Electric wires, heaters and car seat heaters

Abstract

The electric wire (1) of the present invention includes a stranded wire (10) in which a plurality of wires (11) are stranded together, and an insulating layer (20) that covers the stranded wire (10), in which Y / X is 10 to 100, where the outer diameter of the stranded wire (10) is X mm and the twist pitch of the stranded wire (10) is Y mm.

Description

[Technical field]

[0001] The present invention relates to an electric wire, a heater, and a heater for a car seat. [Background technology]

[0002] An electric wire is known in which stranded wires are twisted together and the stranded wire is covered with an insulating layer. Such an electric wire can be used, for example, as an electric wire for vehicles. Patent Document 1 discloses an electric wire for vehicles having the above-mentioned configuration. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2019 / 026365 Summary of the Invention [Problem to be solved by the invention]

[0004] The above-mentioned electric wires may be subjected to terminal processing in which the insulation layer at the terminal is stripped off to expose the stranded wires that are the conductors. If the adhesion between the stranded wires and the insulation layer is too high during such terminal processing, the surface of the stranded wire (the surface of the element wires) may peel off together with the insulation layer, causing damage to the stranded wire.

[0005] As a technique for reducing the adhesion between the stranded wire and the insulating layer, a lubricant is filled between the stranded wire and the insulating layer to improve the slipperiness and reduce the adhesion, but using such a technique increases the outer diameter of the wire according to the amount of lubricant filled.

[0006] An object of the present invention is to provide an electric wire capable of reducing the adhesion between a stranded wire and an insulating layer without using a lubricant, a heater having said electric wire, and a car seat heater having said heater. [Means for solving the problem]

[0007] In order to solve the above problem, according to one aspect of the present invention, a stranded wire in which a plurality of wires are stranded together; an insulating layer covering the stranded wire; having The electric wire is provided, characterized in that, when the outer diameter of the stranded wire is X mm and the strand pitch of the stranded wire is Y mm, Y / X is 10-100.

[0008] According to another aspect of the present invention, There is provided a heater comprising the above-mentioned electric wire used as a heating wire.

[0009] According to another aspect of the present invention, There is provided a car seat heater comprising the above heater. Effect of the Invention

[0010] According to the present invention, it is possible to provide an electric wire that can reduce the adhesion between a stranded wire and an insulating layer without using a lubricant, a heater having the electric wire, and a car seat heater having the heater. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1A is a cross-sectional view of an electric wire, and FIG. 1B is a side view of a strand of the electric wire. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, a stranded wire according to a preferred embodiment of the present invention will be described, but the present invention is not limited to the embodiment. In this specification, with respect to the description of "to" indicating a numerical range, the lower limit value and the upper limit value are included in the numerical range.

[0013] [Wire configuration] Fig. 1A is a schematic cross-sectional view of an electric wire 1 according to one embodiment of the present invention, and Fig. 1B is a schematic side view of a stranded wire 10 included in the electric wire 1. As shown in Figs. 1A and 1B, the electric wire 1 has a stranded wire 10 in which a plurality of elemental wires 11 are twisted together, and an insulating layer 20 that covers the stranded wire 10. The outer diameter of the electric wire 1 is, for example, about 0.4 to 2 mm.

[0014] In the twisted wire 10 of the electric wire 1, when the outer diameter of the twisted wire 10 is X mm and the twist pitch of the twisted wire 10 is Y, Y / X is in the range of 10-100. If Y / X is 10 or less, the extension direction (spiral direction) of the wires 11 will be significantly tilted with respect to the longitudinal direction of the electric wire 1, and the degree of adhesion will increase. Conversely, if Y / X is 100 or more, the inclination of the extension direction of the wires 11 will be smaller, and the degree of adhesion will decrease.

[0015] Specifically, when Y / X is 10 or more, the adhesion between the twisted wires 10 and the insulating layer 20 in the electric wire 1 is not too great, and damage to the twisted wires 10 during terminal processing can be suppressed. In other words, when Y / X is 10 or more, the contact area between the twisted wires 10 and the insulating layer 20 per length of the electric wire 1 is not too large, and it is considered that the degree of adhesion can be suppressed. From this viewpoint, Y / X is preferably 15 or more.

[0016] On the other hand, when Y / X is 100 or less, the contact load between the wires 11 in the twisted wire 10 is not too small, and the twisted wire 10 can be prevented from coming out of the insulating layer 20 during terminal processing. In other words, when Y / X is 100 or less, the contact area between the twisted wire 10 and the insulating layer 20 per length of the electric wire 1 is not too small, and it is considered that the degree of adhesion can be maintained. From this viewpoint, Y / X is preferably 80 or less, and more preferably 50 or less. The relationship between Y / X and terminal processability will be described in detail later with examples. The contact load between the twisted wire 10 and the insulating layer 20 is preferably 0.5 to 20 N. If the contact load is 0.5 N or less, the twisted wire 10 will come out of the insulating layer 20 during terminal processing. Also, if the contact load is 20 N or more, a strong force is required when peeling off the insulating layer 20 due to the high adhesion, and there is a risk that the wire stripper will come into contact with and damage the twisted wire 10.

[0017] In addition, as shown in FIG. 1B, focusing on one of the multiple strands 11 twisted into a spiral shape (stripe wire 11 in FIG. 1B), tracing this strand 11, the strand 11 is the axial length of the strand 10 when it makes one revolution (360° rotation) around the central axis (spiral axis) of the strand 10.

[0018] On the other hand, the outer diameter X of the stranded wire was directly measured using a micrometer or a video microscope, or was calculated from the outer diameter of the strands 11 and their number (outer diameter=1.155×outer diameter of strands 11×√number of strands).

[0019] The stranded wires 10 and the insulating layer 20 of the electric wire 1 will be described in detail below.

[0020] (Twisted wire) The stranded wire 10 is formed by stranding a plurality of elemental wires 11 as described above. There is no particular limit to the number of elemental wires 11 that the stranded wire 10 has. The number of elemental wires 11 that the stranded wire 10 has is, for example, about 5 to 40. There is no particular limit to the strand pitch Y and the outer diameter X of the stranded wire 10 as long as the above Y / X is satisfied. The strand pitch Y of the stranded wire 10 is, for example, about 2 to 60 mm. On the other hand, the outer diameter X of the stranded wire 10 is, for example, about 0.1 to 0.6 mm. There is no particular limit to the conductor resistance of the stranded wire 10.

[0021] 1A, wire 11 has conductor 11a and coating 11b coating conductor 11a. In the present embodiment, wire 11 is an enameled wire, conductor 11a is an enameled wire conductor, and coating 11b is an enamel coating. Wire 11 has an outer diameter of, for example, about 0.03 mm to 0.08 mm.

[0022] The conductor 11a is not particularly limited as long as it has electrical conductivity. Examples of the material of the conductor 11a include metals and metal alloys. Examples of the metals and metal alloys include Cu, Ag, and Cu-Ag alloys. In this embodiment, the material of the conductor 11a is a Cu-Ag alloy, and the strand 11 is a Cu-Ag alloy strand with a coating 11b formed on the surface of the Cu-Ag alloy wire. The Cu content and Ag content of the Cu-Ag alloy are not particularly limited. In this embodiment, the Cu-Ag alloy contains, for example, 2 to 11 mass % Ag, with the balance being Cu and unavoidable impurities.

[0023] When the wire 11 is an enameled wire, the enamel coating may be an insulating coating formed by applying and baking a known varnish to the conductor 11a. Examples of the varnish that constitutes the insulating coating include polyvinyl acetal (e.g., polyvinyl formal, polyvinyl butyral, etc.), polyurethane, nylon, polyester, epoxy resin, polyesterimide, polyamide, polyimide, polyamideimide, etc.

[0024] (insulating layer) The insulating layer 20 is not particularly limited as long as it can insulate the stranded wire 10. Examples of materials for the insulating layer 20 include resins and the like. More specifically, examples of materials for the insulating layer 20 include fluororesins, olefin resins, nylon resins, silicones, and the like. More specifically, examples of resins include ETFE, FEP, PFA, polyamide, polypropylene, polyethylene, polyvinyl chloride, and the like.

[0025] The thickness of the insulating layer 20 is not particularly limited as long as it can exhibit the desired insulating function. When the electric wire 1 is used as a heating wire, the thickness of the insulating layer 20 is preferably a thickness that easily transmits heat. The thickness of the insulating layer 20 may be, for example, about 0.05 to 0.2 mm. The insulating layer 20 can be formed by extruding a material for forming the insulating layer 20 around the stranded wire 10.

[0026] (effect) In the electric wire 1 according to the embodiment of the present invention, the adhesion between the twisted wires 10 and the insulating layer 20 is reduced. Therefore, damage to the twisted wires 10 during terminal processing of the electric wire 1 is suppressed. In addition, the adhesion between the twisted wires 10 and the insulating layer 20 is also suppressed from being too low. Therefore, the twisted wires 10 are suppressed from coming loose during terminal processing of the electric wire 1, making terminal processing easier.

[0027] Moreover, with the electric wire 1 according to this embodiment, the adhesion between the stranded wires 10 and the insulating layer 20 can be reduced without using a lubricant. Therefore, the adhesion can be reduced without increasing the outer diameter of the electric wire 1. Furthermore, with the electric wire 1 according to this embodiment, even if a force is repeatedly applied from the outside, the friction between the stranded wires 10 and the insulating layer 20 is small, so that the stranded wires 10 are unlikely to be damaged. Therefore, when the electric wire 1 is used as a heating wire for a heater, damage such as breakage of the stranded wires 10 is suppressed even if a force is applied from the outside. For example, the electric wire 1 according to this embodiment is suitable for a heating wire that is repeatedly subjected to a load, such as a heater for a car seat. EXAMPLES

[0028] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples.

[0029] Electric wires of Samples 1 to 160 were manufactured. First, the manufacturing method and evaluation of the electric wire of Sample 1 will be described below. Next, for the electric wires of Samples 2 to 160, only the manufacturing method and evaluation that are different from those of the electric wire of Sample 1 will be described. The parameters and evaluation results of each sample are shown in Tables 1 to 9.

[0030] (Manufacturing of electric wire for sample 1) A Cu-based alloy cast rod containing 3% Ag by mass with the remainder being Cu and unavoidable impurities, and a wire cold-worked to the middle were subjected to heat treatment, and then cold-worked to 0.05 mm to produce a Cu-Ag alloy wire. The obtained Cu-Ag alloy wire was varnished and baked to enamel-coat the Cu-Ag alloy wire, and eleven Cu-Ag alloy wires with a diameter of 0.06 mm were prepared. The eleven prepared wires were twisted together to obtain a twist pitch of 1.3 mm. The outer diameter of the obtained twisted wire was measured and found to be 0.26 mm. That is, the Y / X ratio of the twisted wire of sample 1 was 5.0.

[0031] An insulating layer having a thickness of 0.1 mm was formed around the stranded wire by extrusion molding of ETFE resin. The outer diameter of the obtained electric wire was 0.46 mm.

[0032] (Evaluation of Sample 1 Wire) <Contact load> The adhesion between the twisted wire and the insulating layer was examined. The adhesion was tested according to strip force in section 5.9 of ISO6722-2. Specifically, a sample was prepared by cutting the electric wire of sample 1 to 75 mm, and 25 mm of the insulating layer on one side of the sample was peeled off. A tensile tester equipped with a jig having a hole that was equal to or larger than the outer diameter of the twisted wire but smaller than the outer diameter of the electric wire was prepared. A part of the insulating layer was peeled off, and the exposed twisted wire was inserted into the hole of the jig, and the electric wire was placed in the tensile tester. The jig was pulled at 250 mm / min to measure the adhesion load between the twisted wire and the insulating layer.

[0033] <Peeling of insulating layer> The wires were terminated with a wire stripper to remove the insulating layer. The peelability of the insulating layer was evaluated according to the following criteria. ○: No damage to the wire coating or conductor ×: Damage to the conductor of the wire

[0034] <Whether or not there is a missing strand> When the above-mentioned terminal processing was performed, whether or not the stranded wire came out of the insulating layer was evaluated according to the following criteria. ○: No loosening of the strands ×: Stranded wire is missing

[0035] <comprehensive evaluation> Based on the above-mentioned peeling property of the insulating layer and the presence or absence of loosened wire strands, the electric wires were comprehensively evaluated as follows. ◯: Both the peelability of the insulating layer and the presence or absence of stranded wires were ◯. x: Either the peeling of the insulating layer or the presence or absence of stranded wires was x.

[0036] (Production and evaluation of electric wires of samples 2 to 160) Electric wires of Samples 2 to 160 were produced in the same manner as the electric wire of Sample 1 except that the conditions were changed as shown in Tables 1 to 9, and evaluated.

[0037] [Table 1]

[0038] [Table 2]

[0039] [Table 3]

[0040] [Table 4]

[0041] [Table 5]

[0042] [Table 6]

[0043] [Table 7]

[0044] [Table 8]

[0045] [Table 9]

[0046] As shown in Tables 1 to 9, samples with Y / X between 10 and 100 were given good overall evaluations. This is believed to be because, with a Y / X ratio of 10 or more, the adhesion between the twisted wire and the insulating layer was not too strong, and the twisted wire was not damaged when the insulating layer was peeled off. On the other hand, with a Y / X ratio of 100 or less, the contact area between the twisted wire and the insulating layer per length of the wire was not too small, and the degree of adhesion could be maintained, so that the twisted wire did not come loose during terminal processing. [Industrial Applicability]

[0047] According to the present invention, it is possible to provide an electric wire that is easy to process the terminal. [Explanation of symbols]

[0048] 1 electric wire 10 strands 11 Wire 11a Conductor 11b Membrane 20 Insulating layer

Claims

1. An electric wire used as a heating wire, a stranded wire in which a plurality of wires are stranded together; an insulating layer covering the stranded wire; having The electric wire, wherein when the outer diameter of the stranded wire is X mm and the strand pitch of the stranded wire is Y mm, Y / X is 10 to 100.

2. 2. The electric wire according to claim 1, wherein the Y / X ratio is 10 to 50.

3. 2. The electric wire according to claim 1, wherein a contact load between the stranded wire and the insulating layer is 0.5 to 20 N.

4. 2. The electric wire according to claim 1, wherein the wire is a Cu-Ag alloy wire.

5. A heater comprising the electric wire according to claim 1 as a heating wire.

6. A heater for a car seat, comprising the heater according to claim 5.

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