JPS6025836Y2 - Continuous sheet for surface heating elements - Google Patents

Description

[Detailed explanation of the idea] This invention relates to a continuous sheet for surface heating elements.

The conventional planar heating element shown in FIGS. 1 and 2 has a planar temperature detection circuit 2 formed of metal foil on the upper and lower surfaces of a plastic layer 1 having a temperature resistance coefficient, respectively, and a planar temperature detection circuit 2 also formed of metal foil. A zigzag heater circuit 3 is formed, and insulating sheets 4 and 5 are attached to the outside of each circuit 2.3.

In this case, the heater circuit 3 is formed in such a manner that the same pattern A is repeatedly and continuously printed at a printing pitch of a fixed length to form a continuous circuit.

Therefore, in order to obtain a surface heating element of the required length, one end is cut at the boundary line of each pattern A, and the other end is cut at a position that is an integral multiple of the length of each pattern A.

That is, in order to obtain a surface heating element twice the length of pattern A, for example, it was cut at cutting positions A and A in FIG.

However, as shown in FIG. 2, the surface heating element cut in this way has the temperature detection circuit 2 widely exposed on the cut surface, and the entire cut surface must be insulated. The problem was that it was extremely difficult.

Therefore, an object of this invention is to provide a continuous sheet for a planar heating element whose cut surfaces can be easily insulated.

An embodiment of this invention is shown in FIGS. 3 and 4.

That is, this planar heating element is used in place of the conventional planar temperature detection circuit 2 shown in FIGS. 1 and 2, as shown in FIGS.
This uses the planar temperature detection circuit 6 shown in the figure.

This planar temperature detection circuit 6 is similar to the conventional planar temperature detection circuit 2.
The difference is that a part of the boundary line of each pattern A, that is, the planned cutting line of the continuous sheet for a surface heating element is removed.

For convenience, the part that has become narrower due to partial removal is referred to as the narrower width part 6.
The wide portion 6b is referred to as a wide portion 6b.

As can be seen from FIG. 4, this narrow portion 6a is formed at a position facing the terminal portion 3a of the heater circuit 3.

Because of this structure, when a surface heating element is constructed by cutting this continuous sheet for a surface heating element along the boundary line of pattern A, the cut surface has thin strips as shown in FIGS. 4 and 5. Since the width portion 6a and the terminal portion 3a appear only in a part of the cut surface, it is only necessary to insulate that portion, and there is no need to insulate the entire cut surface, making it easy to insulate the cut surface.

This embodiment is especially effective when a wide surface heating element is used.

Another embodiment of this invention will be described with reference to FIGS. 6 and 7.

That is, this continuous sheet for a planar heating element uses a planar temperature detection circuit 7 shown in FIGS. 6 and 7 instead of the planar temperature detection circuit 6 shown in FIG. (Figures 1 and 7 show the surface heating element after cutting).

This planar temperature detection circuit 7 has a narrow portion 7a and a wide portion 7b corresponding to the narrow portion 6a and wide portion 6b of the planar temperature detection circuit 6.
In addition, each thick portion 7b is provided on the side of the narrow portion 7a.
It has a terminal portion 7d that is electrically connected to the terminal portion 7c via a conductive portion 7c.

The other configurations are the same as the above embodiment.

Because of this structure, when this continuous sheet for a surface heating element is cut as shown in FIG. Since the portion 7C and the terminal portion 3a of the heater circuit 3 are present only on a part of the cut surface, there is no need to insulate the entire cut surface, which facilitates the insulation treatment.

Moreover, when the planar temperature detection circuit 7 is disconnected, the disconnection can be detected to prevent excessive temperature rise and fire due to abnormal temperature control.

To do this, in FIG. 6, the conductive portion 7C is
At the same time, a lead wire is connected to the narrow part 7a and the terminal part 7d at the left end in FIG. A disconnection detection/circuit breaker device that detects a disconnection between 7d and cuts off the power supply to the heater circuit 3 is connected.

By doing so, even if the sheet temperature detection circuit 7 is disconnected at the narrow portion 7a located approximately at the center of the sheet heating element, the disconnection can be detected and
The circuit breaker immediately operates to stop the power supply to the heater circuit 3, thereby reliably preventing excessive temperature rise of the surface heating element and fire.

Note that the reason why the punching section 8 is used is that if the punching section 8 is not punched out, the narrow section 7 located approximately in the center of the surface heating element will be removed.
This is because if wire a is broken, only the left half of the planar temperature detection circuit 7 will work and the right half will not, making temperature control impossible.

As described above, the continuous sheet for a surface heating element of this invention has a heater circuit in which the same pattern is repeatedly repeated to form a continuous circuit, and a heater circuit that faces the heater circuit and faces the boundary line of each pattern of the heater circuit. A continuous sheet for a planar heating element having a planar temperature detection circuit with a narrow width at a portion where the heater circuit is connected, wherein the planar heating element is constructed by cutting the pattern of the heater circuit at any two points of the boundary line. Therefore, there is an effect that the insulation treatment on the cut surface becomes easy.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway plan view of a conventional continuous sheet for a surface heating element, Fig. 2 is a sectional view taken along the line ■-■ of Fig. 1, and Fig. 3 is a partially cutaway plan view of an embodiment of this invention. Figure 4 is TV-I of Figure 3.
V sectional view, FIG. 5 is a partially cutaway plan view of a cut surface heating element, FIG. 6 is a plan view of another embodiment of this invention, and FIG. 7 is a sectional view of ■=■ in FIG. 6. be. 3...Heater circuit, 3a...Terminal, 6
, 7... Planar temperature detection circuit, 6a, ? a...
...Narrow width part, 7b...Thick width part, 7d...
...Terminal section.

Claims (1)

[Scope of utility model registration request] A surface having a heater circuit in which the same pattern is repeatedly repeated to form a continuous circuit, and a planar temperature detection circuit that faces the heater circuit and has a narrow width at a portion facing the boundary line of each pattern of the heater circuit. A continuous sheet for a surface heating element, the sheet heating element being constructed by cutting the heater circuit pattern at any two boundary lines.