JPH0340639B2 - - Google Patents

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]

Conventionally, in a steam iron equipped with a temperature setting device, a valve is opened to allow a certain amount of water to drip into the vaporization chamber in the iron base to generate steam, and the valve is closed to stop steam generation. However, with this type, the amount of water supplied to the vaporization chamber is always constant, so if the amount of water supplied is determined based on the iron base being set to a high temperature, for example, when the iron base is set at a low temperature, the amount of water dripping will be too large. However, there was an inconvenience that the vaporization in the vaporization chamber was insufficient and water was released as water.

[Purpose of the invention]

This invention was made in order to solve such problems, and the purpose is to provide a steam iron that can drip water suitable for the temperature of the iron base into the vaporization chamber and can always release good steam. shall be.

[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. The water in the water tank installed at the top of the base is supplied to the vaporization chamber formed in the iron base by controlling the opening and closing of a valve using a solenoid, and a variable resistor is connected to the temperature setting operation of the temperature setting device. The duty ratio of the energization cycle to the solenoid is variably controlled in the direction of increasing when the temperature setting value is large.

[Embodiments of the Invention] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

As shown in Figure 1, 1 is an iron base, and this iron base 1 has two steam outlet ports at both ends.
A vaporization chamber 3 is formed in which gas chambers a and 2b are provided. Further, the iron base 1 houses a heater 4 and a negative characteristic thermistor 5 as a temperature detection element. A circuit component storage part 8 having a water tank storage part 6 at the front and a handle 7 at the rear is mounted on the upper part of the iron base 1. A valve 1 is provided at the bottom of the water tank 9 of the water tank storage section 6 and includes a nozzle 10 that communicates with the vaporization chamber 3 and a needle valve 11 that opens and closes the nozzle 10 by vertical motion.
2 are provided. The upper end of the needle valve 11 is attached to the lower end of the plunger 13, and the plunger 1
A spring 14 is attached to the upper end of the needle valve 3 to always bias the plunger 13 in the direction in which the needle valve 11 closes the nozzle 10. A solenoid 15 is provided around the plunger 13, and the solenoid 15
When energized, the plunger 13 and needle valve 11
is raised against the spring force to open the nozzle 10.

Figure 2 shows the circuit configuration.
The input terminal of a full-wave rectifier circuit 23 is connected to the input terminal of the full-wave rectifier circuit 23 via a power switch 22. The full wave rectifier circuit 23
A smoothing capacitor 24 is connected to the output terminal of. A first voltage dividing circuit 27 is formed by connecting resistors 25 and 26 in series to the smoothing capacitor 24, and a second voltage dividing circuit is formed by connecting a sliding variable resistor 28 as a temperature setting device and the thermistor 5 in series. A voltage dividing circuit 29 and a third voltage dividing circuit 32 formed by connecting resistors 30 and 31 in series are connected to each other. Further, a first relay 34 is connected to the smoothing capacitor 24 via an NPN type first transistor 33, and the normally open contact 3 of the first relay 34
The heater 4 is connected via 4 m. A connection point between the resistors 25 and 26 is connected to the inverting input terminal (-) of the comparator 35, and a variable resistor 28,
The connection point of the thermistor 5 is connected to the non-inverting input terminal (+) of the comparator 35. The comparator 35
The output terminal of the transistor 30 is connected to the connection point of the resistors 30 and 31 and also to the base of the first transistor 33. The first and third voltage dividing circuits 2
7, 32, the first transistor 33, the first relay 34, and the comparator 35 form a heater control circuit. Furthermore, the smoothing capacitor 24
the second transistor 36 of the NPN type
The second relay 37 is connected, and the solenoid 15 is also connected via the normally open contact 37m of the second relay 37. An astable multivibrator 39 whose duty ratio of the oscillation cycle changes according to the setting of a sliding variable resistor 38 is provided, and the output of the vibrator 39 controls on/off of the second transistor 36. In addition,
This multivibrator 39 is configured to be started, for example, by operating a switch. The second transistor 36, the second relay 37 and the astable multivibrator 39 form a solenoid control circuit. Each of the variable resistors 28,
38 are interlocked with each other, and the variable resistor 38 is also variably controlled by the variable operation of the variable resistor 28. Then, the variable resistor 28 sets the temperature of the iron base 1 to a high temperature by decreasing its resistance value, and at this time, the duty ratio of the oscillation period of the astable multivibrator 39 is increased by the variable resistor 38, and the second The on-time of the transistor 36 is controlled to be longer.

In the embodiment of the present invention configured in this way,
When the temperature of the iron base 1 is set with the variable resistor 28 and the power switch 22 is turned on, the temperature of the iron base 1 is initially low, so the resistance value of the thermistor 5 is large and the output of the comparator 35 becomes high level. Therefore, the first transistor 33 is turned on,
The first relay 34 is activated and its normally open contact 34m
is closed and energization of the heater 4 is started. In this way, the iron base 1 is heated by the heater 4 and its temperature is increased. As a result, the resistance value of the thermistor 5 decreases, and when it eventually reaches the set temperature of the variable resistor 28, the output of the comparator 35 is reversed to low level, the first transistor 33 is turned off, and the power to the heater 4 is cut off. It will be done. Thereafter, the first transistor 33 is repeatedly turned on and off depending on the temperature state of the iron base 1, and the power to the heater 4 is turned on.
The temperature of the iron base 1 is maintained approximately at the set temperature by the off control. When a switch is operated in this state to operate the astable multivibrator 39, the multivibrator 39 oscillates at a duty ratio based on the resistance value of the variable resistor 38, and turns on the second transistor 36 periodically. This causes the second relay 37 to operate periodically, and the solenoid 1
5 operates periodically. As a result, the needle 11 periodically opens and closes the nozzle 10, and the water in the water tank 9 is dripped into the vaporization chamber 3, vaporized, and discharged from the steam discharge ports 2a, 2b.
At this time, the amount of water dripping from the water tank 9 to the vaporization chamber 3 is determined by the duty ratio of the energization cycle to the solenoid 15, which is determined according to the temperature setting of the iron base 1 by the variable resistor 28, so that the amount of water dripping from the water tank 9 to the vaporization chamber 3 is determined by the duty ratio of the energization cycle to the solenoid 15, so that the amount of water dripping is appropriate and good steam is produced. Can be released.

If the set temperature of the variable resistor 28 is lowered in this state, the electricity to the heater 4 is cut off until the temperature drops to the new set temperature, and the temperature of the iron base 1 drops to the set temperature. According to this change in the set temperature, the resistance value of the variable resistor 38 also changes, and the duty ratio of the turn-on period of the second transistor 36 by the multivibrator 39, that is, the energization period to the solenoid 15 becomes smaller. As a result, the amount of water dripping from the water tank 9 to the vaporization chamber 3 is suppressed to a small amount, and becomes an appropriate amount that matches the temperature of the iron base 1. Therefore, even at this time, water is not released as is, and steam can be released favorably.

Although slide type variable resistors are used as the variable resistors 28 and 38 in the above embodiment, they are not necessarily limited to this, and may be of a step type for switching a plurality of resistors, for example.

〔Effect of the invention〕

As described in detail above, according to the present invention, water suitable for the temperature of the iron base can be dripped into the vaporization chamber that generates steam, and a steam iron can be provided that can always discharge good steam.

[Brief explanation of the drawing]

FIG. 1 is a partial sectional view showing an embodiment of the present invention;
FIG. 2 is a circuit diagram of the same embodiment. 1... Iron base, 3... Vaporization chamber, 4...
Heater, 5...Negative characteristic thermistor, 9...Water tank, 12...Valve, 15...Solenoid, 27
...First voltage divider circuit, 28... Variable resistor, 32
...Third voltage divider circuit, 33...First transistor, 34...First relay, 35...Comparator, 3
6... Second transistor, 37... Second relay, 38... Variable resistor, 39... Astable multivibrator.

Claims (1)

[Claims] 1. 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, and a temperature detection element that detects the temperature of the iron base.
a heater control circuit that compares the temperature detection output of the temperature detection element with the temperature setting output of the temperature setting device and controls energization of the heater according to the set temperature;
A water tank provided at the top of the iron base, a valve that supplies water from the water tank to the vaporization chamber, a solenoid that controls the opening and closing of this valve, and a solenoid that periodically energizes the solenoid. a control circuit, and a variable resistor that is linked to the temperature setting operation of the temperature setting device and variably controls the duty ratio of the energization cycle to the solenoid by the solenoid control circuit, and the variable resistor is configured to adjust the temperature setting value of the temperature setting device. The steam iron is characterized in that the duty ratio of the energization cycle to the solenoid is varied in the direction of increasing as the energization period increases.