JPS5847000A - Water leakage preventing apparatus of 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 An object of the present invention is to provide a simple and reliable water leakage prevention device for a steam iron using a shape memory alloy.

A shape memory alloy is a metal that undergoes a phase transformation inside the metal by heating and cooling near its transformation point, changing its shape and at the same time generating a strong transformation force. In other words, after shaping this alloy into a state that you want to memorize, and then heat-treating it to retain that shape, you can do something like this at a temperature below the transformation point. When it is heated to a transformation point (transformation temperature), it returns to its original memorized shape with a strong transformation force. Alloys with this property are generally made of T1/Ni alloy or Cu-Zn-X (X is a metal element that affects the properties of memory alloys), and depending on the blending ratio, the physical properties of the alloy Properties can be changed in various ways.

The present invention mainly applies the property of shape change at the transformation point of this shape memory alloy to a water leakage prevention device for a steam iron, and will be explained in detail below with reference to the drawings while making a comparison with a conventional example.

FIG. 1 shows a general steam iron. Reference numeral 1 denotes a base heated by a heater 2, and includes a vaporizing chamber 6 for vaporizing water droplets dripping from a valve seat 4 provided on a cover 3. Further, the steam vaporized in the vaporization chamber 6 passes through the passage 6 and is ejected from the steam ejection lower. A water tank 8 has a water inlet 9 and drops water droplets into the vaporization chamber 6 of the base 1 through the valve seat 4. 1o is a rod having a needle-shaped opening/closing valve 11 at its lower end, which is made to fit into a small hole in the valve seat 4. 12913 is a spring, and the spring 12 is made to extend upward, and the spring 13 is made to extend downward, and normally in a state where there is no external force, the force with which the spring 12 extends is stronger than the force with which the spring 13 extends. It looks like this. 14 is a button that moves the rod 1o up and down. For example, once the button 14 is pushed beyond the force of the spring 12, the rod 10 is lowered and the opening/closing valve 11 closes the small hole of the valve seat 4, so that the water tank 8 Water droplets inside will not fall. In this case, although not particularly shown in the drawings, a locking device is provided that allows the rod 10 to stop at the pressed position even when the pressing force of the button 14 is removed. When the button 14 is pressed again, the water droplets fall into the vaporizing chamber 6, and the steam vaporized in the vaporizing chamber 6 is ejected from the ejection lower part of the base 1, thereby functioning as a steam iron. Reference numeral 16 denotes a thermostat made of bimetal that keeps the temperature of the base 1 constant, and the rotary knob 16 allows an adjustment rod 17 to move up and down to adjust the set temperature.

The above is general 2. Although the structure and operation of the steam iron have been explained, a potential problem with this type of steam iron is that if the user opens the on-off valve 11 while the base 1 is not heated to a temperature sufficient to generate steam. ,
Water flows out from the spout lower of the base 1 in a liquid state, which is a problem.

The present invention uses a shape memory alloy to solve this problem in a simple and reliable manner. That is, in the present invention, instead of the spring 12, a shape memory alloy 12' in the shape of a coil spring yf that has been subjected to shape memory treatment in the stretched state is used.
Figure 3 is a wiring diagram for this, in which a shape memory alloy 12' is connected in series with the heater 2, and a shunt resistor 1i is provided in parallel with this shape memory alloy 12'. , adjust the current through the shape memory alloy 12' to an appropriate level.

That is, when the shape memory alloy 12' self-heats due to the current flowing through the shape memory alloy 12' and reaches the transformation point, ~
The rod 1 expands by overcoming the stretching force of the spring 13.
Raise o. Therefore, the value of the shunt resistor 18 is selected so that the base 1 reaches a temperature at which steam can be generated before the opening/closing valve 11 is opened.

With the above configuration, even if the user turns on the power and releases the button 14 to open the on-off valve 11, it will not open or close until the shape memory alloy 12' reaches its transformation point. When the valve does not open and the transformation point is reached, the shape memory alloy 12'
is exerted by the tension of the spring 13 to pull up the rod 10 and open the on-off valve 11. At this time, as mentioned earlier, the temperature of the base 1 has risen to the point where steam is generated, so steam is generated without liquid water flowing out.

Also, if you turn off the power immediately after completing the work, the shape memory alloy 12' will cool down, so the tension force of the spring 13 will be stronger, and the rod 1o will be pushed down and the on-off valve 11 will be closed, so the button 14 will be closed. There is no risk of water flowing out even in the unlocked state. In the conventional devices, water will flow out unless the button 14 is locked after the work is completed.

Note that there is also a method of using the heat of the base 1 to heat the shape memory alloy 12', but in this case, the base 1 is connected to the power source.
Since the water does not cool down immediately even when the water is turned off, it takes a long time to close the on-off valve after the work is finished, and during that time the base 1 cools and water flows out. In this respect, the above-mentioned embodiment utilizes self-heating, so the response is fast, and as mentioned above, water outflow can be completely prevented. Also, as can be seen from the wiring diagram, the thermostat 16 is QN-O during steam generation.
Because of FIF, the on-off valve 11 opens and closes each time, and it seems that steam only comes out intermittently, but in reality,
Since the OFF time of the thermostat is about 20 seconds, the thermostat 16 is turned ON until the shape memory alloy 12' cools down and closes the on-off valve, so steam is generated continuously. In addition, if you want to use it as a dry iron with the on-off valve 11- closed, please lock the button 14.
Even if the shape memory alloy 12' is heated and tries to expand,
Since it cannot be expanded and the on-off valve 11 does not open, it can be used as a dry iron.

As described above, the present invention uses a shape memory alloy so that the opening/closing valve opens only when the base is at a temperature that allows steam to be generated, thereby preventing water leakage in a simple and reliable manner. can be done, and the effect is great.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view of a general steam iron, FIG. 2 is a sectional view of a main part showing an embodiment of the device of the present invention, and FIG. 3 is a circuit diagram of the same device. 1...Base, 4...Valve seat, 6...
... Vaporization chamber, 12' ... Shape memory alloy, 13
... Spring, 14 ... Button, 1
6...Thermostat. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 3
plan

Claims (1)

[Claims] ■ A shape memory device that is heated by a heater and has a vaporization chamber, a water tank that has an on-off valve that drips water into the vaporization chamber, and that generates heat by itself due to the heating current of the heater. A water leak prevention device for a steam iron in which the opening/closing valve is opened by a shape change at the transformation point of the alloy. (2) A water leakage prevention device for a steam iron according to claim 1, wherein a shape memory alloy is connected in series with a heater for heating the base. (2) A water leakage prevention device for a steam iron according to claim 1, wherein a shunt resistor is provided in parallel with the shape memory alloy.