JPH04179089A - Sheet form heat emitting element and its manufacture - Google Patents

Abstract

PURPOSE:To simply and quickly fabricate a sheet form heat emitting body having a large power capacity using a simple facility at a low cost by furnishing a metal strand emitting heat when current is fed, and providing a thread which catches this metal strand within loops of strand. CONSTITUTION:A metal strand 7 emitting heat when current is fed is arranged on one of the surfaces of an insulative sheet 9, while a thread 11 to catch the strand is arranged on the other surface of the insulative sheet 9 in the same orientation as the strand 7. The thread 11 forms loops, and therewith penetrates the sheet 9, and fixes the strand 7 onto the sheet 9 by catching the strand 7 in the loops. Thus a sheet form heat emitting body can be fabricated simply and quickly without provision of any particular device for manufacture.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a sheet heating element and a method for manufacturing the same.

[Prior Art] Conventionally, a technique is known in which a resistance wire is sewn together with a thread onto an insulating sheet to form a planar heating element (for example, the
(See Japanese Utility Model Publication No. 20668, Japanese Utility Model Application Publication No. 55-64291, etc.).

With such technology, sheet heating elements, which are widely used for heat retention and heating in various fields due to their large heat generating area and freedom of shape, can be manufactured simply, quickly, and at low cost using simple equipment. I can do it.

[Problems to be Solved by the Invention] Incidentally, there is a demand for increasing the power capacity in order to increase the heat generation amount (per unit area) of a sheet heating element to which resistance wires are sewn. However, if the surface temperature of the resistance wire sewn to the planar heating element becomes too high, the heat will damage the insulating sheet and the sewing thread. Therefore, there was an upper limit (permissible current value) to the current that could be passed through the resistance wire sewn to the sheet heating element.

Therefore, in order to obtain a planar heating element with a large power capacity, the following measures can be considered.

■Sewing resistance wires with high density to the sheet heating element per unit area, increasing the length of the resistance circuit provided on the sheet heating element per unit area. This increases the resistance value of the planar heating element per unit area and applies a high voltage to it.

■Sewing a resistance wire with a larger diameter to allow a larger current to flow.

However, in the case of ■, the width of the seams is narrow, and it is necessary to prevent the seams from touching each other, which takes time and effort to manufacture and causes high costs. . Furthermore, in that case, it is also necessary to apply a high voltage.

Also, as shown in ■, it is impossible to sew a thick resistance wire onto an insulating sheet using a normal sewing machine. It is not possible to sew resistance wire onto an insulating sheet.

Here, a method of bundling a plurality of resistance wires and sewing them onto an insulating sheet may be considered.

However, simply bundling a plurality of resistance wires has the problem that the threads or the bundled resistance wires become tangled while being sewn onto the insulating sheet.

The present invention solves such problems and provides a technology that allows a planar heating element with a large power capacity (per unit area) to be manufactured simply, quickly, and at low cost using simple equipment.

[Means for Solving the Problems] The structure of the bookcase-invention for solving the above-mentioned problems is as follows. The electrically conductive heat generating metal strands are arranged along the direction in which the electrically conductive heat generating metal strands are arranged, and form loops at multiple locations and penetrate the above insulating sheet at the loops. A planar heating element characterized by comprising: a thread formed by capturing a wire;

In addition, the configuration of the second invention (using a heat-resistant thread according to the operating temperature as the upper thread of the sewing machine and using an energized heat-generating metal stranded wire as the lower thread) drives the sewing machine to sew the stitches on the insulating sheet. This is a method for manufacturing a sheet heating element, characterized in that the sheet heating element is formed by forming a sheet heating element.

[Function] This box - In the planar heating element according to the invention, the stranded metal wires that generate heat when energized are arranged on one side of the insulating sheet, and the threads that capture them generate heat when energized on the other side of the insulating sheet. The metal strands are arranged along the direction in which the metal strands are arranged. The thread forms loops at multiple locations, and the loops penetrate the insulating sheet to trap the heat-generating metal strands within the loops. This fixes the heat-generating metal strands onto the insulating sheet. Such a bookcase can be manufactured using an ordinary sewing machine.

That is, as shown in the second invention, the upper thread of the sewing machine is made of heat-resistant thread according to the working temperature, the lower thread is made of electrified heat-generating metal stranded wire, the sewing machine is driven, and the insulating sheet is By forming seams in the bookcase, the planar heating element according to the invention can be manufactured.

When sewing with a sewing machine in this way, the stranded metal wire that generates electricity and heat is wound around the bobbin as the bobbin thread (because it is made of multiple metal wires twisted together, it is more flexible than thick single wire metal wire, and the sewing machine Since it can be captured by the upper thread passed through the needle, it can be easily sewn onto an insulating sheet.

In addition, since it is made of stranded current-carrying heat-generating metal wires (the indicated number of current-carrying heat-generating metal wires twisted together), the above-mentioned allowable current value increases by the amount that a plurality of current-carrying heat-generating metal wires are twisted and bundled. Therefore, a larger current can flow, and the power capacity of the planar heating element increases.

Furthermore, since the energized heat-generating metal stranded wire is made of a plurality of metal wires twisted together, the threads or metal wires do not become entangled with each other while being sewn onto the insulating sheet.

[Example] Fig. 1 (A) shows a book case - Fig. 1 (CB) shows an enlarged cross-section of the main part of a planar heating element 1 which is an embodiment of the invention) shows a stranded metal resistance wire 7 used in the embodiment. FIG. 2 shows an enlarged schematic diagram and a perspective view of the whole.

The sheet heating element 1 has a flexible band shape as a whole, and a terminal portion 3 provided at one end is connected to a lead wire 5a.

5b is connected to both ends of the internal twisted metal resistance wire (heat-generating twisted metal wire) 7. This metal resistance twisted wire 7 is made of a nickel alloy, and is wired as shown by the dotted line in FIG.

As schematically shown in FIG. The number of metal resistance wires (single wire 7a) to be twisted can be changed as appropriate depending on the purpose. Also, the diameter of the metal resistance wires (single wire 7a) to be twisted can be varied depending on the purpose.
Selectable. Furthermore, the pitch of the twisted metal resistance strands (adjacent distance of 50.50 as shown in Figure 1 (B))
may also be changed as appropriate.

The type of metal resistance wire (single wire 7a) used for twisting,
Examples of combinations with the twist pitch of the metal resistance stranded wire are shown in Table 2 of the attached table.

The stranded metal resistance wire 7 is attached to one side 9a of the flexible insulating sheet 9.
is placed in contact with. A retaining thread 1] is arranged on the other surface 9b of the insulating sheet 9. That stopper thread]]
form loops] 1a at approximately equal intervals. loop l
la passes through the insulating sheet 9 and captures in its loop the metal resistive strands 7 on the opposite side 9a. Therefore, in this state, the metal resistance twist 1JA7 and the stopper thread 1] are the insulating sheet 9
is fixed. Furthermore, insulating sheets 13 and 15 for covers are pasted on both sides of the sheets.

When the lead wires 5a and 5b are energized in this state, the twisted metal resistance wire 7 first generates heat, and this heat is conducted throughout the planar heating element 1, and the heat is emitted to the outside in a planar manner.

This planar heating element 1 is manufactured as follows.

It should be noted that the configuration of the sewing machine to be described hereinafter is a common one, so detailed explanation thereof will be omitted.

First, as the upper thread of a sewing machine, a heat-resistant thread (stopper thread) 1) is used that corresponds to the operating temperature of the planar heating element 1. Since the stopper thread 1 as the upper thread is inserted through the needle hole, it passes through the insulating sheet 9 as the sewing machine needle moves up and down.

As the needle thread, materials ranging from ordinary sewing threads to highly heat-resistant glass braided threads, Teflon threads, etc. are used depending on the required heat resistance.

Further, a metal resistance twisted wire 7 is used as a bobbin thread, and is wound around a bobbin and placed in a bobbin case.

The insulating sheet 9 is sewn using the sewing machine adjusted in this manner, resulting in the structure shown in FIG. 3(A). The upper thread (stopping thread) 1) and lower thread (metal resistance twisted wire 7) formed at this time
) and the stitch pattern is as shown in FIG.

Since the metal resistance twisted wire 7 is a bobbin thread, it will not be bent into a loop shape during sewing. Therefore, the twisted metal resistance wire 7 will not be disconnected due to sewing.

Next, lead wires 5a are attached to both ends of the metal resistance stranded wire 7.

5b, and as shown in FIG.
Cover insulating sheet 13.15 having a layer 1
3a and 15a, and further reinforce the periphery of the terminal portion 3 with another insulating sheet and heat vulcanize using a hot press or the like. As a result, the cover insulating sheets 13 and 15 are firmly adhered to both surfaces of the insulating sheet 9, and a planar heating element 1 as shown in FIG. 1(A) is obtained. Note that the insulating sheet 9 of this embodiment has a reinforcing glass cloth 9c inside. In addition, among the surfaces of the insulating sheet 13.15 for the cover, the surface opposite to the unvulcanized silicone rubber layers 13a, 15a is the vulcanized silicone rubber layer 13b, 15b, which is the insulating sheet for the cover. 13. In the center of 15 is a reinforcing glass cloth 13c.

15c exists.

In the above sewing, straight stitches were used (Fig. 4), but zigzag stitches as shown in Fig. 5 may be used. Various sewing methods can be adopted depending on the purpose.

The planar heating element 1 of this embodiment (the metal resistance strands 7 on one surface 9a of the upper insulating sheet 9 is connected to the metal resistance strands 11 on the other surface 9b in a loop shape) 7. Therefore, the metal resistance strands 7 can be easily and quickly wired by simply sewing with a normal sewing machine.

Further 1: By using this sewing machine to manufacture a planar heating element, it is possible to freely form and select the wiring pattern, wiring position and area (by adjusting the sewing position, direction and length during front assembly). For this reason, an automatic sewing machine is used.
L It is possible to automate the production of planar heating elements with various wiring patterns, positions, and areas according to the application. Therefore,
High-mix, low-volume production can be carried out efficiently without increasing costs.

Moreover, since the stranded metal resistance wire 71 is made by twisting the single wires 7a of the metal resistance wire, it has greater flexibility per unit cross-sectional area than when using a single metal resistance wire with a large diameter. Stop thread 1, which is the upper thread threaded through the sewing machine needle
1, it is easy to be captured.

In addition, since the metal resistance twisted wire 7 (friend) is made by twisting together the single wires 7a of the metal resistance wire, it is sewn into the insulating sheet 9 using a sewing machine. Or, it does not get tangled with the stopper thread 11 used as an upper thread.

In addition, metal resistance stranded wire 7 [Table 7 Single wire of multiple metal resistance wires]
The value of the current (allowable current) that can flow through the twisted metal resistance wires 7 sewn to the planar heating element 1 according to this embodiment (used for twisting) It is approximately equal to the sum of the allowable current values that can be passed through the single wire 7a of the metal resistance wire.Therefore, the sheet heating element 11 according to this embodiment and the sheet heating element using the single wire 7a of the metal resistance wire. Compared to this, it is possible to flow a larger current, and the power capacity (per unit area) of the planar heating element 1 can be increased.

Table 1 shows the relationship between the diameter and allowable current value of metal resistance wires that can be manufactured using a normal sewing machine. This allowable current value (the upper limit of the current that is limited by the surface temperature of the metal resistance wire to prevent the surface temperature of the metal resistance wire from becoming too high and damaging the insulating sheet 9 on which the metal resistance wire is sewn) Specifically, in the experiment whose results are shown in Table 1, the allowable current value (the surface temperature of the metal resistance wire was 200°
The current value does not exceed C.

In addition, in the experiment whose results are shown in Table 1 (mu double twist,
It merely shows the allowable current value when three-stranded, four-stranded, and both single wires of the same diameter are twisted together.

As shown in Table 1, in the case of a single metal resistance wire with a diameter of 0.29 mm, the allowable current value is 1° OA. If the diameter exceeds 0.29 mm, it cannot be manufactured using a normal sewing machine because the stopper thread 11, which is a crest thread, cannot capture the metal resistance wire.

On the other hand, when using metal resistance stranded wire, the allowable current value of the maximum diameter that can be captured by the upper thread using a normal sewing machine is
It is clear from Table 1 of the attached table that the wire is larger than that of a single wire.

That is, the allowable current value of a metal resistance twisted wire made by twisting two single wires each having a diameter of 0.2 mm is 1.4A. Diameter 0.2
It is used by twisting two single wires of less than mm in diameter (i) It can be manufactured using a normal sewing machine.

Furthermore, the allowable current value of three twisted solid wires with a diameter of 0 to 2 mm is 1.8 A. It is made by twisting three single wires with a diameter of 0°2 mm or less, and can be manufactured using a 1fS normal sewing machine.

Furthermore, the allowable current value of four twisted solid wires with a diameter of 0.16 mm is 2. It is OA.

In addition, when calculated from Table 1, the total cross-sectional area of each wire when the allowable current value is the largest is 0 for a single wire (diameter 0° 29 mm).
．． 066mrr? , 2 strands (diameter 0゜2mm x 2 strands) with 0. 063mrr4, three strands (diameter 0.2mm
x3 pieces) is 0. 094mrr? , four strands (diameter 0.
16mm x 4 pieces) is 0.080mrr.

In the case of two-stranded wires, the wires are twisted together, which has a larger allowable current value even though the total cross-sectional area is smaller than that of single wires, so the surface area is larger and heat dissipates more easily. This is because it has become.

In addition, as shown in Table 2 of stranded metal resistance wire 1 used in the planar heating element according to this embodiment, the diameters of the single wires of the metal resistance wires to be twisted and the combinations of the number of strands to be twisted may be varied. I can do it. Thereby, it is possible to easily obtain stranded metal resistance wires having different resistance values per unit length, so it is easy to obtain planar heating elements with various power capacities (per unit area).

In addition, in this embodiment, the metal resistance strands 7 sewn to the insulating sheet 9 are connected in series with no crossing points. In comparison, the wiring circuit is simpler, costs are reduced, and defects are less likely to occur.

Although silicone rubber was used as the upper insulating sheet 9, 13, and 15 in the above examples, other insulating resins and rubbers can be used. : For example, Kapton (trade name, manufactured by DuPont), polyester resin (for example, MYtar (trade name, manufactured by DuPont), etc.), glass fiber-reinforced epoxy resin, etc.

Note that the present invention is not limited to the one embodiment described in detail above, but includes all embodiments that can be conceived by those skilled in the art without departing from the gist of the present invention.

[Effects of the Invention] According to the planar heating element and the method for manufacturing the same according to the present invention, it is possible to wire the current-carrying heat-generating metal strands on an insulating sheet by using an ordinary sewing machine. It can be manufactured easily and quickly without the need for

[Furthermore] According to Noboru Mimotoki, it is possible to freely wire the current-carrying heat-generating metal stranded wires to any position on the surface heating element, so it can quickly respond to changes in the wiring area and is economical. .

Moreover, since the current-carrying heat-generating metal stranded wire, which is made by twisting multiple current-carrying heat-generating metal wires, is sewn onto an insulating sheet, it is more flexible than thick metal wires, and can be easily moved by the needle thread passed through the needle of the sewing machine. Since it is easily captured, it can be easily sewn onto an insulating sheet.

In addition, since the current-carrying heat-generating metal stranded wire is made of a plurality of current-carrying heat-generating metal wires twisted together, the above-mentioned allowable current value is doubled by twisting and hand-bundling multiple current-carrying heat-generating metal wires. Therefore, it is possible to flow a larger current than usual through the sheet heating element according to the present invention, and the power capacity (per unit area) of the sheet heating element can be increased.

In addition, since the electrically heated metal stranded wire is made of a plurality of metal wires twisted together, the threads or metal wires do not become entangled with each other while being sewn onto the insulating sheet.

Table 1 Table 2

[Brief explanation of the drawing]

FIG. 1(A) is an enlarged cross-section of the main part of a planar heating element which is an embodiment of the present invention. FIG. 1(B) is an enlarged schematic diagram of a metal resistance stranded wire used in the embodiment. 1(A) is a perspective view of the entire planar heating element according to this embodiment. FIG. 3(A) is a diagram of the explanatory box 3 (B
) is an explanation of the pasting state. Fig. 4 is an illustration of straight stitching, and Fig. 5 is an illustration of zigzag stitching. ]... Planar heating element 7... Metal resistance stranded wire 9... Insulating sheet 11... Stopping system 11a
···loop

Claims (1)

[Scope of Claims] 1) Current-carrying heat-generating metal stranded wires arranged on one surface of an insulating sheet; and a current-carrying heat-generating metal stranded wire disposed on the other surface of the insulating sheet along the direction in which the current-carrying heat-generating metal strands are arranged. and a thread formed by forming loops at a plurality of locations, penetrating the insulating sheet at the loops, and trapping the energized heat-generating metal strands in the loops. A sheet heating element. 2) Using a heat-resistant thread according to the operating temperature for the upper thread of the sewing machine, and using an energized heat-generating metal stranded wire for the lower thread, the sewing machine is driven to form seams on the insulating sheet to generate surface heat. 1. A method for producing a planar heating element, the method comprising: forming a sheet heating element.