JPS6128396Y2 - - Google Patents

Description

[Detailed explanation of the idea]

Industrial Application Field The present invention relates to planar heating appliances such as electric carpets and electric mats. BACKGROUND TECHNIQUE Conventionally, this type of planar heating device, as shown in FIG. The cord-shaped heating wire 3a and temperature sensing wire 4a, each of which is covered with vinyl chloride, are buried by adhesive fixing in step 5, and placed on the upper surface of these with a heat-fusible film 6 interposed therebetween. The heat-sealing mat 1 and the surface material 7a are integrally joined by thermocompression bonding to melt the heat-fusible film 6 of these laminated structures, thereby forming the heating wire 3a and the temperature detection wire 4a. was buried in trench 2. Problems to be Solved by the Invention The planar heating device configured as described above has the following drawbacks, and improvement thereof has been desired. (1) Since there is a gap between the outer periphery of the heating wire 3a and the temperature detection wire 4a buried in the groove 2 and the groove 2, heat conduction to the surface side of the surface material 7a is poor and heat generation occurs. The wire 3a is likely to cause local overheating. (2) Connect the heating wire 3a and the temperature detection wire 4a to one groove 2.
If the grooves 2 are buried, they will cross each other during the burying process and breakage will occur during the subsequent heat-compression bonding process. It takes time for the temperature detection line 4a to detect the heat generated from the heat generation line 3a in the temperature detection line 3a, and the detection ability is poor. (3) Insulating mat 1 is made of fibers such as cotton, hemp, wool, polyester, polyamide, acrylic, polypropylene, etc., which are needle punched and then impregnated with resin such as acrylic, vinyl acetate, etc. to make them dense and hard. Grooves 2 are formed by heat pressing. Because it is a shaped device, it cannot be folded as a planar heating device, making it inconvenient to carry or store, for example, on a large-area electric carpet. In addition, when the heating wire 3a and the temperature detection wire 4a are thermally bonded in the manufacturing process of planar heating equipment or used for a long period of time, the heat-generating wire 3a and the temperature detection wire 4a shrink due to heat, but the heat-insulating mat 1 is highly dense and impregnated with resin, so it is difficult to shrink due to heat. As a result, uneven wrinkles were generated on the surface material 7a, or stress was applied to the heating wire 3a and the temperature detection wire 4a, resulting in a problem of deterioration of durability and life performance. Furthermore, during the manufacturing process, the heating wire 3a and the temperature detection wire 4
a tends to jump out of the groove 2, and if it is integrally joined with the surface material 7a in that state, there are problems such as crushing, disconnection, or unevenness on the front side of the surface material 7a. (4) The work process of applying the fixing tape 5 to bury and fix the heating wire 3a and the temperature detection wire 4a in the groove 2 takes a long time by hand and cannot be automated, so there is a problem that it is not suitable for mass production and increases manufacturing costs. had. Means for solving the problem A heat-fusible coating layer formed by extrusion coating is coated on the outer periphery of the heating wire and temperature detection wire coated with vinyl chloride, and the heat-fusible coating layer is heat-fused. A heater unit is formed by integrally heat-sealing the heat-sealing membrane, and this heater unit is interposed between a low-density insulating mat with a flat top surface and the surface material, and is integrated by thermocompression bonding. and the thickness t of the heat-fusible coating layer is greater than or equal to the thickness t ₁ of the heat-fusible film. Function The heat-fusible coating layer provided on the outermost part of the heating wire and the temperature detection wire is joined to a low-density heat-insulating mat whose upper surface is flat, and the thickness of the heat-fusible coating layer is The following effects can be expected by forming a heater unit and making it thicker than the heat-fusible film for integrally joining the surface material and the heat insulating mat. (1) Do not create air gaps around the heat generating wires and temperature detection wires. (2) The spacing between the heating wire and the temperature detection wire can be reduced. (3) Can be made into a flexible planar heating device. (4) The heat shrinkage rate of the heating wire or temperature detection wire and the insulation mat can be made to be the same. (5) The heating wire and temperature detection wire will not be crushed or broken during the manufacturing process. (6) Work efficiency improves. Embodiment Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. Figure 1 shows a cross-sectional view of the main parts of an embodiment of the planar heating device of the present invention, in which 3 is a cord-shaped heating wire that generates heat, and 4 is a cord-shaped heating wire that generates heat from the heating wire 3. A cord-shaped temperature detection line to be detected; 11 is a heat-fusible coating layer made of polyolefin, such as polyethylene or vinyl acetate, formed in advance by extrusion coating on the outermost part of the heating wire 3 and the temperature detection line 4; 8 is a meandering Cotton, linen, wool, etc. are used to bury the heat generation wire 3 and temperature detection wire 4 and have a heat insulating effect.
Low-density insulating mat made of fibers such as polyester, acrylic, polypropylene, etc. or miscellaneous hair finished by needle punching to have a flat top surface with no grooves. The density surface material 10 is a heat-fusible film made of polyolefin, such as polyethylene or vinyl acetate, which integrally joins the surface material 7 and the heat insulating mat 8, and the heat-fusible coating layer 11 has a thickness t of The thickness of the fusible film 10 is t ₁ or more, and the heating wire 3 and the temperature detection wire 4 are embedded in the heat insulating mat 8 in a meandering manner by being fused and fixed to the disconnection mat 8 and the heat fusible film 10. It has the function of fixing. FIG. 2 is a detailed view of the heating wire 3 shown in FIG. 1, where 16 is a core thread made of heat-resistant fiber, such as polyester, glass, etc., and 15 is a metal conductor, for example, wrapped around the outer circumference of the core thread 16. The heating element wire 14 made of copper or copper alloy is a polyamide composition formed by extrusion coating around the outer periphery of the core yarn 16 and the heating element wire 15, and the impedance decreases significantly or melts in abnormal temperature conditions. 13 is a temperature fuse layer 14 having a characteristic of
12 is made of vinyl chloride formed by extrusion coating around the outer periphery of the temperature fuse layer 14 and the detection wire 13. Insulating jacket 11 is a heat-fusible coating made of polyolefin, such as polyethylene, vinyl acetate, etc., which is formed into a 0.2 to 0.4 mm material by extrusion coating around the outer periphery of insulating jacket 12, a composite material, a polymer material, etc. This heating wire 3 is structurally easy to be arranged in a meandering manner, and by providing the heat-fusible coating layer 11, it can be fixed after being arranged in a meandering manner. FIG. 3 is a detailed view of the temperature detection line 4 shown in FIG. 1, in which 21 is a core yarn made of heat-resistant fiber, 20 is a primary electrode wound around the outer circumference of the core yarn 21, and 19 is a core yarn 21 and a heat-sensitive layer 18 formed by adding 1 to 5% of a surfactant to a vinyl chloride composition having a negative temperature coefficient, such as vinyl chloride, molded around the outer periphery of the primary electrode 20 by extrusion coating.
9 is a secondary electrode wrapped around the outer periphery of the secondary electrode; 17 is a shielding layer made of a heat-resistant film provided around the outer periphery of the secondary electrode to prevent migration of additives in the vinyl chloride composition of the heat-sensitive layer 19; 11 is an insulating jacket made of vinyl chloride molded by extrusion coating around the outer periphery of the shielding layer 17, and 11 is a heat-fusible coating layer with a thickness of 0.2 to 0.4 mm provided around the outer periphery of the insulating jacket 12. This temperature detection line 4 is connected to a temperature control circuit (not shown) that detects the impedance of the heat-sensitive layer 19 between the primary electrode 20 and the secondary electrode 18 and controls the current flowing through the heating element wire 15 of the heating line 3. By providing the heat-fusible coating layer 11, the heating wire 3 can be installed and fixed in a meandering manner in parallel with the heating wire 3. FIG. 4 shows a cross-sectional view of the heater unit 9 constituting the planar heating device shown in FIG. 1 before being integrated and joined. 3 is a heating wire, and 4 is a meandering arrangement in close proximity to the heating wire 3. 10 is a polyolefin-based heat-fusible film having a thickness of 0.1 to 0.2 mm, 1
1 is a 0.2~
It is a heat-fusible coating layer made of polyolefin with a thickness of 0.4 mm, and the heating wire 3 and the temperature detection wire 4 are integrated by thermocompression bonding at the contact portion between the heat-fusible coating layer 11 and the heat-fusible film 10. It can be fixed to the heat-fusible film 10 in a planar meandering shape by heat-sealing it to the heat-fusible film 10. FIG. 5 shows the thickness of the heat-fusible film 10 that integrally joins the surface material 7 and the heat insulating mat 8 shown in FIG.
This shows the adhesive strength characteristics when changing t _1. Practical adhesive strength is good if the thickness is about 0.1 mm or more, but since it is saturated at 0.2 mm or more, Considering economy, the optimal value of _t1 is 0.1 ~
It is 0.2mm. Next, the operation of the above configuration will be explained in detail. Since the insulating jacket 12 of the heating wire 3 and the temperature sensing wire 4 is made of vinyl chloride, it exhibits flexibility without being greatly affected by temperature, has good moldability, and is made of inexpensive material. By embedding the heat-generating wire 3 and the temperature-sensing wire 4, which are provided with a heat-fusible coating layer 11 by extrusion coating, in a low-density heat-insulating mat 8 whose upper surface is flat, the heat-generating wire 3 and the temperature-sensing wire 4 are It can be arranged and fixed in a meandering manner without creating any gaps around the outer periphery. Furthermore, even if the heating wire 3 and the temperature sensing wire 4 are so close that their parallel spacings touch, there will be no problem in manufacturing the heater unit, and the wires can be buried in the heat insulating mat 8. The reason why the thickness t of the heat-fusible coating layer 11 is set to be greater than or equal to the thickness t ₁ of the heat-fusible film 10 is as follows. (1) The heat-adhesive film 10 must have the ability to integrally bond the surface material 7 and the heat insulating mat 8 without peeling during long-term use. As is clear from the results in FIG. 5, when t ₁ <0.1 mm, the adhesive strength is weak and cannot withstand long-term use. while t ₁
> 0.2 mm, the adhesive strength is almost saturated; as the thickness increases, the adhesive becomes hard and rigid, reducing the foldability of the planar heating device. Due to the increased volume, thermocompression bonding takes a long time, and as a result, the insulation jackets 12, 12 of the heating wire 3 and the temperature detection wire 4 are deformed by heat, and furthermore, the material cost increases. It is not preferable because of such things. For the above reasons, the thickness t ₁ of the heat-fusible film 10 is
0.1 to 0.2 mm can be said to be optimal in terms of practical performance. (2) Table 1 shows the results of investigating the characteristics when the thickness t of the heat-fusible coating layer 11 was changed. Table 1 will be explained below.

[Table] In the table, uniform film property is the film property when the heat-fusible coating layer 11 is formed by extrusion coating on the outermost part of the heating wire 3 and temperature detection wire 4, and is thinner than 0.2 mm. In this case, the coating thickness becomes uneven and the moldability is poor. Meandering arrangement refers to the workability of arranging the heating wire 3 and the temperature detection wire 4 in a meandering manner to obtain the heater unit 9. If t is thicker than 0.4 mm, the rigidity of the cord-like object will increase. This is not preferable because it becomes difficult to bend into a meandering shape. Adhesion with the heat-adhesive film means that in thermocompression bonding to form the heater unit, if t is thinner than 0.2 mm, the vinyl chloride insulating jacket 12 may be thermally deformed and its insulation properties may be reduced, or heat may be applied. Since sufficient adhesion strength between the fusible film 10 and the heat-fusible coating layer 11 cannot be obtained, a heater unit 9 is interposed between the surface material 7 and the heat insulating mat 8, and heat generation occurs before they are integrally joined by thermocompression bonding. The wires 3 or the temperature detection wires 4 may come off from the heat-fusible film 10 and cross each other, resulting in crushing during thermocompression bonding or creating unevenness on the surface of the surface material 7, which is undesirable from the viewpoint of performance and appearance of the product. . The adhesion with the heat insulating mat means that the heat generating wire 3 and the temperature detection wire 4 are buried in the heat insulating mat 8 during thermo-compression bonding, but the needle-punched heat insulating mat 8 becomes multiple, so it must be heat fused. sexual coating layer 11
is the adhesive strength that acts to harden the fibers of the heat insulating mat 8. If t is thinner than 0.2 mm, the heat-adhesive covering layer 11 cannot sufficiently fix the fibers of the heat-insulating mat 8, and when folded or mechanical stress is applied to the sheet heating device, it will peel off and become the heating wire 3. There is a possibility that the temperature detection line 4 may cross. Therefore, if the condition of t≧0.2 mm is satisfied, the durable life of the planar heating device can be ensured. Thermal conductivity is the result of examining the initial rapid heating property of the surface material 7 from when a current is applied to the heating wire 3 until it reaches saturation, and when t ₁ <0.1 mm, the heating wire 3 is buried. In this case, the density is low near the boundary with the heat-insulating mat, and when t≧0.5 mm, the heat-sealing effect of the heat-adhesive coating layer 11 is produced instead of low density, so 0.2 to 0.4 mm
A thickness of . Thus, from the results shown in Table 1, the thickness t of the heat-fusible coating layer is preferably 0.2 to 0.4 mm in terms of practical performance. Therefore, as is clear from the detailed contents of FIG. 5 and Table 1, the thickness t of the heat-fusible coating layer 11 is
The thickness t ₁ of the heat-fusible film 10 is 0.1 to 0.2 to 0.4 mm.
~0.2 mm is preferable, so if the configuration satisfies the relationship t≧ _t1 , there will be no gap between the heat generating wire 3 and the temperature detection wire 4 and the heat insulating mat 8, and the distance between the heat generating wire 3 and the temperature detection wire 4 will be They can be arranged side by side in a meandering manner with a small space between them, and can prevent crushing of the heating wire 3 and temperature detection wire 4 and occurrence of irregularities on the surface of the surface material 7 during the manufacturing process. In the final product of the planar heating device, the heat-fusible coating layer 11 and the heat-fusible film 10 are heat-fused and melted into the fibers of the heat-insulating mat 8 and the surface material 7, respectively, during the integral bonding process by thermocompression bonding. However, since the fibers are also softened as a whole by heat, the relationship t≧ _t1 between the thicknesses of the heat-fusible coating layer 11 and the heat-fusible film 10 does not collapse, and the bonding durability is maintained. , properties such as thermal conductivity are ensured. The heat insulating mat 8 has a low density and a hardness that allows the heating wire 3 and the temperature detection wire 4 to be buried easily, and the coefficient of thermal expansion of the three can be designed to be the same, and a planar heating device with excellent flexibility can be obtained. . Furthermore, the heater unit 9, which has been arranged and fixed in a meandering manner in advance, can be automatically manufactured, and can be obtained by interposing the heater unit 9 between the surface material 7 and the heat insulating mat 8 and bonding the three by thermocompression. Because of this structure, it is excellent in terms of workability. Effects of the Invention As detailed above, the configuration and operation of the planar heating device of the present invention has the following effects and has great industrial utility value. (1) Excellent heat conduction to the surface material and no local overheating. (2) Temperature detection performance can be improved. (3) It can be folded, making it easy to carry and store. (4) There is no need to worry about crushing or breaking the heating wire or temperature detection wire, and appearance defects such as unevenness of the surface material can be eliminated. (5) Since it can be automated and mass-produced, a low-cost planar heating device can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of the main part showing one embodiment of the planar heating device of the present invention, Figs. 2 and 3 are structural diagrams of the heating wire and temperature detection wire used in the present invention, and Fig. 4 is FIG. 5 is a sectional view of the main part of the heater unit used in the present invention, FIG. 5 is a characteristic diagram of the thickness and adhesive strength of the heat-adhesive film, and FIG. 6 is a sectional view of the main part of a conventional planar heating device. 3... Heat generating wire, 4... Temperature detection wire, 7... Surface material, 8... Insulating mat, 9... Heater unit,
10... Heat-fusible film, 11... Heat-fusible coating layer.

Claims (1)

[Scope of utility model registration request] A heat-fusible coating layer 11 formed by extrusion coating is applied to the outer periphery of the vinyl chloride-coated heating wire 3 and temperature detection wire 4, and the heat-fusible coating layer 11 is applied to the heat-fusible film 10. A heater unit 9 is formed by heat-sealing the heater unit 9, and the heater unit 9 is interposed between a low-density heat insulating mat 8 whose upper surface is flat and the surface material 7, and the heater unit 9 is integrated by thermocompression bonding. This heating device is characterized in that the thickness t of the heat-fusible coating layer 11 covering the heating wire 3 and the temperature detection wire 4 is greater than or equal to the thickness t ₁ of the heat-fusible film 10. Planar heating device.