JP2016195077A - Molded wire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a molded wire excellent waterproofness.SOLUTION: According to an embodiment, a molded wire 10 comprises a conductor wire 14, an insulator 15 that coats the periphery of the conductor wire 14 and has a two layer structure composed of an inner layer 15a and an outer layer 15b comprising water-swellable material, and a mold resin molding 13 that directly coats a terminal of the insulator 15.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a molded electric wire.

  2. Description of the Related Art Conventionally, in an electronic component such as a sensor, a molded electric wire is known in which an electronic circuit is connected to a cable end, and the connection portion and the periphery thereof are covered and protected by a molded resin molding (for example, Patent Document 1). reference).

  In these molded electric wires used for automobiles, robots, electronic devices and the like that require high reliability, waterproofness and airtightness between the molded resin molded body and the cable are one of the extremely important characteristics. When water penetrates into the molded resin molded body and reaches the electrode terminal portion of the electronic circuit, the terminal is corroded, and troubles such as failure due to poor conduction occur. For this reason, it is important to use a material having excellent adhesion to the molded resin molded body for the cable sheath.

  In the molded electric wire disclosed in Patent Document 1, the sheath and insulator of the cable end are removed, the exposed conductor wire is connected to the sensor, and the molded resin molding covers the sensor to the end of the sheath. ing. The molded resin molded body is made of polyamide resin or polybutylene terephthalate resin, and the sheath is made of a thermoplastic polyurethane resin composition having high adhesion to these resins.

JP 2007-95439 A

  In the cable disclosed in Patent Document 1, as described above, a thermoplastic polyurethane resin composition having excellent adhesion to a molded resin molded body is used as a sheath material. However, if a gap is generated between the molded resin molding and the sheath due to dimensional variations due to manufacturing errors or repeated heating and cooling, water penetrates into the gap due to capillary action, and molding resin molding There is a risk of water entering the body.

  On the other hand, a molded electric wire having a structure in which a molded resin molded body covers up to an insulator exposed at the end of a cable and does not cover a sheath has been studied. According to such a structure, the mold resin molded body can be reduced in size as compared with the structure in which the mold resin molded body covers up to the sheath, and the bending radius of the cable near the mold resin molded body can be reduced. Thus, the routeability can be improved. In the molded electric wire having a structure in which the molded resin molded body covers up to the insulator exposed at the end of the cable and does not cover the sheath, the molded resin molded body has a structure in which the molded resin molded body covers up to the end of the sheath. However, water easily enters the inside of the molded resin molded body. This is because the contact area when the molded resin molded body covers the insulator is smaller than the contact area when the molded resin molded body covers the sheath, and even when a relatively small gap is generated, This is because an intrusion path is easily formed.

  Then, an object of this invention is to provide the molded electric wire which has the outstanding waterproofness.

  In one embodiment of the present invention, in order to achieve the above object, a conductor wire, an insulating member having a multilayer structure including a water-swellable material in an outermost layer covering an outer periphery of the conductor wire, and an end of the insulating member are provided. There is provided a molded electric wire having a molded resin molded body that is directly covered.

  ADVANTAGE OF THE INVENTION According to this invention, the molded electric wire which has the outstanding waterproofness can be provided.

Fig.1 (a) is a side view of the molded electric wire which concerns on the 1st Embodiment of this invention. FIG. 1B is a side view of the molded electric wire in a state where the molded resin molded body is cut in the length direction of the molded electric wire. FIG. 2 is a radial cross-sectional view of a cable included in the molded electric wire according to the first embodiment of the present invention. FIG. 3 is a side view of a modified example of the molded electric wire according to the first embodiment of the present invention. Fig.4 (a) is a side view of the molded electric wire which concerns on the 2nd Embodiment of this invention. FIG. 4B is a side view of the molded electric wire in a state where the molded resin molded body is cut in the length direction of the molded electric wire. FIG. 5 is a radial cross-sectional view of a cable included in the molded electric wire according to the second embodiment of the present invention. FIG. 6A is an enlarged cross-sectional view of a main part of a sample used for a test according to an example of the present invention. FIG. 6B is a schematic diagram illustrating an implementation state of the airtightness test according to the present example.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, in each figure, about the component which has the substantially same function, the same code | symbol is attached | subjected and the duplicate description is abbreviate | omitted.

[First Embodiment]
(Configuration of molded wire)
Fig.1 (a) is a side view of the molded electric wire 10 which concerns on the 1st Embodiment of this invention. FIG. 1B is a side view of the molded electric wire 10 in a state in which the molded resin molded body 13 is cut in the length direction of the molded electric wire 10.

  The molded electric wire 10 includes a cable 11, an electronic circuit 12 connected to the end of the cable 11, and a molded resin molded body 13 that covers and protects the electronic circuit 12. The electronic circuit 12 is an electronic circuit that constitutes an electronic device such as a sensor.

  FIG. 2 is a cross-sectional view in the radial direction of the cable 11 included in the molded electric wire 10.

  The cable 11 includes a conductor wire 14, an insulator 15 as an insulating member that covers the outer periphery of the conductor wire 14, and a sheath 16 that covers the outer periphery of the insulator 15. The conductor wire 14 and the insulator 15 constitute an insulated wire 18.

  At the end of the cable 11, the sheath 16 is removed and the insulator 15 is exposed. Further, the exposed end of the insulator 15 is removed, and the conductor wire 14 is exposed. The exposed conductor wire 14 is connected to the electrode terminal 17 of the electronic circuit 12.

  The molded resin molded body 13 covers from the electronic circuit 12 to the end of the insulator 15 and does not cover the sheath 16. The molded resin molded body 13 directly covers the insulator 15, and the airtightness inside the molded resin molded body 13 is ensured by the adhesion between the molded resin molded body 13 and the insulator 15.

  The mold resin molded body 13 is formed by injection molding or the like. Polyamide or polybutylene terephthalate is preferably used as the resin constituting the molded resin molded body 13, and glass fibers are more preferably included to increase the strength.

  As the material of the conductor wire 14, a known material such as copper, annealed copper, silver, or aluminum can be used. Moreover, in order to improve heat resistance, the surface of these materials may be subjected to tin plating, nickel plating, silver plating, gold plating, or the like.

  The insulator 15 has a two-layer structure including an inner layer 15a and an outer layer 15b. The insulator 15 is formed by extrusion coating the inner layer 15 a and the outer layer 15 b on the conductor wire 14. As a method of extrusion coating, a known method using an extruder can be used. The inner layer 15a and the outer layer 15b may be formed in separate steps, or may be formed in one step by a two-layer co-extrusion head using two extruders.

  The outer layer 15b is made of a resin or rubber containing a water swellable material, and is excellent in water swellability. For this reason, even when there is a gap due to peeling or cracking between the molded resin molded body 13 and the insulator 15 due to dimensional variations due to manufacturing errors of the molded electric wire 10 or repeated heating and cooling, In the presence of moisture, the outer layer 15b swells and closes the gap, and water can be prevented from entering the molded resin molded body 13.

  On the other hand, the inner layer 15a is made of a resin or rubber that does not contain a water-swellable material. This is because the insulating property of the water-swellable material is lower than that of the resin or rubber that is the material of the inner layer 15a, and the insulating property of the inner layer 15a is reduced by adding the water-swellable material.

  Examples of the water-swellable material contained in the outer layer 15b include polyacrylic acid (salt), polyvinyl alcohol, polyethylene glycol, polyvinyl pyrrolidone, poly (meth) acrylamide, polyurethane, and polyurethane-polyacrylamide IPN (interpenetrating polymer network). Water-absorbing polymer, bentonite (clay mineral), silica gel and other inorganic fillers. In particular, it is preferable to use poly (meth) acrylamide or polyurethane excellent in adhesiveness with polyamide or polybutylene terephthalate used as the material of the molded resin molded body 13.

  The content of the water-swellable material of the outer layer 15b is not particularly limited as long as the water-swellability is exhibited, but from the viewpoint of moldability and cost, it is 0 with respect to 100 parts by weight of the resin or rubber as the base polymer. It is preferable that it is 0.01-50 mass parts.

  As the base polymer of the outer layer 15b and the material of the inner layer 15a, known insulating materials used for insulators of conventional insulated wires can be used. Examples of the insulating material include polypropylene, high density polyethylene, linear low density polyethylene, low density polyethylene, ultra-low density polyethylene, ethylene-butene-1 copolymer, ethylene-hexene-1 copolymer, ethylene- Octene-1 copolymer, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, polybutene, poly-4-methyl-pentene-1, ethylene-butene-hexene terpolymer, ethylene-methyl methacrylate Resins such as copolymers, ethylene-methyl acrylate copolymers, ethylene-glycidyl methacrylate copolymers, ethylene-propylene-diene copolymers, ethylene-propylene copolymers, ethylene-butene-1-diene copolymers , Ethylene-octene-1-diene copolymer, acrylo Tolyl butadiene rubber, acrylic rubber, styrene rubber (for example, styrene-diene copolymer such as styrene butadiene rubber, styrene isoprene rubber, styrene-diene-styrene copolymer such as styrene-butadiene-styrene rubber, styrene-isoprene-styrene rubber) Examples thereof include rubbers such as polymers and rubbers obtained by hydrogenation thereof, and thermoplastic elastomers such as thermoplastic polyurethane, and these can be used alone or in combination of two or more.

  Especially, it is preferable that the base polymer of the outer layer 15b is a thermoplastic polyurethane from an adhesive viewpoint with the mold resin molding 13. As this thermoplastic polyurethane, polyester polyurethane (adipate, caprolactone, polycarbonate) and polyether polyurethane can be used. In particular, it is preferable to use a polyether-based polyurethane from the viewpoint of resistance to heat and moisture.

  In order to impart heat resistance to the outer layer 15b and the inner layer 15a, the base polymer of the outer layer 15b and the material of the inner layer 15a may be cross-linked. As a crosslinking method, organic peroxide crosslinking, electron beam irradiation crosslinking, silane crosslinking, or the like can be used.

  In addition, if necessary, the base polymer of the outer layer 15b and the material of the inner layer 15a may be processed aids, flame retardants, flame retardant aids, crosslinking agents, crosslinking aids, antioxidants, ultraviolet absorbers, copper damage prevention. Additives such as agents, lubricants, inorganic fillers, adhesion-imparting agents, stabilizers, carbon black, and colorants may be added.

  The thickness of the outer layer 15b is not particularly limited as long as it is in a range where water swellability can be exhibited. The thickness of the inner layer 15a is not particularly limited as long as the insulation of the insulator 15 can be sufficiently ensured. The ratio between the thickness of the inner layer 15a and the thickness of the outer layer 15b is not particularly limited. Further, the hardness of the inner layer 15a and the outer layer 15b is not particularly limited.

  The insulator 15 may have a multilayer structure of three or more layers. In this case, the outermost layer of the multilayer structure is made of resin or rubber containing a water-swellable material, like the outer layer 15b.

  The number of insulated wires 18 included in the molded wire 10 may be singular or plural (two in the example shown in FIGS. 1 and 2). When the molded wire 10 has a plurality of insulated wires 18, as shown in FIG. 1, the ends of the plurality of insulated wires 18 are collectively covered with a single molded resin molded body 13.

  As the material of the sheath 16, general materials such as thermoplastic polyurethane and polyolefin resin can be used, and these materials may be cross-linked in order to impart heat resistance and the like.

  As shown in FIG. 3, a corrugated tube 19 may be used instead of the sheath 16. By using the corrugated tube 19, it is possible to improve the impact resistance of the cable 11 while maintaining ease of bending. As a material of the corrugated tube 19, general materials such as polypropylene and polyamide can be used, and it is preferable that these are flame-retardant. FIG. 3 is a side view of the state in which the molded resin molded body 13 is cut in the same manner as FIG.

  Further, instead of the sheath 16, a protective tape may be wound around the outer periphery of the insulator 15.

(Effects of the first embodiment)
According to the molded electric wire 10 according to the first embodiment, since the outermost layer of the insulator 15 has water swellability, there is a gap between the mold resin molded body 13 and the insulator 15. However, in the presence of moisture, the outer layer 15b swells to close the gap, and the waterproofness inside the molded resin molded body 13 can be sufficiently secured.

  Further, since the molded resin molded body 13 does not cover the sheath 16 and covers the end of the insulator 15, the mold-processed electric wire 10 is highly routeable, and the mold resin molded body 13 is downsized. be able to.

[Second Embodiment]
The molded electric wire according to the second embodiment is different from the molded electric wire according to the first embodiment in that the molded resin molded body covers up to the sheath of the cable.

(Configuration of molded wire)
FIG. 4A is a side view of the molded electric wire 20 according to the second embodiment of the present invention. FIG. 4B is a side view of the molded electric wire 20 in a state where the molded resin molded body 13 is cut in the length direction of the molded electric wire 20.

  Similar to the molded wire 10 according to the first embodiment, the molded wire 20 is a cable 21, an electronic circuit 12 connected to the end of the cable 21, and a mold resin that covers and protects the electronic circuit 12. And a molded body 13.

  The molded resin molded body 13 covers the electronic circuit 12 to the end of the sheath 26. The mold resin molded body 13 directly covers the sheath 26, and the airtightness inside the mold resin molded body 13 is ensured by the adhesion between the mold resin molded body 13 and the sheath 26.

  FIG. 5 is a sectional view in the radial direction of the cable 21 included in the molded electric wire 20.

  The sheath 26 as an insulating member according to the present embodiment includes an inner layer 26a that does not include a water-swellable material and a water-swellable material, similarly to the insulator 15 of the molded wire 10 according to the first embodiment. The outer layer 26b has a two-layer structure.

  As the water-swellable material contained in the outer layer 26b, the same water-swellable material as that contained in the outer layer 15b of the insulator 15 according to the first embodiment can be used. As the material of the base polymer of the inner layer 26a and the material of the outer layer 26b, a general material can be used as a sheath material such as thermoplastic polyurethane or polyolefin resin.

  Since the outer layer 26b has water swellability, a gap is generated between the molded resin molded body 13 and the sheath 26 due to dimensional variations caused by manufacturing errors of the molded wire 20 and repeated heating and cooling. However, in the presence of moisture, the outer layer 26 b swells and closes the gap, so that water can be prevented from entering the mold resin molded body 13.

  The sheath 26 may have a multilayer structure of three or more layers. In this case, the outermost layer of the multilayer structure includes a water-swellable material, like the outer layer 26b.

  In the molded electric wire 20, the water swellability of the surface of the sheath 26 ensures the waterproof property inside the molded resin molded body 13, so the insulator 25 does not need to have water repellency. For this reason, the insulator 25 may have a single-layer structure, and the material thereof is not particularly limited, and a conventionally commonly used material such as crosslinked polyethylene can be used.

  The number of insulated wires 28 included in the molded wire 20 may be singular or plural (two in the example shown in FIGS. 4 and 5). When the molded wire 20 has a plurality of insulated wires 28, as shown in FIG. 4, the ends of the plurality of insulated wires 28 are collectively covered with one molded resin molded body 13.

(Effect of the second embodiment)
According to the molded electric wire 20 according to the second embodiment, since the outermost layer of the sheath 26 has water swellability, even when a gap is generated between the molded resin molded body 13 and the insulator 15. In the presence of moisture, the outer layer 26b swells to close the gap, and the waterproofness inside the molded resin molded body 13 can be sufficiently secured.

[Summary of embodiment]
Next, the technical idea grasped from the above-described embodiment will be described with reference to the reference numerals in the embodiment. However, the reference numerals and the like in the following description are not intended to limit the constituent elements in the claims to the members and the like specifically shown in the embodiments.

  [1] A conductor wire (14), an insulating member that covers the outer periphery of the conductor wire (14) and has a multilayer structure including a water-swellable material in the outermost layer, and a mold that directly covers the ends of the insulating member A molded electric wire (10, 20) having a resin molded body (13).

  [2] The molded electric wire (10, 20) according to [1], wherein the water-swellable material is a water-absorbing polymer or an inorganic filler.

  [3] The molded electric wire (10, 20) according to [2], wherein the water-swellable material is poly (meth) acrylamide or polyurethane.

  [4] The molded electric wire (10, 20) according to any one of [1] to [3], wherein the molded resin molded body (13) is made of polyamide or polybutylene terephthalate.

  [5] The molded electric wire (10) according to any one of [1] to [4], wherein the insulating member is an insulator (15) that directly covers an outer periphery of the conductor wire (14). ).

  [6] The molded electric wire (20) according to any one of [1] to [4], wherein the insulating member is a sheath (26) that indirectly covers the outer periphery of the conductor wire (14). .

  [7] A plurality of insulated wires (18) each including the conductor wire (14) and the insulator (15) are provided, and the ends of the plurality of insulated wires (18) are collectively covered with the molded resin molded body (13). The molded electric wire (10) according to [5].

  [8] The mold according to [7], including a sheath (16) that collectively covers the outer circumferences of the plurality of insulated wires (18), wherein the molded resin molded body (13) does not contact the sheath (16). Processed electric wire (10).

  [9] Heat shock test with 100 cycles of standing in water at 25 ° C for 20 minutes, standing in air at -40 ° C for 20 minutes, and standing in air at 120 ° C for 20 minutes The molded electric wire (10, 20) according to any one of the above [1] to [8], wherein the waterproofness inside the molded resin molded body (13) is maintained even if the water is immersed after the execution. .

  Hereinafter, the result of the test for evaluating the waterproof property inside the molded resin molded body 13 of the molded electric wire 10 according to the first embodiment and the molded electric wire 20 according to the second embodiment will be described.

(Configuration of evaluation sample)
FIG. 6A is an enlarged cross-sectional view of the main part of the sample 30 used in the test according to this example. The sample 30 includes a conductor wire 31, an insulator 32 that covers the outer periphery of the conductor wire 31, and a molded resin molded body 33 that covers one end of the insulator 32. The insulator 32 has a two-layer structure of an inner layer 32a and an outer layer 32b.

  The conductor wire 31 is a stranded wire composed of seven copper conductor wires having a diameter of 0.26 mm, and allows air to pass through the conductor wire 31 inside the insulator 32.

  The thicknesses of the inner layer 32a and the outer layer 32b of the insulator 32 are 0.20 mm and 0.15 mm, respectively, and the outer diameter of the insulator 32 is 1.5 mm. Further, the end portion of the conductor wire 31 having a length of 5 mm is exposed from the insulator 32 at the end portion of the insulated wire 34 formed of the conductor wire 31 and the insulator 32 on the side covered with the molded resin molded body 33.

  Elastollan ET890 (manufactured by BASF Japan), which is an ether-based thermoplastic polyurethane, was used as the base polymer of the outer layer 32b of the insulator 32 and the material of the inner layer 32a. In addition, bentonite, polyacrylamide, or polyurethane was used as a water-swellable material added to the base polymer of the outer layer 32b.

  The mold resin molded body 33 has a cylindrical shape with a diameter of 6 mm and a length of 20 mm, and the insertion length of the insulated wire 34 into the mold resin molded body 33 is 10 mm or 15 mm. That is, the contact length L between the molded resin molded body 33 and the insulator 32 is 5 mm or 10 mm.

  The molded resin molded body 33 is Reny 1002F (manufactured by Mitsubishi Engineering Plastics), which is a polyamide containing 30% by mass of glass fibers, or Novaduran 5010G30X4 (Mitsubishi Engineering Plastics), which is a polybutylene terephthalate containing 30% by mass of glass fibers. Made of

  In this example, as shown in Table 1 described later, samples 30 having sample numbers 1 to 8 having different presence or types of water-swellable materials were prepared. Each of the samples 30 of sample numbers 1 to 8 further includes two types of samples 30 with different materials for the molded resin molded body 33. That is, there are 16 types of samples 30 prepared in the present embodiment. 50 samples 30 were prepared.

(Manufacture of evaluation samples)
Using a 40 mm single screw extruder (L / D = 24, L: screw length, D: screw diameter) for forming the inner layer 32a and a 24 mm single screw extruder (L / D = 20) for forming the outer layer 32b, An inner layer 32a having a thickness of 0.20 mm and an outer layer 32b having a thickness of 0.15 mm were simultaneously coated on the conductor wire 31 to form an insulator 32 having an outer diameter of 1.5 mm. The extrusion temperature was 200 ° C. for all.

  Next, the insulator 32 was peeled off at one end of the insulated wire 34 to expose the end portion of the conductor wire 31 having a length of 5 mm.

  Next, the mold resin molding 33 was formed by injection molding using a mold for insert molding so as to cover the end portion where the conductor wire 31 of the insulated wire 34 was exposed.

(Evaluation method)
<Evaluation of airtightness>
The airtightness test and the heat shock test were repeated alternately to evaluate how long the airtightness was maintained.

  FIG. 6B is a schematic diagram illustrating an implementation state of the airtightness test according to the present example. As shown in FIG. 6B, the end portion of the sample 30 on the mold resin molded body 33 side is immersed in the water 37 in the water tank 36, and the opposite end portion is connected to the air supply unit 35. .

  In the airtightness test, if air supplied from the air supply unit 35 through the conductor wire 31 to the mold resin molded body 33 side leaks out from the bonding surface of the mold resin molded body 33 and the insulator 32 as air bubbles 38, the airtightness test is performed. It was determined that the property was lost, and it was determined that the airtightness was maintained if no bubble 38 was generated. Here, in one airtightness test, 30 kPa of compressed air was supplied from the air supply unit 35 for 30 seconds.

  In the heat shock test, the sample 30 is left in water at 25 ° C. for 20 minutes, left in air at −40 ° C. for 20 minutes, and left in air at 120 ° C. for 20 minutes for one cycle. As a result, 10 cycles were carried out.

  That is, in this airtightness evaluation, every time the heat shock test was performed for 10 cycles, the airtightness test was performed to check whether the airtightness was maintained. The upper limit of the number of cycles of the heat shock test was set to 100.

<Destruction mode evaluation>
After conducting 100 cycles of the heat shock test, the insulated wire 34 is pulled out from the molded resin molded body 33, and the form of destruction is a cohesive failure in which the molded resin molded body 33 is broken, and the insulated wire 34 and the molded resin molded body 33 It was visually confirmed whether the interface fracture occurred at the interface.

<Conductor corrosion evaluation>
After conducting the fracture mode evaluation, the corrosion state of the conductor wire 31 covered with the molded resin molded body 33 was visually confirmed.

(Evaluation results)
Table 1 below shows the configurations of various samples 30 and the results of various evaluations.

  “Insulator outer layer material” in Table 1 indicates a material constituting the outer layer 32b, and “thermoplastic polyurethane” indicates the content of ether-based thermoplastic polyurethane (Elastolan ET890) as a base polymer, “bentonite”, “ “Polyacrylamide” and “polyurethane” indicate the content of each water-repellent material. The content of each material is shown in parts by mass with respect to 100 parts by mass of “thermoplastic polyurethane”. Further, the “electric wire insertion length” is the insertion length of the insulated wire 34 into the molded resin molded body 33.

  In addition, “polyamide” of “mold resin molding material” is an evaluation result when the mold resin molding 33 is made of polyamide (Reny 1002F) containing 30% by mass of glass fiber. “Polybutylene terephthalate” The evaluation result in case the molded object 33 consists of polybutylene terephthalate (Novaduran 5010G30X4) containing 30 mass% glass fiber is shown.

  Further, “after 10 cycles” of “airtightness evaluation” represents an evaluation result after 10 cycles of the heat shock test. “O” after “10 cycles” indicates that the airtightness of all 50 samples 30 was maintained, and means that the airtightness evaluation was passed. On the other hand, “x” after “10 cycles” indicates that the sample 30 whose airtightness has been lost is included, and means that the airtightness evaluation is unacceptable.

  The “limit cycle number” of “airtightness evaluation” is the number of cycles until the sample 30 in which the airtightness is lost appears among the 50 samples 30. Since the upper limit of the cycle number of the heat shock test is 100, 100 of the “limit cycle number” means that the airtightness is actually maintained for 100 cycles or more.

  “O” in “Conductor corrosion evaluation” indicates that no corrosion of the conductor wire 31 was confirmed in all 50 samples 30, and means that the conductor corrosion evaluation was passed. On the other hand, “x” in “conductor corrosion evaluation” indicates that the sample 30 in which the corrosion of the conductor wire 31 was confirmed to be included, and means that the conductor corrosion evaluation was rejected.

  As shown in Table 1, in the sample 30 of the sample numbers 1 to 6 in which the outer layer 32b includes a water-swellable material, the airtightness evaluation and the conductor corrosion are performed regardless of the material of the molded resin molded body 33. The evaluation passed.

  Sample 30 of Sample No. 1 was found to have not been strongly bonded to the molded resin molded body 33 and the insulator 32 because the interface fracture occurred in the fracture mode evaluation, but passed the conductor corrosion evaluation, and the mold resin The waterproofness inside the molded body 33 was maintained. This is because even if a gap is generated between the molded resin molded body 33 and the insulated wire 34, the outer layer 32b swells and closes the gap, thereby preventing water from entering the molded resin molded body 33. it is conceivable that.

  Since the sample 30 of the sample number 2 has a shorter “wire insertion length” than the sample 30 of the sample number 1 and the contact area between the molded resin molded body 33 and the insulated wire 34 is smaller, the “limit cycle number” is the sample number 1. Less than sample 30 and did not reach 100 cycles. However, the conductor corrosion evaluation conducted after 100 cycles of the heat shock test was passed, and the waterproof property inside the molded resin molded body 33 was maintained. It is considered that this is because the outer layer 32b absorbed water that had entered the slight gap that became the air path after the airtightness was broken.

  The “wire insertion length” of the sample 30 of the sample numbers 3 and 4 and the sample 30 of the sample numbers 5 and 6 are the same as the “wire insertion length” of the sample 30 of the sample numbers 1 and 2, respectively. In the shape evaluation, cohesive failure was observed, and the “limit cycle number” was 100 cycles. This is considered to be due to the increased adhesive force between the molded resin molded body 33 and the insulator 32 by using polyacrylamide or polyurethane as the water-swellable material added to the outer layer 32b.

  On the other hand, the sample 30 of the sample numbers 7 and 8 in which the outer layer 32b does not contain a water-swellable material failed in the conductor corrosion evaluation regardless of the material of the molded resin molded body 33.

  Since sample 30 of sample number 7 was cohesively broken in the fracture mode evaluation, it can be seen that the molded resin molded body 33 and the insulator 32 were strongly bonded, but after performing the heat shock test for 10 cycles. Although the airtightness evaluation conducted was successful, the “limit cycle number” was considerably small. This is presumably because the outer layer 32b does not contain a water-swellable material, so that water has entered a gap caused by a slight crack or peeling at the interface between the molded resin molded body 33 and the insulator 32. The water that has entered the gap is frozen to increase its volume and widen the gap, thereby forming an air path. Moreover, since the water that has entered the gap reaches the inside of the molded resin molded body 33, it is considered that the conductor corrosion test was also rejected.

  Sample 30 with sample number 8 has a shorter “wire insertion length” than sample 30 with sample number 5 and a smaller contact area between molded resin molded body 33 and insulated wire 34, so that “limit cycle number” is sample number 7. It was less than the sample 30, and the airtightness evaluation was not acceptable. Moreover, like the sample 30 of the sample number 7, it failed the conductor corrosion test.

  From these results, it can be seen that when the outer layer 32b contains a water-swellable material, high waterproofness inside the molded resin molded body 33 can be secured.

  And according to the result obtained by this example, the outer layer 15b has the insulator 15 containing the water-swellable material and the first mold resin molded body 13 that directly covers the terminal of the insulator 15. It is proved that the molded electric wire 10 according to the embodiment has excellent waterproof properties.

  Similarly, according to the result obtained by this embodiment, the second layer 26b has the sheath 26 in which the outer layer 26b includes a water-swellable material and the molded resin molded body 13 that directly covers the end of the sheath 26. It is supported that the molded electric wire 20 according to the embodiment has excellent waterproof properties.

  Although the embodiments and examples of the present invention have been described above, the present invention is not limited to the above-described embodiments and examples, and various modifications can be made without departing from the spirit of the invention.

  The embodiments and examples described above do not limit the invention according to the claims. It should be noted that not all combinations of features described in the embodiments and examples are necessarily essential to the means for solving the problems of the invention.

DESCRIPTION OF SYMBOLS 10, 20 ... Molded electric wire 12 ... Electronic circuit 13, 33 ... Molded resin molding 14, 31 ... Conductor wire 15, 25, 32 ... Insulator 15a, 26a, 32a ... Inner layer 15b, 26b, 32b ... Outer layer 16, 26 ... Sheath 18, 28, 34 ... Insulated wire

Claims (9)

A conductor wire;
An insulating member having a multilayer structure including a water-swellable material in an outermost layer covering the outer periphery of the conductor wire;
A molded resin molded body that directly covers the terminal of the insulating member;
A molded electric wire. The water-swellable material is a water-absorbing polymer or an inorganic filler;
The molded electric wire according to claim 1. The water-swellable material is poly (meth) acrylamide or polyurethane;
The molded electric wire according to claim 2. The molded resin molded body is made of polyamide or polybutylene terephthalate,
The molded electric wire according to any one of claims 1 to 3. The insulating member is an insulator that directly covers the outer periphery of the conductor wire.
The molded electric wire according to any one of claims 1 to 4. The insulating member is a sheath that indirectly covers the outer periphery of the conductor wire,
The molded electric wire according to any one of claims 1 to 4. Having a plurality of insulated wires made of the conductor wire and the insulator,
The ends of the plurality of insulated wires are collectively covered on the molded resin molded body,
The molded electric wire according to claim 5. A sheath that collectively covers the outer periphery of the plurality of insulated wires;
The mold resin molding does not contact the sheath;
The molded electric wire according to claim 7. After 100 cycles of a heat shock test in which 20-minute standing in water at 25 ° C., 20-minute standing in the atmosphere at −40 ° C., and 20-minute standing in the atmosphere at 120 ° C. are performed as one cycle. Even if it is immersed in water, the waterproof property inside the molded resin molded body is maintained.
The molded electric wire according to any one of claims 1 to 8.

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