JPS602299A - Steam 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 relates to a steam iron equipped with a temperature setting device.

[Technical background of the invention and its problems J Conventionally, steam irons enable steam injection when the temperature of the iron base falls within an appropriate temperature range near the temperature set by the temperature setting device. The heat is temporarily absorbed by the heat of vaporization, and the temperature drops temporarily. In such cases, there is a problem in that when the temperature of the iron base falls below the appropriate temperature range, the steam injection stops.

[Purpose of the invention]

This invention was made to solve this problem, and by using a simple circuit configuration such as a thyristor and a relay, once the temperature of the iron base reaches the appropriate temperature and steam is ejected, the iron base will no longer be heated. To provide a steam iron capable of maintaining Nattemost steam jet even if the temperature is below an appropriate temperature.

[Summary of the invention]

This invention compares the temperature detection output of a temperature detection element that detects the temperature of the iron base with the temperature setting output of a temperature setting device that sets the temperature of the iron base, and controls the power supply to the heater according to the set temperature. An electromagnetic valve is installed at the bottom of the water tank installed at the top of the base, and an appropriate temperature signal is output from the appropriate temperature judgment circuit when the temperature detection output of the temperature detection element is within the appropriate temperature range determined based on the temperature setting output. is applied to the gate of the thyristor, and a relay connected in series to this thyristor holds the appropriate temperature signal output state of the appropriate temperature determination circuit until the set temperature is changed, and during that holding period, the solenoid valve is opened and the steam is turned off. It performs injection.

[Implementation sequence of the invention]

Hereinafter, an embodiment IFII of the present invention will be described with reference to the drawings.

As shown in FIG. 1, reference numeral 1 denotes an iron base, and this iron base L has a vaporizing chamber 3 provided with steam discharge ports 2a and 2b at both ends. Further, the iron base I houses a heater 4 and a thermistor 5 with a negative characteristic as a temperature detection element. A circuit component storage part 8 having a water tank 6 at the front and a handle 7 at the rear is attached to the soil part of the iron base l.

A nozzle 9 serving as a communication hole communicating with the vaporization chamber 3 is provided at the bottom of the water tank 6 .

The nozzle 9 is provided with a long needle valve 10 that opens and closes its hole by vertical movement.

The needle valve 10, the plunger IZ to which the upper end of the needle valve IO is attached, the spring body 12 that keeps the plunger II constantly downward, and the plunger II
A solenoid valve is formed by the lunoid 13 which urges the valve upward against the spring force of the spring body Z2.

Figure 2 shows the circuit configuration, in which a series circuit of the temperature setting device I5 and the thermistor 5, a series voltage dividing circuit of resistors 16, 17, 18, and 19, and a heater control circuit 20 are connected between the +vO terminal and the ground. Connected. Note that +vO is created by rectifying and smoothing the AC power supply. The temperature setting device 15 is constructed by connecting five series circuits of resistors and switches in parallel with different resistance values, and by selectively turning on the switches, the resistance value of the resistor inserted in the circuit is changed and the temperature is adjusted. Settings are being made. The heater control circuit 2
0 is resistance zr.

A control relay 25 is connected in parallel to the collector side of the transistor 24 through a first transistor 24 of NPN type to the series circuit of 22 and 23.
The heater 4 is connected via the normally open contact 25m of the Iil relay 25. and the first transistor 2
4 is connected to the connection point of the resistors 22 and 23. The connection point P between the temperature setting device 15 and thermistor 5 is connected to the non-inverting input terminal (G) of the first comparator 26, and the connection point B of the resistor 17.18 is connected to the inverting input terminal (G).
c). The output terminal of the first comparator 26 is connected to the connection point of the resistor 21.22. In addition,
The resistance value of the resistor 16 and the resistance value of the resistor 19 are made equal, and the resistance value of the resistor 17 and the resistance value of the resistor 18 are made equal.

The connection point of the resistor 16.17 is connected to the non-inverting input terminal (→) of the second comparator 27, and the resistor 18.1
Connect the connection point of 9 to the inverting input terminal (c) of the third comparator 28.
is connected to. A switching contact that connects the inverting input terminal (C) of the second comparator 27 and the non-inverting input terminal ← of the third comparator 28 and serves as a first contact of a relay 29 whose connection point will be described later. It is connected to the connection point P via the normally closed side of the switching contact 29B, and to the connection point B via the normally open side of the switching contact 29S. Said 2nd. The output terminals of the third comparators 27 and 28 are connected to diodes 30 and 3, respectively.
1 to each other in the opposite direction, and the connection point is connected to the resistor 3.
2 to the +Vo4 terminal, and is grounded via a Zener diode 33 and a resistor 34 in series.

A series circuit consisting of a resistor 36 and a light emitting diode 37 for displaying an appropriate temperature is connected to the collector side of the transistor 35 via a second NPN transistor 35 between the +Vo terminal and the ground, and the base of the transistor 35 is connected to the Zener. Even if the connection point between the diode 33 and the resistor 34 is connected, the second. Third comparator 27.2B, diode 30,3
1. Zener diode 33, resistor 32, 34, 36,
A circuit including the second transistor 35 and the light emitting diode 37 constitutes an appropriate temperature determination circuit. In addition, a series circuit consisting of a resistor 38, a steam switch 39, and a light emitting diode 40 for indicating steam operation is connected between the +Va terminal and the ground, and a dry switch is connected in conjunction with the resistor 41 and the steam switch 39 to turn on and off in reverse. 42
A series circuit of a light emitting diode 43 for indicating dry operation is connected.

Furthermore, the relay 29 is connected in series between the +vO terminal and the ground through a reset switch 44 and a thyristor 45, which are turned off for a short time in response to switching of the temperature setting device I5 and turning off of the steam switch 39. Normally open contact 29m as the second contact of 29
The solenoid 13 is connected through the solenoid 13. The connection point between the resistor 36 and the light emitting diode 37 is connected to the diode 46.
is connected to the inverting input terminal (c) of the fourth comparator 47 through a forward direction, and the connection point between the resistor 38 and the steam switch 39 is connected to the fourth comparator 47 through a diode 48 in the forward direction. The inverting input terminal (c) is connected to K. The fourth comparator 47 has its inverting input terminal (C) further grounded via a resistor 49, and its non-inverting input terminal ←)
is connected to a reference voltage terminal Vref, and its output terminal is connected to the gate of the thyristor 45 via a resistor 50.

Therefore, the appropriate temperature signal of the appropriate temperature determination circuit is applied to the gate of the thyristor 45 via the diode 46, the fourth comparator 47, and the resistor 50.

Next, the operation of the embodiment of the present invention constructed as described above will be described.

First, a desired temperature is set by selectively operating a switch on the temperature setting device 15. When a power switch (not shown) is turned on in this state, -1-Va is input to the circuit shown in FIG. Now, the temperature of the iron base 1 is low and the resistance value of the thermistor 5 is sufficiently larger than the resistance value of the temperature setting device Z5.

On the other hand, the voltage VB at the connection point B is vO/2. Therefore, the output of the first comparator 26 is greater than the voltage vpH-1vB at the connection point P.

In this way, the first transistor 24 is turned on, the control relay 25 is operated, the normally open contact 25m of the control relay 25 is turned on, and energization to the heater 4 is started. Further, when the temperature of the iron base I is lower than the lower limit of the appropriate temperature range, the voltage VP is higher than the voltage vA at the connection point A and the second comparator 2
The output of 7 becomes low level. Therefore, the Zener diode 33 and the second transistor 35 are not turned on and the appropriate temperature determination is not performed. When the iron base I is heated by the heater 4 and its temperature gradually decreases, the resistance value of the thermistor 5 decreases, and the voltage Vp gradually decreases. And Vp≦V
When the signal becomes A, the output of the second comparator 27 is inverted to high level. On the other hand, since the voltage VP is higher than the voltage VD at the connection point, the output of the third comparator 28 is also at a high level.

As a result, the Zener diode 33 and the second transistor 35 are turned on, and the light emitting diode 37 displays an appropriate temperature.

In this state, if you turn on the steam switch 39, the fourth
The input level to the inverting input terminal (c) of the comparator 47 becomes low level, and the output of the comparator 47 rises to high level, turning on the thyristor 45. However, relay 2
9 is activated, its normally open contact 29m is turned on, and energization to the solenoid 13 is started, the needle valve 10 is raised and the nozzle 9 is opened, and the water in the tank 6 drips into the vaporization chamber 3, creating steam. Occurs, steam release port,? Steam is injected to the outside from a+2b.

Also, when the holding relay 29 operates, its switching contact 298
switches and the normally open side turns on. However, from then on, the outputs of the second and third comparators 27 and 28 both maintain a high level regardless of the temperature of the iron base I, that is, the resistance value change of the thermistor 5. Further, the thyristor 45 is also turned on and the holding relay 29 continues to operate. . Therefore, even if the temperature of the iron base I reaches the lower limit of the appropriate temperature range at the set temperature, that is, vP>vA due to the heat of vaporization at the point where steam is generated, the appropriate temperature determination circuit maintains the appropriate temperature determination, and the thyristor 45 becomes conductive. The state is maintained to maintain the operating state of the holding relay 29.

Thereafter, when a switch is operated to vary the set temperature of the temperature setting device I5, the reset switch 44 is turned off for a short time, and the thyristor 45 is turned off.

As a result, the operation of the holding relay 29 is stopped, the solenoid 13 is turned off, the needle valve 1o closes the nozzle 9, and the generation of steam is stopped. At this time, the normally closed side of the switching contact 29S of the holding ring 29 returns to the on state, so the heating determination circuit does not determine the appropriate temperature until the temperature of the iron base l falls within the appropriate temperature range at the new set temperature, and steam is generated. will not be carried out.

In this way, once the temperature of the iron base 1 falls within the appropriate range of the set temperature, steam generation will be maintained unless the set temperature is changed, so the temperature of the iron base I will drop below the appropriate temperature by the injection of steam. However, this does not stop the steam injection.

The relay 29, which is kept energized in response to the conduction of the thyristor 45, uses its switching contact 29s to connect the variable voltage input terminals of the second and third comparators 27.2p to the fixed voltage terminal (Va /2) and closes the normally open contact 29m to operate the solenoid I3. Thus, the appropriate temperature signal output state of the appropriate temperature determination circuit can be maintained with a simple circuit configuration such as a thyristor and a relay, and the above-mentioned functions can be provided.

〔Effect of the invention〕

As explained above, according to the present invention, by using a simple circuit configuration such as a thyristor and a relay, once the temperature of the iron base reaches the appropriate temperature and steam is injected, the temperature of the iron base becomes the appropriate temperature. It is possible to provide a steam iron that can be maintained even when the temperature is below and improves practicality.

[Brief explanation of the drawing]

FIG. 1 is a partial sectional view showing an embodiment of the present invention, and FIG. 2 is a circuit configuration diagram of the same embodiment. I... Iron base, 3... Vaporization chamber, 4... Heater, 5... Thermistor, 5... Water tank, 9...
・Nozzle, 10... Needle valve, 13... Solenoid, 15... Temperature setting device, 16, 17.18.19.
...Resistance, 20...Heater control circuit, 26, 27
, 28°47... Comparator, 29... Relay, 29
s...Switching contact (first contact), 29m...Normally open contact (second contact), 45...Thyristor.

Claims (1)

[Claims] A vaporization chamber formed in the iron base, a heater that heats the iron base, a temperature setting device that sets the temperature of the iron base, a temperature detection element that detects the temperature of the iron base, and a temperature detection element that detects the temperature of the iron base. A heater control circuit that compares the temperature detection output with the temperature setting output of the temperature setting device and controls the energization of the heater according to the set temperature, a water tank provided at the top of the iron base, and the water tank. an electromagnetic valve provided at the bottom of the device to control the opening and closing of the communication hole to the vaporization chamber, and whether the temperature detection output of the temperature detection element is within an appropriate temperature range determined based on the temperature setting output of the temperature setting device. an appropriate temperature judgment circuit that determines whether the temperature is on and outputs an appropriate temperature signal when the appropriate temperature is on, a thyristor to which the appropriate temperature signal from this appropriate temperature judgment circuit is applied to the gate and conducts in response to the appropriate temperature signal, and a thyristor connected in series to this is kept energized in response to conduction of the thyristor, and maintains the appropriate temperature signal output state of the appropriate temperature determination circuit at the first contact until the set temperature K of the temperature setting device is varied, and at the same time, the second contact and a relay that controls opening of the electromagnetic valve in response to the output state of the appropriate temperature signal.