before the change is cleared, and when the reset terminal page goes to L level again, the horizontal stop permissible time TI (time measurement starts again). Similarly, in the second timer circuit 25, when an L level signal is input to the reset terminal k, the resistor 26b and capacitor 27
After the self-supporting allowable time Tv determined by the time constant b has elapsed, an H level signal is output from the output terminal. The output terminals of the first and second timer circuits 24, 25 are connected to the voltage terminal 6 via diodes 28, 29 and resistors 30 for backflow prevention, respectively. ! 1 to 1 connected through a resistor 31 between
It is connected to the base of transistor 32. The collector of this transistor 32 is connected to the base of the transistor 11 similarly to the output terminal of the comparison circuit 7.

Note that base resistors 33, 34, . ．． 35 is connected, and a diode 36 is inserted between both terminals of the drive coil 10 of the relay 4.

In addition, the horizontal stop permissible time TH is the electric iron 1
The allowable time is for keeping the iron 9 in a horizontal position and not moving it, so the time is set so that the cloth will not burn even if one electric iron is left on the cloth to be ironed 1-1. ing. On the other hand, the self-supporting allowable time Tv is the permissible time when the electric iron 19 is freestanding as shown in FIG. The time required,
This is set to the maximum time required to fix or turn the cloth on the ironing board while the electric iron 19 is standing on its own.

With the electric iron safety device configured in this way, when the power is turned on, the temperature T of the iron base 2 has not reached the set temperature Ts set by the variable resistor 8, so the thermistor 9 The resistance value is large, and a 1H level output signal is applied from the comparator circuit 7 to the base of the transistor 11. On the other hand, when the power is turned on, the electric iron 19 is generally in an independent state as shown in FIG. 4, so the state detection switch 13 is in a conductive state. Therefore, since the potential of the electrode 14 is at the ground level, the reset terminal R of the second timer circuit 25 goes to L level at the same time as the power is turned on, and starts counting the self-sustainable time Tv. In addition, since the transistor 23 is not conductive, the reset terminal of the first timer circuit 24 is at the "]" level and does not start counting the horizontal stop permissible time TRI. 1st and 2nd
Since the output signals of timer circuits 24 and 25 are at L level, transistor 32 is not conductive. Therefore, since the transistor 11 is made conductive by the H level signal from the comparison circuit 7, a drive current flows through the drive coil 10 of the relay 4 and the contact 5 is closed.

When the contact 5 is closed, current flows from the AC power source 1 to the heater 3, and the iron base 2 is heated.

When the temperature T of the iron base 2 reaches the set temperature Ts,
The resistance value of the thermistor 9 decreases and the output signal of the comparison circuit 7 changes to L level. As a result, the transistor 11 is cut off, so the contact 5 of the relay 10 is opened, and the current supply to the heater 3 is cut off. In this way, the temperature T of the iron base 2 is maintained approximately at the set temperature T8. Note that the self-supporting allowable time Tv is determined by the temperature T of the iron base 2.
is set to a value longer than the time required for the temperature to rise to the set temperature Ts, so the transistor 32
The current supply to the heater 3 will not be cut off due to conduction.

When the temperature T of the iron base 2 rises to the set temperature T8 and the user holds the electric iron 19 horizontally as shown in FIG. 3 in order to iron, the state detection switch 13 is opened. . Therefore, since the potential of the electrode 14 changes to H level, the second timer circuit 25
The reset terminal k changes to H level, and the duration time measured up to now is cleared. Also, 1 - transistor 2
Since the base of 3 changes to I'' level, the transistor 23
becomes conductive, and the reset terminal of the first timer circuit 24 changes to the low level. As a result, the first timer circuit 24 starts counting the allowable horizontal stop time TH.

However, during the ironing operation, the electric iron 19 is repeatedly moved back and forth, so the state detection switch 1
The mercury 18 sealed in the case 15 of No. 3 rolls back and forth. As a result, the state detection switch 13 repeats conduction and disconnection within a single period of time, so that the first and second timer circuits 24
．． 25 is constantly cleared, and the measurement of the horizontal stop permissible time TH or self-sustaining permissible time Tv never ends. Therefore, the transistor 32 is never conductive, so
The transistor 11 that operates the relay 4 is ON/OFF controlled only by the output signal of the comparator circuit 7. In this way, during normal ironing work, the first and second
Since the timer circuits 24 and 25 do not operate, the temperature T of the iron base 2 is always maintained at the set temperature Ts by the comparator circuit 7.

Next, for some reason, one electric iron is left in the horizontal ironing state as shown in Figure 3, and when the duration reaches the horizontal stop permissible time TH, the first timer circuit is activated. Since an H level signal is applied from the wind to the base of the transistor 32, this transistor 32 becomes conductive and the base potential of the transistor 11 is forcibly changed to the L level. Therefore, the transistor 11 is cut off regardless of the level of the signal output from the comparator circuit 7. As a result, power supply to the heater 3 is forcibly cut off.

Furthermore, when the electric iron 19 is left standing on its own as shown in FIG. Similarly, the power supply to the heater 3 is forcibly cut off.

In this way, even if the electric iron 19 is left in a horizontal ironing state due to a telephone ringing, a visitor, etc., the heater 3 is automatically shut off after the horizontal stop permissible time TH has elapsed. , can prevent fires and improve safety.

Furthermore, even if the electric iron 19 is left in a free-standing state as shown in FIG. Even if something falls down, there will be no fire, further improving safety.

Furthermore, during normal ironing work, the first and second timer circuits 24 and 25 do not operate, and the iron base 2 is always maintained at the set temperature Ts, so it is possible to obtain a good iron finish. be.

Furthermore, since the state detection switch 13 has a simple structure consisting of a cylindrical case 15 filled with mercury 18 as shown in FIG. The overall manufacturing cost of the electric iron 19 does not increase significantly or its shape increases.

Note that the present invention is not limited to the embodiments described above. In the embodiment, the state detection switch 13 is configured as shown in FIG. 2, but it may also be configured using a microswitch 41 as shown in FIG. That is, the actuator 4 pivotally supported at one end of the microswitch 41
A weight 43 is attached to the tip of 2, and 1 electric iron is attached to the 3rd tip.
It is fixed in the electronic component storage section 21 so that it has the vertical relationship shown in FIG. 5 when it is in the horizontal state shown in the figure. When the microswitch 41 is fixed in this way, the actuator 42 does not touch the operating rod 44 in the horizontal state shown in FIG. 3, and the weight 43 swings during the ironing operation, causing the actuator 4
2 pushes the operating rod 44 from time to time. When the actuator 42 is made to stand on its own as shown in FIG. 4, the actuator 42 continues to push the operating rod 44 due to the gravity of the weight 43. Therefore, since the state detection switch using this microswitch 41 operates in the same way as the state detection switch 13 shown in FIG. 2, it is possible to obtain the same effect as the safety device of the embodiment.

[Effects of the Invention] As explained above, according to the present invention, by providing a state detection switch with a simple configuration, an electric iron can be left in a horizontal ironing state for a certain period of time or longer, or can be left in a free standing state for a certain period of time. If the heater is left unattended for longer than that, the power to the heater will be cut off. Therefore, the electric iron can be made small, lightweight, and inexpensive, and safety can be further improved.

[Brief explanation of drawings]

Fig. 1 is a circuit diagram showing a safety device for an electric iron according to an embodiment of the present invention, Fig. 2 is a sectional view showing a state detection switch used in the safety device, and Fig. 3 is a circuit diagram showing a state detection switch used in the safety device. FIG. 4 is a diagram showing the electric iron in a horizontal state, FIG. 4 is a diagram showing the electric iron in a freestanding state, and FIG. 5 is a front view showing a state detection switch used in another embodiment of the present invention. 1...AC power supply, 2...iron base, 3...
Heater, 4... Relay, 7... Comparison circuit, 8...
Variable resistance, 9...Thermistor, 11, 23.32...
- Transistor, 13... State detection switch, 14.
16... Electrode, 15... Case, 18... Mercury,
19... Electric iron, 21... Electronic parts storage section,
24...First timer circuit, 25...Second timer circuit, 41...Micro switch. Figure 4 Figure 5

Claims (1)

[Claims] A temperature detection element detects the temperature of an iron base heated by a heater connected to a power source via a switching circuit, and the switching circuit is controlled on/off based on the temperature detected by the temperature detection element. In the electric iron that maintains the temperature of the iron base at a set temperature, the electric iron is in a horizontal stopped state, a self-standing state indicating that the iron base is separated from the object to be ironed, and a horizontal reciprocation during ironing. a state detection switch that detects the operating state; and a state detection switch that measures the duration of time during which the state detection switch detects the horizontal stop state of the electric iron, and when this duration reaches a predetermined horizontal stop permissible time. a first timer circuit that sends a circuit cutoff signal to the switching circuit; and a first timer circuit that measures the duration of time during which the state detection switch detects the self-sustaining state of the electric iron; and a second timer circuit that sends a circuit break signal to the switching circuit when the time is reached.