JPS6117352B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a surface heating element.

Conventionally, surface heating elements have generally been manufactured in the following manner. That is, a metal foil for a heat generating circuit is pasted on an insulating sheet, a prescribed circuit is printed on the surface of the metal foil using resist ink, and unnecessary parts of the metal foil are removed by an etching method to form a heat generating circuit. An insulating sheet for covering is attached to the forming surface to form the main body of the surface heating element.

On the other hand, an auxiliary sheet is created by laminating a metal foil such as aluminum foil on the surface of a plastic film having a temperature resistance coefficient such as nylon, and this auxiliary sheet is overlaid and integrated with the main body of the surface heating element.
The metal foil on the surface makes it possible to detect the temperature of the entire surface of the surface heating element and to detect electric shock caused by pinpricking from the outside.

By the way, when forming the heating circuit by the printing-etching method, the cylinder diameter of the printing machine is usually
Since it is 300 to 400mm, the circuit size is 1300mm in length.
Circuits with a length of 1800 mm, such as those for electric carpets and electric blankets, required extra large printing machines, causing high costs. Also, when forming this circuit by a punching method, a special large-sized machine is similarly required.

Therefore, a method is being used to connect these small-area circuits to form a large circuit. In this method, as shown in FIGS. 1 and 2, a unit circuit is formed of a heat generating metal foil 4 having a terminal portion 2 for circuit connection and a loop portion 3 for forming a circuit at an end portion 1. The insulating layer 5 is made continuous by the terminal portion 2.
and a metal foil 6 for temperature and electric shock detection on the other side to form a surface heating element 7, and this surface heating element 7 is cut into the size of the required number of unit circuits. The loop portion 3 in the middle portion and the terminal portion 2 at one cut end are punched out, and the terminal portion 2' at the other cut end is used as a power supply connection end.

However, although this method allows a large circuit to be easily obtained, there is a problem in that the metal foils 4 and 6 are easily short-circuited at the portion where the loop portion 3 and the terminal portion 2 are punched out.

Therefore, in order to prevent this short circuit, as shown in FIG. 3 and FIG. A method for manufacturing the heating element 9 has been proposed. That is, as explained based on FIG. 1, this method is a unit circuit consisting of a heat generating metal foil 4 having a terminal portion 2 for circuit connection and a loop portion 3 for forming a circuit at the end portion 1. are arranged on one side of the insulating layer 5 in a continuous state through the terminal portion 2, and as shown in FIGS. 3 and 4, on the other side excluding the position facing the end 1 A metal foil 6 for temperature and electric shock detection is arranged as a surface electrode, and both outer surfaces are covered with insulating films 10 and 11 to form a surface heating element 9. That is,
The missing portion 8 is provided in the metal foil 6. Then, this surface heating element 9 is cut into a length that is an integral multiple of the unit circuit, and one terminal portion 2 of the cut end and the loop portion 3 of the intermediate portion are punched out to obtain a surface heating element of a certain size. It is.

In addition to the method described above, the metal foils 4 and 6 can be arranged on the insulating layer 5 by using a plastic film such as nylon, which has a temperature resistance coefficient, as the insulating layer 5, and metal foils such as aluminum foil or copper foil on both sides of the insulating layer 5. By pasting them together, printing resist ink for the heat generating circuit on the metal foil on one side, and printing resist ink on the metal foil on the other side except for the part corresponding to the punched part of the heat generating circuit, and etching it. You can also do this.

According to this method, a circuit with a large area can be obtained by forming small unit circuits in a continuous state and partially punching out unnecessary parts. Since the metal foils 4 and 6 are arranged so as not to overlap, there is no risk that the metal foils 4 and 6 will be short-circuited at the punched portion, resulting in poor insulation.

However, according to this method, since the structure of the surface heating element 9 is a very thin layer (the metal foils 4 and 6 are
~30 μm, and the insulating layer 5 is 30 to 100 μm), and in the case of continuous manufacturing, the tensile force increases and the tensile strength of the missing portion 8 decreases, wrinkles occur, and the dimensional stability of the insulating layer 5 worsens. A problem arises.

Therefore, an object of the present invention is to provide a method for manufacturing a surface heating element that allows a large circuit with good insulation to be easily obtained, and that does not prevent wrinkles from occurring and does not deteriorate the dimensional stability of the insulating layer. be.

An embodiment of the present invention will be described based on FIGS. 5 and 6. That is, in the proposed method, the entire portion of the surface electrode 6 facing the end 1 was removed by the notch 8, but in this method, as shown in FIGS. 5 and 6, the notch 8
Instead of removing the entire inner part, the central part 12 is left and only the surrounding area is removed. In the case of using the punching method, this central part 12 is
It is formed by heavy punching, and when printing and etching is used, the resist ink is printed on the metal foil that will become the surface electrode 6 only in the areas corresponding to the surface electrode 6 and the center part 12, that is, the center The area around the portion 12 is left unprinted and is formed by etching. The other manufacturing methods are the same as the manufacturing method of the surface heating element 9 of the above-mentioned proposed example.

As described above, according to this method, by forming small unit circuits in a continuous state and partially punching out unnecessary parts, it is possible to obtain a circuit with a large area. There is no possibility that the metal foils 4 and 6 on the upper and lower surfaces of the metal foils 4 and 6 will be short-circuited, resulting in poor insulation. Furthermore, the central portion 12 is located within the cutout portion 8.
As a result, the area of the metal foil 6 to be removed can be small, and as a result, it is possible to prevent a decrease in tensile strength during continuous manufacturing, and to prevent wrinkles and a decrease in dimensional stability.

As described above, the method for manufacturing a surface heating element of the present invention is a method for manufacturing a surface heating element by punching and cutting a sheet-like body including a plurality of continuous unit heater circuits and a surface electrode facing them. In the manufacturing method of the unit heater circuit, a region of the surface electrode corresponding to the punching and cutting position of the unit heater circuit is removed in advance, leaving the center part and surrounding it, so that a large circuit with good insulation can be easily obtained. is possible,
Moreover, it has the effect of preventing wrinkles from occurring and not deteriorating the dimensional stability of the insulating layer.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a conventional surface heating element, FIG. 2 is an enlarged sectional view of a conventional surface heating element, and FIG. 3 is a perspective view illustrating the manufacturing method of a surface heating element, which is the basis of the present invention. , FIG. 4 is a sectional view of the main part, FIG. 5 is a perspective view illustrating an embodiment of the present invention, and FIG. 6 is a sectional view of the main part. 4... Metal foil (unit circuit), 6... Metal foil (plane electrode), 8... Missing part, 12... Central part.

Claims (1)

[Claims] 1. In a method for manufacturing a surface heating element, in which a sheet heating element is manufactured by punching and cutting a sheet-like body including a plurality of continuous unit heater circuits and a surface electrode facing them, the punching and cutting positions of the unit heater circuits are determined. A method for manufacturing a surface heating element, characterized in that a region of the surface electrode corresponding to the region of the surface electrode is removed in advance, leaving a central portion and the periphery thereof.