JPH0148796B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an iron having a function of preventing overheating accidents caused by forgetting to turn off the power.

Prior Art A conventional iron with a power-off detection function shuts off the heater when a predetermined time elapses while the iron is left standing.

Problems to be Solved by the Invention Although it is possible to prevent overheating accidents caused by forgetting to turn off the power in the conventional device described above, there is a risk that the following malfunctions may occur. That is, when the temperature control level of the iron base is changed from high temperature to low temperature, a prescribed time period elapses during the waiting time until this low temperature level is reached, and the forgotten-to-cut detection function is activated.

The present invention solves these conventional problems, and provides an iron with a forget-to-turn-off detection function that does not activate the forget-to-turn-off detection function during the waiting time when the temperature setting level is changed from high to low. It is intended to.

Means for Solving the Problems In order to achieve the above object, the present invention stops the time counting operation of the timer section when the temperature control section is OFF, and only counts the time when the temperature control section is ON. However, when this count value reaches a specified value, the heater is shut off. That is, when the cumulative value of the ON time of the temperature control section exceeds a specified time while the iron is in a stationary state, it is determined that the user has forgotten to turn off the power, and the heater is shut off.

Function: While the iron is in use, the usage state detection unit detects the reciprocating movement of the iron and resets the timer circuit, so the timer circuit does not count the specified time. If you forget to turn off the iron and leave it unattended, the timer circuit will not be reset and the ON time will accumulate because there is no reciprocating movement. When this cumulative value reaches a predetermined time, the timer section outputs a signal to the cutoff section to cut off the heater.

Furthermore, when the set temperature is changed from a high temperature to a low temperature, it takes a long time for the temperature to drop to a low temperature level, but since the temperature control section is turned off, the time counting operation of the timer circuit is stopped. Therefore, the power off forgetting detection operation is not performed, and the iron waits until the temperature of the iron reaches the set low temperature level and the temperature control section is turned on, and after reaching the set low temperature level, normal operation is performed.

Embodiment FIG. 1 is a block diagram showing an embodiment of an iron with a power-off detection function according to the present invention. In the figure, reference numeral 1 denotes a usage state detection section, which in this embodiment is composed of a photointerrupter and a ball. Second
The configuration of this usage state detection section 1 is shown in the figure. In FIG. 2, reference numeral 7 denotes a case, and a ball 8 is built into the case, and the ball 8 rolls as the iron reciprocates. 9 is a photointerrupter installed on the case wall, which contains a light emitting diode and a phototransistor. When the ball 8 is on the photointerrupter 9, light emitted from the light emitting diode in the photointerrupter 9 is reflected by the ball 8 and input to the phototransistor in the photointerrupter, and the phototransistor is turned on. When the ball 8 is not on the photointerrupter, the phototransistor is OFF because the light emitted from the light emitting diode is not input to the phototransistor. That is, while using the iron, the ball 8 reciprocates inside the case 7,
Since the light passes over the photointerrupter 9, the phototransistor is repeatedly turned ON and OFF, and when not in use, the phototransistor maintains the ON or OFF state.

Reference numeral 2 denotes a timer section which outputs a signal to the cut-off section 3 when a specified time has elapsed if it is not reset. The cutoff section 3 receives a signal from the timer section 2 and cuts off the circuit of the heater 6 . 4 is a temperature control unit which detects the base temperature of the iron and turns on the heater 6 if it is lower than the set temperature, and turns it off if it is higher to keep the base temperature of the iron constant. 5 is a temperature control section 4
Temperature control unit 4 is turned OFF by the ON/OFF signal detection unit of
The time counting operation of the timer section 2 is stopped during this period.

FIG. 3 is a graph of temperature control with time on the horizontal axis and temperature on the vertical axis. In the figure, t ₁ , t ₃ , t ₅ ,
t ₇・t ₉ is the time when the heater 6 is ON, t ₂・t ₄・
t ₆ , t ₈ , and t ₀ are times during which the heater 6 is turned off.
A is the temperature setting level at high temperature, and B is the temperature setting level at low temperature.

When the temperature setting level of the iron is changed from level A to level B, the time _t8 during which the temperature decreases is a long time because the heat capacity of the iron is large. Here, if T is the specified time set in the timer section 2, it is sufficient to set T> _t8 , but this T
is the time required to cut off the circuit of the heater 6 when the iron is left still, and if it is too long, there is a risk of an accident due to overheating. Therefore, the specified time T is shortened, and the standing time is the specified time T.
If the circuit of the heater 6 is cut off when the level is reached, the timer unit 2 will output a cutoff signal within the waiting time _t8 from the A level to the B level.
Even if the level B is reached, the heater 6 will not turn on.

To deal with such a malfunction, in this embodiment, the time _t8 when the heater 6 is OFF is not counted as the forget-to-turn-off detection time, but only the time when the heater 6 is ON is counted, and the above-mentioned malfunction is detected. This is to eliminate the problem. In other words, in Fig. 3, for example, the movement of the iron is stopped at point K, and the setting level is set to A.
When changing from level to B level, the specified time T
is the cumulative value of the time the heater 6 is on, T= _t7 + _t9 .

If the specified time T is set at such a time, even if the iron is left at rest with the setting level set to A, the power to the heater 6 will be cut off when the time equivalent to (t ₇ + t ₉ ) has elapsed. I will let you do it.

Next, FIG. 4 shows an example of an implementation circuit. V _AC is the AC power supply, 10 is the contact of relay R _L , and when transistor Q ₁ is turned on, current flows to the relay coil.
Turned on. Relay contact 10, relay R _L and transistor Q ₁ constitute interrupting section 3 in FIG.
Reference numeral 11 denotes a thermostat, which constitutes a temperature control section 4 that turns off when the base temperature of the iron is high and turns on when it is low to keep the base temperature of the iron constant. Resistor R ₉ is for voltage drop, D ₁ is a rectifier diode, and C ₃ is a smoothing capacitor, forming a power supply circuit that converts AC power supply voltage to DC voltage.
PD ₁ is a light emitting diode (hereinafter simply referred to as PD ₁ ),
PQ ₁ is a phototransistor (hereinafter referred to as PQ ₁ )
These PD ₁ and PQ ₁ are built into the photointerrupter. When light enters PQ ₁ , PQ ₁ turns ON
However, the collector voltage of PQ ₁ is zero, and when no light enters PQ ₁ , PQ ₁ is OFF, and the collector voltage becomes the DC power supply voltage V _CC .

When using the iron, the ball rolls on PD ₁ and PQ ₁ , turning PQ ₁ ON and OFF. When the iron stops moving, the bottom of the case 7 that houses the ball 8 is sloped to prevent the ball 8 from coming onto the photointerrupter, so the phototransistor PQ ₁ is turned off. .
PD ₁ and PQ ₁ constitute the usage state detection section 1 shown in FIG.

IC ₁ is a timer IC, with resistor R ₁ and capacitor
A time constant circuit of C ₁ is connected and the time constant (R ₁
×C ₁ ) and outputs a signal to the output terminal OUT PUT of IC ₁ after a specified time T. Before the specified time T, the output terminal becomes High level, and after the specified time T elapses, the output terminal becomes Low level. In addition, IC ₁ has a reset terminal Reset, which counts time when it is at a high level, and when it goes to a low level, a reset is completed and the time count value is returned to zero. Therefore, when the iron is used, high and low signals are repeatedly applied to the reset terminal, so that IC ₁ starts a time counting operation and is reset to zero. For this reason, it is not possible to time count up to the specified time T, and the output terminal
OUT PUT is always at High level. When the output terminal of IC ₁ is High, transistor Q ₁ turns on,
Relay R _L is ON and its contact 10 is kept ON.

If you leave the iron unused,
No light enters phototransistor PQ ₁ , PQ ₁ is OFF,
Therefore, the reset terminal of IC ₁ is kept at a high level and a time counting operation is performed. When the specified time T has elapsed, the output terminal OUT PUT of IC ₁ becomes low level, transistor Q ₁ turns OFF, and the relay
R _L is turned OFF, the contact 10 is also turned OFF, and the current to the heater 6 is cut off.

When the iron is moved, PQ ₁ turns ON, the reset terminal of IC ₁ goes to low level, IC ₁ is reset, and the time counting operation resumes from the next time the reset terminal of IC ₁ goes to high level. Also
The output terminal of IC ₁ also becomes High level, transistor Q ₁ , relay R _L and contact 10 are turned on, current is supplied to heater 6, and normal operation is restored.

Also, when the thermostat 11 is OFF, a high level DC voltage is applied to the base of the transistor Q ₂ from the resistor R ₆ , the diode D ₄ , the resistor R ₇ , and the capacitor C ₂ , and the thermostat 11 is ON. The configuration is such that a low level voltage is applied at times. Therefore, thermostat 11 is OFF.
When thermostat 11 is on, transistor Q ₂ is on and the collector voltage is low level, and when thermostat 11 is on, transistor Q ₂ is off and the collector voltage is low.
Becomes High.

IC ₁ has a STOP terminal that temporarily stops the time counting operation; when the STOP terminal is at a high level, normal operation is performed, and when the STOP terminal is at a low level, the time counting operation is temporarily stopped. In other words, the time count operation by IC ₁ is performed when the STOP pin is high.
This is the cumulative value of the time spent at the level.

Therefore, every time the thermostat 11 is turned off,
The time counting operation of IC ₁ is stopped, and the total time while the thermostat 11 is ON is counted.

_IC1 , _R1, and _C1 constitute the timer section 2 shown in FIG. 1, and the transistor _Q2 section constitutes the ON/OFF signal detection section 5.

Effects of the Invention As described above, according to the present invention, it is possible to realize an iron with an extremely simple circuit configuration and a function of detecting whether the iron has been turned off without malfunction.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing a circuit for detecting whether the iron has been turned off in accordance with an embodiment of the present invention, Fig. 2 is a cross-sectional view of an embodiment of the usage state detection sensor used in the present invention, and Fig. 3 is the temperature of the iron. control characteristic diagram,
FIG. 4 is a circuit diagram showing one embodiment of the present invention. 1... Usage state detection section, 2... Timer section, 3
...Shutoff section, 4...Temperature control section, 5...ON,
OFF signal detection section, 6...Heater.

Claims (1)

[Claims] 1. A usage state detection part that turns on and off when the iron is used, a timer part that is reset by a signal from this usage state detection part, a cutoff part that shuts off the heater after the specified time of the timer part has passed, and a A temperature control section that controls ON and OFF, and detects the ON and OFF signals of the heater from this temperature control section and turns it off.
This iron has an ON/OFF signal detection section that stops the time count operation of the timer section when a signal is detected, and accumulates the time count operation of the timer section when a heater ON signal is detected.