JPS5913999Y2 - electric iron - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electric iron using a positive temperature coefficient thermistor as a heat source.

In conventional electric irons, a sheathed heater is embedded in the base or a mica heater is pressed into contact with the base, and the base is heated by these heaters.

The temperature of this base was also controlled by opening and closing a heater circuit using a bimetal.

However, in the conventional structure described above, since a bimetal is provided separately from the heater, the structure is complicated and requires a large space.

Furthermore, since temperature control is performed by opening and closing the heater circuit, there are various disadvantages such as radio wave interference, wear and burn-out of contacts, and temperature ripples in the base temperature cannot be avoided.

The present invention was developed based on these circumstances, and its purpose is to use a plurality of positive temperature coefficient thermistors with different Curie points as heat sources, and to selectively energize these positive temperature coefficient thermistors to achieve the above-mentioned results. The purpose of this invention is to provide an electric iron that can eliminate these drawbacks.

Hereinafter, one embodiment of the present invention will be described based on the drawings.

In the figure, reference numeral 1 denotes a base, and a plurality of, for example, three positive temperature coefficient thermistors 2, 3.degree. 4 are attached to the upper surface of the base 1 in close contact with each other.

These positive characteristic thermistors2. 3. 4 each differ by one Curie point, the first PTC thermistor 2 has a Curie point of 100°C, the second PTC thermistor 3 has a Curie point of 150°C, and the third PTC thermistor 4 has a Curie point of 200°C. It becomes.

In addition, these positive temperature coefficient thermistors 2. 3. 4 is held down by a holding plate 5 attached to the markings 1a, 1a of the base 1.

Further, a cover 6 is fitted onto the base 1, and this cover 6 is fixed by a boss 7.

A handle 10 is attached to the upper surface of the cover 6 with a stopper 8 and a bolt 9.

Insertion holes 6a, 10a are formed in the center of the upper surface of the cover 6 and in the center of the lower part of the handle 10, respectively, and the operation shaft 11 is inserted into the insertion holes 6a, 10a.

A movable contact piece 13 of a rotary switch 12 mounted within the cover 6 is attached to the lower end of the operating shaft 11.

Further, the upper end of this operating shaft 11 is connected to a cover 6 and a handle 10.
The operation dial 1 for temperature adjustment protrudes from the bottom of the
4 is installed.

When the operating dial 14 is rotated, the movable contact piece 13 of the rotary switch 12 is rotated via the operating shaft 11, so that the operation described below is performed.

The electric iron having the above structure has an electric circuit shown in FIG.

That is, each positive temperature coefficient thermistor 2°3.4 is selectively connected to the power source 15 via the rotary switch 12.

In detail, the movable contact piece 13 switches in three stages,
At the first rotation angle, it is connected to the first fixed contact 16, at the second rotation angle, it is simultaneously connected to the second fixed contact 17 and the third fixed contact 18, and at the third rotation angle, it is connected to the fourth fixed contact 16. It is connected to the contact 19, the fifth fixed contact 20, and the sixth fixed contact 21 at the same time.

First fixed contact 16, second fixed contact 17, fourth fixed contact 1
9 is connected to the first positive temperature coefficient thermistor 2, the third fixed contact 18 and the fifth fixed contact 20 are connected to the second positive coefficient thermistor 3, and the sixth fixed contact 21 is connected to the third positive coefficient thermistor 4. It is connected to the.

In an electric iron with such a configuration, operation knob 1
4 to move the movable contact piece 13 of the rotary switch 12.
For example, when the movable contact piece 13 is turned to the first rotation angle, the movable contact piece 13 is connected to the first fixed contact 16 as described above, and therefore only the first PTC thermistor 2 is energized.

Therefore, this first positive temperature coefficient thermistor 2 generates heat and heats the base 1.

The temperature of the base 1 is approximately 100'C since the Curie point of the first positive temperature coefficient thermistor 2 is 100'C.
Controlled at °C.

Also, by turning the operation dial 14 and connecting the movable contact piece 13 of the rotary switch 12 to the second fixed contact 17 and the third fixed contact 18, the first positive temperature coefficient thermistor 2 and the second positive coefficient thermistor 3 can be connected. are connected in parallel with each other and energized.

Therefore, both positive temperature coefficient thermistors 2 and 3 generate heat until the base 1 temperature reaches 100°C, and when the temperature exceeds 100°C, only the second positive coefficient thermistor 3 generates heat and heats the base 1.

Then, the temperature of the base 1 is determined by the second positive temperature coefficient thermistor 3.
Since one point of Curi is 150'C, it is about 150°
Controlled by C.

Next, when the movable contact piece 13 of the rotary switch 12 is connected to the fourth fixed contact 19, the fifth fixed contact 20, and the sixth fixed contact 21 at the same time, all the positive temperature coefficient thermistors 2, 3.
4 are energized in parallel with each other.

All the positive temperature coefficient thermistors 2.3.4 generate heat until the temperature of the base 1 reaches 100°C, and from 100°C to 150°C, the second positive temperature coefficient thermistor 3 and the third positive temperature coefficient thermistor 3 generate heat. Thermistor 4 generates heat and the third
Only the positive temperature coefficient thermistor 4 generates heat.

The temperature of the base 1 is determined by the third positive temperature coefficient thermistor 4.
Since the temperature of one cucumber is 200°C, approximately 200°C
Controlled at °C.

In this way, the positive characteristic thermistor 2. 3. Since the base 1 is heated by the heat generated from the base 1, it has excellent rapid heating properties.

In addition, since the temperature is controlled by changing the thermal output of the positive temperature coefficient thermistor 2°3.4 itself, there is no need to use bimetal, and the iron itself can be made more compact with a simple structure.

Further, since there is no opening/closing operation of the heating element circuit when controlling the temperature of the base 1, there is no radio wave interference, no temperature ripple, and various problems caused by contact wear and seizure are eliminated.

Furthermore, when the control temperature of the base 1 is set to 150°C, the first positive temperature coefficient thermistor 2
Until the temperature reaches C, heat is generated together with the second positive temperature coefficient thermistor 3, so that the heating characteristics can be improved.

Furthermore, when the temperature of the base 1 is set to 200°C, the first positive temperature coefficient thermistor 2 generates heat up to 100°C, the second positive coefficient thermistor 3 generates heat up to 150°C, together with the third positive coefficient thermistor 4. Therefore, the heating characteristics can be improved in the same way as above.

In addition, in the above embodiment, three positive temperature coefficient thermistors that differ by one Curie point were attached to the base, but in the present invention,
The number of positive temperature coefficient thermistors is not limited as long as it is two or more.

As explained above, the present invention uses a positive temperature coefficient thermistor as a heat source, so it not only has fast heating properties, but also can obtain a desired temperature by selectively energizing a plurality of thermistors with different Curie points. Therefore, there is no need for a separate temperature control mechanism, the structure related to temperature control is extremely simple, and the iron itself can be made more compact.

Furthermore, since the heating element circuit does not have an opening/closing part such as a bimetal switch, it is possible to prevent radio wave interference, eliminate temperature ripples, and prevent various problems caused by wear and seizure of contacts.

Furthermore, according to the present application, when the base temperature is set to a low temperature, only the positive temperature coefficient thermistors with a low cue point are energized, and as the base temperature is set to a high temperature, positive temperature coefficient thermistors with a high cue point are sequentially added and energized. Therefore, as the set temperature of the base increases, the number of thermistors that generate heat increases and the heat dissipation area increases, and the newly added thermistor only has to generate heat until it reaches its own cue point. Become.

Therefore, especially when ironing different types of fabric by increasing the temperature stepwise from a low temperature range to a high temperature range, the heating time required to reach the desired temperature when the temperature is switched to a high temperature range is It has various excellent effects, such as shorter heating times and improved heating characteristics.

[Brief explanation of the drawing]

The figures show an embodiment of the present invention, with FIG. 1 being a sectional view of an electric iron, and FIG. 2 being an electric circuit diagram thereof. 1...Base, 2. 3. 4... Positive characteristic thermistor, 6... Cover, 10... Handle, 11... Operating shaft, 12... Rotary switch, 13... Movable contact piece, 14... Operating dial, 16 , 17.18.19
．． 20.21... Fixed contact.

Claims (1)

[Scope of utility model registration request] It is equipped with a plurality of positive temperature coefficient thermistors with different cue points that serve as heat sources attached to a common base, and a switch that controls the energization of these positive temperature coefficient thermistors. An electric iron characterized in that a switching connection is made so that only the positive temperature thermistor with a low cue point is energized, and as the base temperature is set to a high temperature, positive temperature thermistors with a high cue point are sequentially added to energize.