JP7437236B2 - Highly flexible heater wire and heating element - Google Patents

Description

The present invention relates to a highly flexible heater wire and a heating element, and more particularly to a heater wire that is used in automobiles and the like and has high bending durability and high wireability, and a heating element equipped with the heater wire.

Heater wires are used as heat sources in heating products such as electric carpets and electric blankets, and vehicle heating members such as seat heaters and steering wheel heaters, and forms have been proposed to suit each application. As heater wires for automobile seats, for example, Patent Document 1 proposes a heating wire that is strong in tensile strength and bending.Specifically, a) a heating element is constructed by twisting a plurality of heating element wires together. and an insulating outer sheath is provided on the heating element, b) a ribbon-shaped heating element wire wound spirally around a core made of polyester, etc., and an insulating outer sheath is provided on the core, and c) multiple wires. A heating element consisting of twisted heating element wires is wound spirally around a core made of polyester, etc., and an insulating outer sheath is provided on the core. d) Consisting of one or more heating element wires coated with insulation. The heating element is spirally wound around a core made of polyester or the like, and an insulating outer skin is provided on the core.

When a heater wire is attached to a car seat, it has been reported that the heater wire gives a feeling of being a foreign body when sitting on the seat, or that it bulges out on the surface of the seat, so it is necessary to make the heater wire more flexible and pliable. there were. In response to this demand, it has been proposed to make the pad material thicker so as not to give the impression of a foreign body, and to attach the heating element through the pad material. However, the padding material acts as a heat insulating material and may impede the ability to quickly heat up the surface of the seat.Conversely, if you want to improve the heating ability, it is necessary to increase the power consumption of the heating element, which increases the power consumption of the heating element. Restrictions arose due to battery capacity, etc.

In response to these problems, for example, Patent Document 2 proposes a heating element using a heating wire that provides excellent seating comfort and is highly durable and reliable. In this heating element, the heating wires arranged on a flexible support are made up of multiple strands of silver-containing copper alloy wire reinforced with metal fibers, which are individually coated with insulation. In addition, the outside of the heating wire is not coated. As a result, the small outer diameter eliminates any discomfort when sitting, and the use of individually insulated wires reinforced with metal fibers improves durability and reliability. .

Japanese Unexamined Patent Publication No. 61-47087 Japanese Patent Application Publication No. 2007-134341

BACKGROUND ART In recent years, heater wires used for automobile seats, etc., are required to be wired with a narrow pitch in order to respond to instant heating (quick heating), and therefore, are required to have a smaller diameter. A heater wire with a small outer diameter has good heat conduction, which improves heating speed and reduces discomfort when seated.

These heater wires must be designed to the required resistance value. The resistance value is adjusted. However, if the horizontal winding density of the heating wires is not appropriate and a gap is created between the heating wires, when the insulating jacket is pushed out, the insulating jacket falls into the gap and a recess is generated, resulting in a poor appearance. As a result, bending starting from the concave portion may occur at an unintended location, which may reduce workability or bending durability. In particular, heater wires for automobile seats are wired on non-woven fabric at a narrow pitch, so if there are recesses in the exterior, there is a risk that they may get caught in the wiring equipment, reducing workability or causing wire breakage. . In addition, if the heating wire is wound too tightly and the heating wire is raised, resulting in a convex appearance, bending starting from the convexity may occur in unintended areas, reducing workability and bending durability. There is a risk that it may cause

The present invention has been made in order to solve the above problems, and its purpose is to provide a heater wire for use in automobiles, etc., which can realize a reduction in diameter, has high bending durability, and high wireability, and the same. An object of the present invention is to provide a heating element equipped with a heating element.

The heater wire according to the present invention includes a fiber core, a heat generating portion formed by winding a plurality of heat generating wires spirally around the outer periphery of the fiber core, and an insulating jacket provided around the outer periphery of the heat generating portion. , characterized in that the horizontal winding density of the heating wire is within a range of 70% or more and 98% or less.

According to this invention, since the horizontal winding density of the heating wires is within the above range, the gaps between the heating wires are small, and when the insulation jacket is pushed out, the insulation jacket falls into the gap and forms a recess. This suppresses the occurrence of bumps and raised protrusions. As a result, the appearance is not deteriorated, bending based on the unevenness does not occur, and it is possible to have excellent workability and bending durability. Particularly in the case of heater wires for automobile seats, even if the wires are wired in a nonwoven fabric at a narrow pitch, there is no risk of the wires getting caught in wiring equipment and causing disconnection.

In the heater wire according to the present invention, the heating wire is horizontally wound in a single layer at a pitch of 0.2 to 50 times the outer diameter D1 of the fiber core.

In the heater wire according to the present invention, the number of the heating wires is within a range of 1 to 10.

In the heater wire according to the present invention, the heating wire is a metal wire or a baked wire with an insulating coating provided on the metal wire.

A heating element according to the present invention is characterized in that the heater wire according to the present invention described above is attached thereto.

According to the present invention, it is possible to provide a heater wire that is used in automobiles and the like and has a reduced diameter, high bending durability, and high wiring performance, and a heating element equipped with the heater wire.

FIG. 2 is a schematic explanatory diagram showing an example of a heater wire according to the present invention. It is an explanatory view explaining horizontal winding density of a heating wire. (A) is the appearance of the insulating jacket within the preferred horizontal winding density range, (B) is the appearance of the insulating jacket when the horizontal winding density is less than the specified range, and (C) is the appearance of the insulating jacket when the horizontal winding density is less than the specified range. This is the appearance of the insulation jacket when the specified range is exceeded. It is an explanatory view of a heating line. FIG. 3 is an explanatory diagram showing an aspect of a bending test.

Hereinafter, a heater wire and a heating element according to the present invention will be explained with reference to the drawings. Note that the present invention is not limited to the illustrated embodiment.

[Heater wire]
As shown in FIGS. 1 and 2, the heater wire 10 according to the present invention includes a fiber core 1, a heat generating portion formed by spirally winding a plurality of heat generating wires 2 provided around the outer periphery of the fiber core 1, It has an insulating jacket 3 provided around the outer periphery of the heat generating part. A feature is that the horizontal winding density of the heating wire 2 is within a range of 70% or more and 98% or less. Note that "having" means that other configurations may be included as long as the effects of the present invention are not impaired, such as plating (not shown) or insulation on the surface of the metal wire 2a. This means that a coating 2b may be provided or a fusion layer or the like may be provided on the outer periphery of the insulating jacket 3.

In this heater wire 10, since the horizontal winding density of the heating wire 2 is within the above range, the gap G between the heating wires is small, and when the insulating jacket 3 is extruded, the horizontal winding density of the heating wire 2 is within the above range. In this way, the insulating jacket 3 is prevented from falling into the gap G and forming a recess 5a or a raised protrusion 5b. As a result, the appearance is not deteriorated, bending starting from the unevenness 5 does not occur, and it is possible to have excellent workability and bending durability. Particularly in the case of heater wires for automobile seats, even if the wires are wired in a nonwoven fabric at a narrow pitch, there is no risk of the wires getting caught in wiring equipment and causing disconnection. In addition, as shown in FIG. 3, "horizontal winding density" means, at a predetermined length L, the wire diameter (mm) of the heating wire 2 is D2, and the gap G1 between the heating wire 2 and the adjacent heating wire 2,... When the average of Gn (mm) is G (mm), it is expressed as [D2/(D2+G)]×100(%).

Each component of the heater wire will be explained in detail below.

(fiber core)
The fiber core 1 is an essential component located as a core material in the center when the heater wire 10 is viewed in cross section, and is preferably a high tensile strength body that functions as a winding core. The center when viewed in cross section is a position where the center position of the fiber core 1 and the center position of the cross section of the heater wire 10 coincide or almost coincide with each other when viewed in cross section. As an example of the fiber core 1, a fiber yarn made by bundling a plurality of fibers is preferably used. It is preferable that the fibers constituting the fiber thread have strength and are heat resistant. Examples of fibers include polyester fibers such as Tetron (registered trademark), wholly aromatic polyamide fibers such as Kevlar (registered trademark), polyarylate fibers such as Vectran (registered trademark), and glass fibers. Further, the fiber core 1 may be formed by arbitrarily composing fibers made of different materials or fiber threads having different outer diameters.

The fiber core 1 has a concentric (perfect circular) or substantially concentric cross section made of fiber yarns made of assembled lines, twisted lines, or braided lines. At this time, in order to make the fiber core 1 have a concentric or substantially concentric cross section, it is more preferable that the fiber threads are twisted wires. The outer diameter D1 of the fiber core 1 is not particularly limited, but may be in the range of 0.1 to 1.0 mm, for example. Since the fiber core 1 made of fiber yarn is flexible and easily deformed, the outer diameter D1 of the fiber core 1 is the outer diameter when the fiber core 1 is a perfect circle, and the outer diameter D1 when the fiber core 1 is flat. The cross-sectional area is evaluated as the outer diameter converted to the cross-sectional area of a perfect circle.

The fiber core 1 is usually expressed in fineness (dtex), which indicates the weight of fiber yarn, and 1 dtex is 1 g at a length of 10,000 m. The dtex range of the fiber core 1 is preferably 110 to 2000 dtex. The fiber core 1 may be made of a single fiber thread or may be made of two or more types of fiber threads. When the fiber core 1 is composed of two or more types of fiber threads, the total dtex may be within the above range. If it is less than 110 dtex, durability tends to be insufficient. On the other hand, if it exceeds 2000 dtex, the outer diameter becomes large, which tends to affect workability and processability.

(heat generating part)
The heat generating part is an essential component formed by winding a plurality of heat generating wires 2 spirally around the outer periphery of the fiber core 1. The heating wire 2 is a resistance wire that generates heat due to electric current, and the resistance wire and the number thereof that have a predetermined resistance value can be arbitrarily selected and used depending on the heating specifications. Helically wound means, for example, as in the example described later, six heating wires 2 are simultaneously wound spirally, so that every six heating wires are wound in a single layer. Note that, in order to prevent the final outer diameter of the heater wire 10 from increasing, the heater wire 10 is usually made of a single layer, but may be made of two layers.

The heating wire 2 is configured using a plurality of resistance wires each having a diameter D2 of 0.04 mm or more and 0.2 mm or less. By spirally winding the thin heating wire 2, the diameter can be reduced, and the entire heater wire can be made smaller in diameter, lighter, and more flexible. A plurality of wires refers to the range of the number of wires that can be spirally wound as shown in FIG. 1, and in the examples described later, it is set to 6 or 7 wires, but for example, 1 to 10 wires is preferably mentioned. It should be noted that the pitch when winding the fiber core 1 in a spiral manner varies depending on the diameter of the fiber core 1 and the number and diameter of the heating wires 2, so it cannot be stated unconditionally. It is preferable that a single layer is horizontally wound at a pitch.

The heating wire 2 has a horizontal winding density of 70% or more and 98% or less. By setting the horizontal winding density in this range, the gap G between the heating wires becomes small, and when the insulation jacket 3 is pushed out, the insulation jacket 3 falls into the gap G as shown in FIG. The occurrence of recesses 5a (see FIG. 3(B)) and raised protrusions 5b (see FIG. 3(C)) is suppressed. As a result, the appearance does not deteriorate, bending starting from the unevenness 5 (5a, 5b) does not occur, and it is possible to obtain excellent workability and bending durability. Particularly in the case of heater wires for automobile seats, even if the wires are wired in a nonwoven fabric at a narrow pitch, there is no risk of the wires getting caught in wiring equipment and causing disconnection. When the horizontal winding density is less than 70%, when the insulating outer sheath 3 is extruded, the insulating outer sheath 3 falls into the gap G between the heating wires 2, and a recess 5a is generated on the surface of the insulating outer sheath 3. . On the other hand, if the horizontal winding density exceeds 98%, the heating wire 2 may float, and a convex portion 5b may be formed on the surface of the insulating jacket 3. In addition, the more preferable range of horizontal winding density is within the range of 85% or more and 95% or less.

"Horizontal winding density" means, as shown in FIG. 3, at a predetermined length L, the wire diameter (mm) of the heating wire 2 is D2, and the gap G1,..., Gn( When G is the average of mm), it is expressed as [D2/(D2+G)]×100(%). When the heating wires are tightly wound in a single layer, the gap G is 0, so the value is 100%. For example, when the gap G corresponding to 1/4 of D2 is generated, the value is 80%. The "predetermined length L" is the length for calculating the horizontal winding density by substituting the average value of the gap G into the equation. For example, the predetermined length is 10 times the wire diameter D2 of the heating wire 2. The distance is calculated using the average G of the gaps G1, . . . , Gn over that length. The length L is not particularly limited, and does not need to be 10 times the wire diameter D2 of the heating wire 2, and when taking the average of the five gaps G1,..., G5, it is five times the wire diameter D2. In the case of taking the average of 20 gaps G1, . . . , G20, it may be 20 times the wire diameter D2.

The heating wire 2 may be made of only a metal wire 2a as shown in FIG. 4(A), or a baked wire with an insulating coating 2b provided on the metal wire 2a as shown in FIG. 4(B). I can list some things. Examples of the metal wire 2a include copper wire and copper alloy wire. Examples of the copper alloy wire include CuAg alloy, CuSn alloy, CuNi alloy, and the like. A plating layer may be applied to the surface of the metal wire 2a. As the plating layer, a solder plating layer, a tin plating layer, a gold plating layer, a silver plating layer, a nickel plating layer, etc. are preferable. Examples of the insulating coating 2b include heat-resistant polyurethane (PU), polyesterimide (PEI), polyimide (PI), polyamideimide (PAI), and the like. The thickness of the insulating coating 2b is classified into Type 1, Type 2, and Type 3 in general Japanese Industrial Standards (JIS C 3202:2014), and any thickness can be selected from among them.

(Insulating jacket)
The insulating jacket 3 is provided to cover the heating wire 2. For example, after providing the heating wire 2, it can be formed by resin extrusion or the like so as to cover the outer periphery thereof. The material for forming the insulating jacket 3 may be any insulating and heat-resistant resin material, but in the present invention, the insulating jacket 3 is made of a fluorine-based material such as nylon, polyester elastomer, ETFE, FEP, or PFA. Preferred examples include resins. It may also be a vinyl chloride resin, a polyolefin such as polyethylene, or a polyester such as polyethylene terephthalate.

The thickness of the insulating jacket 3 may be approximately 0.05 to 1.0 mm, but from the perspective of reducing the diameter, the thinner the better, while the thicker the better for bending durability. Taking these into consideration, extrusion coating with a thickness of 0.10 to 0.30 mm is preferable.

The insulating jacket 3 is preferably formed by resin extrusion. The insulating jacket 3 after being extruded tends to have a constant thickness, and its surface can also have small irregularities. By providing such an extruded insulating jacket 3 as the outermost layer, local bending is less likely to occur even when the diameter is reduced for narrow pitch wiring. As a result, the diameter can be reduced to such an extent that no discomfort is felt when sitting, and narrow pitch wiring can be performed when used as a heat generating element, and the bending durability can be improved.

[Heating element]
The heating element according to the present invention is equipped with the heater wire 10 according to the present invention. Since such a heating element is formed using a heater wire 10 that can achieve bending durability, it is easy to sew the heater wire 10 to an object such as a sheet base material that constitutes the heating element with good wiring. become.

Examples of the heating element include those used for various purposes, such as heating products such as electric carpets and electric blankets, and vehicle heating members such as seat heaters and steering heaters, preferably for automobiles. It can be attached to a seat for use. In a heating element used as a heating member for an automobile, a heater wire is sewn into an object such as a seat base material.

When sewing the heater wire 10 onto the sheet base material, if the surface of the heater wire 10 is uniform and there are no irregularities 5, stress concentration will be less likely to occur and bending durability will be improved, so sewing can be performed with good wiring. Stress is applied to the heater wire 10 when wiring and sewing the heater wire 10, but since the heater wire 10 according to the present invention has high resistance to such stress, the diameter can be reduced to such a degree that it does not make you feel uncomfortable when sitting on it. In addition, narrow pitch wiring is also possible when used as a heating element.

Hereinafter, the present invention will be explained in more detail with reference to Examples. Note that the present invention is not limited thereby.

[Example 1]
As the fiber core 1, a bundle of polyarylate fibers having an outer diameter of about 0.27 mm was used. On this fiber core 1, a metal wire 2a made of a copper alloy wire (copper alloy containing 0.3% by mass of tin) with an outer diameter of 0.120 mm is applied. .) Seven wires were used as heating wires 2, and the seven wires were simultaneously wound horizontally in a spiral shape at a pitch of 2.4 mm so as to form a single layer. Next, the insulating jacket 3 was formed by melt-extruding nylon 12 to a thickness of 0.2 mm. In this way, a heater wire 10 having a total outer diameter of 0.90 mm was produced. The horizontal winding density at this time was 85.5%.

[Example 2]
As the fiber core 1, a bundle of polyarylate fibers having an outer diameter of about 0.17 mm was used. On this fiber core 1, six copper alloy wires having an outer diameter of 0.09 mm were used as heating wires 2, and the six wires were simultaneously wound horizontally in a spiral shape at a pitch of 2.0 mm so as to form a single layer. Next, the insulating jacket 3 was formed by melt-extruding the same nylon 12 as described above to a thickness of 0.27 mm. In this way, a heater wire 10 having a total outer diameter of 0.90 mm was produced. The horizontal winding density at this time was 80.3%.

[Example 3]
As the fiber core 1, a bundle of polyarylate fibers having an outer diameter of about 0.27 mm was used. On this fiber core 1, seven copper alloy wires having an outer diameter of 0.080 mm were used as heating wires 2, and the seven wires were wound spirally horizontally at a pitch of 1.67 mm so as to form a single layer at the same time. Next, the insulating jacket 3 was formed by melt-extruding the same nylon 12 as described above to a thickness of 0.23 mm. In this way, a heater wire 10 having a total outer diameter of 0.90 mm was produced. The horizontal winding density at this time was 72.8%.

[Example 4]
As the fiber core 1, a bundle of polyarylate fibers having an outer diameter of about 0.17 mm was used. On this fiber core 1, six copper alloy wires having an outer diameter of 0.080 mm were used as heating wires 2, and the six wires were simultaneously wound horizontally in a spiral shape at a pitch of 0.91 mm so as to form a single layer. Next, the insulating jacket 3 was formed by melt-extruding the same nylon 12 as described above to a thickness of 0.28 mm. In this way, a heater wire 10 having a total outer diameter of 0.90 mm was produced. The horizontal winding density at this time was 93.6%.

[Comparative example 1]
As the fiber core 1, a bundle of polyarylate fibers having an outer diameter of about 0.27 mm was used. On this fiber core 1, seven copper alloy wires having an outer diameter of 0.074 mm were used as heating wires 2, and the five wires were wound spirally horizontally at a pitch of 3.51 mm so as to form a single layer at the same time. Next, the insulating jacket 3 was formed by melt-extruding the same nylon 12 as described above to a thickness of 0.24 mm. In this way, a heater wire 10 having a total outer diameter of 0.90 mm was produced. The horizontal winding density at this time was 60.0%.

[Characteristics evaluation]
Each heater wire 10 was passed through an unevenness detector to evaluate the surface condition. The unevenness detector was set to be able to detect unevenness of 50 μm or more. The evaluation was performed based on the number of recesses in a length of 10 m, and the case where there were less than 3 recesses was evaluated as "○", and the case where there were 3 or more recesses was evaluated as "▲". In Examples 1 to 4, the horizontal winding density was within a preferable range of 72.8% to 93.6%.

In the bending durability test, as shown in FIG. A load 41 was attached, and the number of bends was measured in a direction perpendicular to the mandrel 42 at a rate of 30 times per minute, with one bend being 90 degrees on each side. The number of bending times was evaluated as the number of times until the resistance value of the heater wire 10 increased by 10%. Since all of the heater wires 10 subjected to the test were bent over 5,000 times, the evaluation was given as "○", and the measurement was ended when the bending number was exceeded. On the other hand, in Comparative Example 1, the number of bends did not reach 5,000 times, so the evaluation was given as "△".

1 Fiber core 2 Heat generating wire 2a Metal wire 2b Insulating coating 3 Insulating outer coating 5 Unevenness 5a Recess (gap)
5b Convex part (raised part)
10 Heater wire 41 Load 42 Mandrel 43 Guide D1 Outer diameter of fiber core D2 Wire diameter of heating wire L Predetermined length G Gap

Claims (4)

It has a fiber core, a heat generating part formed by spirally winding a plurality of heat generating wires in a single layer around the outer periphery of the fiber core, and an insulating jacket provided around the outer periphery of the heat generating part, and has a predetermined length. In L, when the wire diameter (mm) of the heating wire is D2 and the average of the gaps G ₁ , . . . , G _n (mm) between the heating wire and the adjacent heating wire is G, [D2/(D2+G)]× A heater wire characterized in that a horizontal winding density of the heating wire expressed as 100(%) is within a range of 72.8% or more and 98% or less. The heater wire according to claim 1, wherein the heating wire is horizontally wound in a single layer at a pitch of 0.2 to 50 times the outer diameter D1 of the fiber core. The heater wire according to any one of claims 1 and 2 , wherein the heating wire is a metal wire or a baked wire with an insulating coating provided on the metal wire. A heating element, characterized in that the heater wire according to any one of claims 1 to 3 is attached thereto.

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