JPH02165590A - Cord form heating element - Google Patents

Abstract

PURPOSE:To enable the switching to small and large consumed electric powers with a simple structure by providing two kinds of heating wires having large and small resistance values, and using one of them as a heating source and the other as a short-circuit wire for ensuring the safety in the case of an excessive temperature increase. CONSTITUTION:A heating body has a first heating wire 1 spirally wound on the circumference of an insulating layer 5 and a second heating wire 2 spirally wound on the circumference of a core wire 4 which has a resistance value larger than the first heating wire 1, or has the lower heating amount and the lower consumed power. In this way, two heating wires 1, 2 having various resistance values are provided, and one of them being used as a heating wire with the other being used as a short-circuit wire, and this state is switched inversely. Hence, the consumed power can be freely switched, as occasion demands.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is a flexible cord-shaped heating element used in electric blankets, electric carpets, etc. The cord-shaped heating element is capable of switching power consumption. It's about the body.

[Prior Art] FIG. 3 is a partially cutaway perspective view showing a conventional cord-shaped heating element. In the figure, 11 is a heating wire made of copper wire, etc.; 3
4 is a short-circuit wire made of a conductive material, 4 is a core wire made of a thermosetting flexible insulator such as polyester fiber, and 5 is a core wire made of a thermoplastic resin such as polyamide resin.
60 to 180°C), the insulating layer 6 covers the heating wire 11 with an outer sheath made of a flexible insulator such as polyvinyl chloride resin. The shorting wire 3 is spirally wound around the core wire 4, the insulating layer 5 covers the periphery of the shorting wire 3, and the heating wire 11 is spirally wound around the insulation N5.

This cord-shaped heating element is laid in a serpentine shape inside an electric blanket, electric carpet, etc. along with another temperature detection wire for temperature control, and is a heat source that is energized from a power supply via a temperature controller (not shown). was used as.

FIG. 4 is a diagram showing an example of a protection circuit when the temperature of the conventional cord-shaped heating element increases.

In the figure, 7 is a heat generating resistor, 8 is a temperature fuse provided near the heat generating resistor 7, SO is a main switch,
The three above are usually housed in a control box.

If a needle sticks into a part of the cord-shaped heating element and the heating wire 11 and the short-circuit wire 3 are short-circuited, or if a large pressure is applied to a part of the cord-shaped heating element, resulting in a short-circuit condition, or for other reasons, the cord-shaped heating element When the temperature rises abnormally and exceeds a certain temperature,
The insulating layer 5 between the heating wire 11 and the shorting wire 3 in that part melts at once, and the heating wire 11 and the shorting wire 3 become conductive. Then, the heating resistor 7 connected between the shorting wire 3 and the power source is energized, so the heating resistor 7 generates heat, and this heat generation causes the temperature of the cord-shaped heating element interposed between the power source and the above-mentioned cord-shaped heating element to increase. The fuse 8 is blown and the power to the heating element 11 is cut off.

In this way, safety against temperature rises was ensured.

[Problems to be Solved by the Invention] The above-mentioned conventional cord-shaped heating element is constructed as described above, and has only 15 types of built-in zero heating wires 11 whose temperature is controlled by turning ON and OFF electricity to the heating wires 11. For example, after the temperature of an electric blanket or electric carpet has risen to the appropriate temperature, in order to perform fine temperature control with low power consumption, temperature control must be rough. Lay two or more cord-shaped heating elements inside a blanket or electric carpet, energize all cord-shaped heating elements at first, and then energize only one cord-shaped heating element after the temperature rises. I had to do something like switch to reduce power consumption. As a result, the structure becomes complicated and the manufacturing cost of the electric appliance using the cord-shaped heating element becomes high.

The present invention was made in order to solve these problems, and provides a cord-shaped heating element that can switch power consumption between large and small levels with a simple configuration, and by using this cord-shaped heating element, the structure can be improved. The purpose is to obtain simple and inexpensive electric blankets, electric carpets, etc. whose power consumption can be switched.

[Means for Solving the Problem] In addition to the heating wire wound around the insulating layer, the cord-shaped heating element according to the present invention replaces the short-circuit wire of the conventional cord-shaped heating element with the heating wire, and changes the resistance value of the reheating wire. be different,
One side is used as a heating wire and the other as a shorting wire.

[Function] The cord-shaped heating element of the present invention is provided with two heating wires having different resistance values, and when one of them is used as a heating wire, the other is used as a short-circuit wire, and By switching this state in the opposite direction, power consumption can be freely switched as necessary.

[Embodiment] FIG. 1 is a partially cutaway perspective view showing a cord-shaped heating element which is an embodiment of the present invention. The same or equivalent parts as in FIG. 3 are indicated using the same reference numerals, and detailed explanation thereof will be omitted. In the figure, 1 is a first heating wire wound spirally around an insulating layer 5, 2 is a first heating wire wound spirally around a core wire 4, and its resistance value is larger than that of the first heating wire 1;
That is, it is a second heating wire that consumes low power and generates a low amount of heat.

The structure of the cord-shaped heating element shown in FIG. 1 is such that the heating wire 11 of the conventional cord-shaped heating element shown in FIG.
However, the short circuit wire 3 is replaced with the second heat generating wire 2, and the rest is exactly the same.

For example, the amount of heat generated by the heating wire 1 is approximately equal to that of the conventional heating wire 11, and the amount of heat generated by the heating wire 2 is approximately 273 times that of the conventional heating wire 11. Therefore, the second heating wire 2
The current flowing through the heating wire 11 can be reduced to approximately 2/3 of that of the conventional heating wire 11.

When using the heating wire 1 as a heat generation source, use the heating wire 2 as a short-circuit wire, and when using the heating wire 2 as a heat generation source, use the heating wire 1 as a short-circuit wire to switch the power consumption from large to small. Can be done.

Next, an example of how to ensure safety and use the cord-shaped heating element, which is an embodiment of the present invention shown in FIG. 1, will be described.

FIG. 2 is a circuit diagram showing an example of a protection circuit when the temperature of the cord-shaped heating element shown in FIG. 1 rises excessively.

The same or equivalent parts as in FIG. 4 are indicated using the same reference numerals, and detailed explanation thereof will be omitted.

In the figure, SL, S3 are changeover switches provided at both ends of the heating wire 1, S2. S4 is a changeover switch provided at both ends of the heating wire 2, and the changeover switches 81 to S4 can be changed all at once manually or automatically.

Now, as shown in the figure, the changeover switches 81 to S4 are set to a
If both ends of heating wire 1 are connected to the power supply and main switch SO, and both ends of heating wire 2 are connected to heating resistor 7, heating wire 1 is connected to the heating source and heating wire 2 is connected to the heating resistor 7. will act as a shorting line.

As in the case explained with reference to FIG. 4, if for some reason the temperature of the cord-shaped heating element continues to rise, and the whole or part of it reaches a high temperature and exceeds a certain temperature, the insulating layer 5 in that part will melt. , the heating wire 1 and the heating wire 2 are short-circuited, and a short-circuit current flows into the heating resistor 7.

An example of resistance values in actual use is that the resistance value of heating wire 1 is 15.6Ω, the resistance value of heating wire 2 is 25Ω,
The resistance value of the heating resistor 7 is 1200Ω, but the potential of the short-circuited part is always lower than the potential of the power supply, so the heating wire 1
Even if there is a short circuit in any part of the heating wire 2, the short-circuit current will have a current value that causes the heating resistor 7 to generate sufficient heat. When the heating resistor 7 generates heat, the temperature fuse 8 placed near it will melt. , power to the cord-shaped heating element is cut off, ensuring safety.

When the changeover switches 81 to S4 are switched to the b side, the heating wire 1 works as a short circuit line and the heating wire 2 works as a heat generation source, and safety in the event of an excessive temperature rise can be ensured as before.

Electric appliances using this cord-shaped heating element
(2), and in order to quickly raise the temperature at the initial stage of energization, selector switches SL, S3°S2. S4 is set to side a, heat generating line 1 with a large calorific value is used as a heat generation source, heat generating line 2 is used as a short circuit line, and the main switch SO is turned on.

Then, the heating wire 1 is energized to generate heat, and the power consumption becomes 640W. After that, the temperature rises, and when it reaches the desired temperature, switch the changeover switch to the b side, and make the heating wire 1 a short-circuit wire and the heating wire 2 the heat source, and the current consumption will be 400W. The amount of heat generated can be lowered, allowing fine temperature control.

It goes without saying that the above-mentioned changeover switches 81 to S4 can be switched manually or automatically by a temperature control unit that operates in response to a signal from a temperature detection line installed together with the cord-shaped heating element. Nor.

Further, in the above embodiment, the resistance value of the second heating wire 2 is made larger than the resistance value of the first heating wire 1, but in another embodiment, this is reversed, and the resistance value of the first heating wire 1 is made larger than the resistance value of the first heating wire 1. It goes without saying that the resistance value may be increased and the resistance value of the second heating wire 2 may be decreased.

[Effects of the Invention] As explained above, this invention provides two types of heating wires having large and small resistance values, uses one of them as a heat generation source, and short-circuits the other to ensure safety in the event of excessive temperature rise. Since it is configured to be used as a wire, it is possible to obtain electric blankets, electric carpets, etc. with a simple configuration and switchable power consumption while ensuring safety. As a result, after the temperature of the cord-shaped heating element has risen, the current consumption can be reduced by energizing the heating wire with a large resistance value. Pond electrical appliances can be used while using electric carpets, etc.

In addition, electric blankets using this cord-shaped heating element, etc.
It is possible to control the temperature with a low calorific value, and avoid causing sudden temperature changes or overheating to the human body, resulting in excellent hygiene.

Moreover, this cord-shaped heating element has a simple structure and can be obtained with almost no increase in manufacturing costs, which provides excellent effects.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway perspective view showing a cord-shaped heating element which is an embodiment of the present invention, and Fig. 2 shows an example of a protection circuit when the temperature of the cord-shaped heating element shown in Fig. 1 above rises. The circuit diagram and FIG. 3 are partially cutaway perspective views showing a conventional cord-shaped heating element. FIG. 4 is a diagram showing an example of a protection circuit when the temperature of the conventional cord-shaped heating element increases. In the figure, 1, 2 and 11... exothermic wire, 3... short circuit wire, 4... core wire, 5... insulating layer, 6... outer cover,
7... Heat generating resistor, 8... Temperature fuse, SO...
・Main switch, SL, S2. S3. S4... is a changeover switch. In each figure, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] Wrapping a second heating wire around a core wire made of a flexible insulator,
The surrounding area is covered with an insulating layer that melts suddenly when it reaches a predetermined temperature, the first heating wire is wound on top of that, and the first heating wire is further covered with an outer skin made of a flexible insulator. A cord-shaped heating element characterized in that the heating wires of No. 2 have different electrical resistances.