JP2014192141A - Cable with terminal and wire harness - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cable with terminal and a wire harness which can keep excellent anticorrosion properties, in which when an anticorrosive for coating an electrical connection part of an electric wire conductor and a terminal metal fitting includes a hydrolyzable resin, a mechanical characteristic of the anticorrosive due to hydrolysis of the resin is not deteriorated even if it is used under high temperature environment.SOLUTION: An electrical connection part 6 in which a terminal metal fitting 5 and an electric wire conductor 3 of a cable 2 are electrically connected is coated with an anticorrosive 7 including the hydrolyzable resin and an additive agent having a carbodiimide group, thereby a cable 1 with terminal is formed.

Description

  The present invention relates to a coated electric wire with a terminal and a wire harness, and more particularly relates to a coated electric wire with a terminal excellent in corrosion resistance of an electric connection portion between an electric wire conductor and a terminal fitting, and a wire harness using the same.

  A terminal fitting is connected to the wire conductor at the end of the covered wire that is routed in a vehicle such as an automobile. It is required to prevent corrosion in the electrical connection portion where the terminal fitting and the wire conductor of the covered wire are electrically connected.

  In recent years, the use of aluminum or aluminum alloy as a material for electric wire conductors has been studied for the purpose of reducing the weight of vehicles such as automobiles. On the other hand, copper or a copper alloy is often used as a material for the terminal fitting. Further, the surface of the terminal fitting is often subjected to plating such as tin plating. In other words, the wire conductor and the terminal fitting may be made of different materials. If the wire conductor and the terminal fitting are made of different materials, corrosion due to contact with different metals occurs at the electrical connection portion. For this reason, it is calculated | required that an electrical connection part should carry out anticorrosion reliably. Then, in order to prevent the corrosion in the electrical connection part to which the terminal metal fitting and the electric wire conductor of the covered electric wire were electrically connected, for example, in Patent Document 1, the terminal metal fitting connected to the electric wire conductor is inserted and locked. A technique for injecting grease into a connector is disclosed.

Japanese Patent Application Laid-Open No. 5-159646

  When using grease to prevent corrosion at the electrical connection between the terminal fitting and the wire conductor, the handleability of the wire with terminal is reduced due to leakage of the grease injected into the connector. It is conceivable to use an anticorrosive agent made of a functional resin. Resins such as polyamide, polyester, and polyurethane are candidates for resins that can be used as such anticorrosives, but they have hydrolyzability. Therefore, when used in an in-vehicle environment that can reach up to around 120 ° C., hydrolysis may occur and mechanical properties of the anticorrosive agent may be deteriorated, and sufficient anticorrosion performance may not be exhibited.

  The problem to be solved by the present invention is that when the anticorrosive agent covering the electrical connection portion of the wire conductor and the terminal fitting contains a hydrolyzable resin, even if it is used in a high-temperature environment, An object of the present invention is to provide a coated electric wire with a terminal and a wire harness capable of maintaining high anticorrosion performance without being deteriorated in mechanical properties of the anticorrosive agent due to decomposition.

  In order to solve the above-described problems, a coated electric wire with a terminal according to the present invention is an addition of a hydrolyzable resin and a carbodiimide group to an electrical connection portion in which a terminal fitting and an electric wire conductor of the coated electric wire are electrically connected. The gist is that it is coated with an anticorrosive containing the agent.

  Here, it is preferable that the amount of the additive contained in the anticorrosive is in the range of 0.1 to 10% by mass.

  The resin is preferably at least one selected from a polyamide resin, a polyurethane resin, and a polyester resin, and is particularly preferably a polyamide resin.

  The wire harness concerning this invention makes it a summary to have said electric wire with a terminal.

  According to the coated electric wire with terminal according to the present invention, the additive having a carbodiimide group functions to suppress hydrolysis of the resin. Therefore, even when the electric wire with terminal is used in a high temperature environment, the resin is inhibited from being hydrolyzed by the influence of moisture in the air and the mechanical properties of the anticorrosive agent are lowered by the influence of the hydrolysis. It is prevented. Thereby, even when the covered electric wire with a terminal is used in a high temperature environment, the anticorrosion performance of the anticorrosive is maintained.

  Here, when the amount of the additive contained in the anticorrosive agent is in the range of 0.1 to 10% by mass, the hydrolysis of the resin is effectively suppressed by the effect of the additive, The viscosity of the anticorrosive increases due to the chemical reaction between the additive and the resin, and it is avoided that the application of the anticorrosive becomes difficult.

  Further, when the resin is at least one selected from polyamide resins, polyurethane resins, and polyester resins, particularly in the case of polyamide resins, high anticorrosion performance is imparted to the anticorrosive agent due to the properties of these resins. The And the hydrolysis of these resin is suppressed by the effect of an additive, The high anticorrosion performance is maintained even if it passes through use in a high temperature environment.

  Since the wire harness according to the present invention has the above-described electric wire with a terminal, even when used in a high temperature environment, the wire harness is not affected by hydrolysis of the resin constituting the anticorrosive, and between the terminal fitting and the electric wire conductor. High anticorrosion performance can be obtained at the electrical connection.

It is an external appearance perspective view of an example of the covered electric wire with a terminal of the present invention. FIG. 2 is a longitudinal sectional view taken along line AA in FIG. 1.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is an external perspective view showing an example of a coated electric wire with a terminal according to the present invention, and FIG. 2 is a longitudinal sectional view taken along line AA in FIG. As shown in FIG. 1 and FIG. 2, the coated electric wire with terminal 1 of the present invention is such that the electric wire conductor 3 of the covered electric wire 2 in which the electric wire conductor 3 is covered with the insulator 4 and the terminal fitting 5 are electrically connected by the electric connection portion 6. Connected to.

  The terminal fitting 5 includes a tab-like connection portion 51 made of an elongated flat plate connected to a counterpart terminal, a wire barrel 52 extending at the end of the connection portion 51, and an electric wire fixing portion made of an insulation barrel 53. 54.

  In the electrical connection portion 6, the insulator 4 at the end of the covered electric wire 2 is peeled off to expose the electric wire conductor 3, and the exposed electric wire conductor 3 is crimped to one side of the terminal metal fitting 5. And the terminal fitting 5 are connected. The wire barrel 52 of the terminal fitting 5 is crimped from above the wire conductor 3 of the covered electric wire 2 so that the wire conductor 3 and the terminal fitting 5 are electrically connected. Further, the insulation barrel 53 of the terminal fitting 5 is crimped from above the insulator 4 of the covered electric wire 2.

  And the electric connection part 6 is coat | covered with the anticorrosive 7 in the range shown with the dashed-dotted line in FIG. 1 is shown in a state where the anticorrosive 7 is seen through. The anticorrosive 7 prevents the metal portion from corroding due to the entry of moisture or the like into the wire conductor 3, the contact portion between the wire conductor 3 and the terminal fitting 5 from the outside.

  The specific part which the anticorrosive 7 has coat | covered is the following parts. As shown in FIG. 1, the tip 2 a side of the covered electric wire 2 is covered with the anticorrosive 7 so as to slightly protrude from the tip of the wire conductor 3 to the connecting portion 51 side of the terminal fitting 5. The tip 5 a side of the terminal fitting 5 is covered with the anticorrosive 7 so as to slightly protrude from the end of the insulation barrel 53 to the insulator 4 side of the covered electric wire 2. As shown in FIG. 2, the side surface 5 b of the terminal fitting 5 is also covered with the anticorrosive agent 7. The back surface 5 c of the terminal fitting 5 is not covered with the anticorrosive 7. In this way, the electrical connection portion 6 is covered with the anticorrosive agent 7 with a predetermined thickness along the outer peripheral shape of the terminal fitting 5 and the covered electric wire 2. The portion where the end of the covered wire 2 is peeled off and the wire conductor 3 is exposed is completely covered with the anticorrosive 7 and is not exposed to the outside. If the electrical connection is not affected, the back side of the wire fixing portion 54 of the terminal fitting 5 (including the back side of the wire barrel 52 and the insulation barrel 53) may be covered with the anticorrosive 7. .

  Accordingly, three of the peripheral ends of the anticorrosive agent 7 that covers the electrical connection portion 6 are in contact with the surface of the terminal fitting 5, and one is in contact with the surface of the insulator 4. That is, most of the peripheral edge of the anticorrosive 7 is in contact with the surface of the terminal fitting 5.

  The anticorrosive 7 has the following specific composition. The anticorrosive 7 comprises a hydrolyzable resin and an additive having a carbodiimide group (—N═C═N—).

  Examples of the hydrolyzable resin include polyamide resin, polyurethane resin, and polyester resin. These may be used alone or in combination of two or more. Moreover, you may mix with resin which does not have hydrolyzability. Of these resins, the curable resin is finally cured.

  Of the above resins, it is most preferable to use a polyamide resin. This is because polyamide resin is excellent in adhesion to metal. Specific examples of the polyamide resin include nylon 6, nylon 66, and the like.

  Examples of the additive having a carbodiimide group contained in the anticorrosive 7 include dicyclohexylcarbodiimide, diisopropylcarbodiimide, 1-ethyl-3- (3-dimethylaminopropyl) carbodiimide hydrochloride, 3- (dimethylamino) propylethylcarbodiimide, tert- Examples thereof include butyl ethyl carbodiimide and di-tert-butyl carbodiimide.

  Furthermore, additives such as coloring pigments, viscosity modifiers, anti-aging agents, inorganic fillers, storage stabilizers, and dispersants may be added to the anticorrosive agent 7.

  The additive having a carbodiimide group plays a role in preventing the hydrolyzable resin from being hydrolyzed in the anticorrosive agent 7. If the anticorrosive agent 7 does not contain an additive having a carbodiimide group, when the coated electric wire with terminal is used in a high temperature environment such as an in-vehicle environment as long as 120 ° C., including moisture in the atmosphere and anticorrosive agent The hydrolyzable resin constituting the anticorrosive 7 is subject to hydrolysis due to the influence of moisture taken into the constituent member of the covered electric wire with terminal. Then, the mechanical properties of the anticorrosive agent 7 are deteriorated, and a gap is generated between the anticorrosive agent 7 and the terminal fitting 5 or the electric wire conductor 3, or cracks are generated in the anticorrosive agent 7. Will invade. However, in the electric wire with terminal according to the present invention, since the anticorrosive 7 contains an additive having a carbodiimide group, hydrolysis of the hydrolyzable resin is suppressed, and such anticorrosion brought about by hydrolysis of the resin. The deterioration of the anticorrosion performance of the agent 7 is prevented.

  The content of the additive having a carbodiimide group in the anticorrosive 7 is preferably in the range of 0.1 to 10% by mass. When the content is 0.1% by mass or more, a high effect is exhibited in suppressing hydrolysis, and the anticorrosion performance of the anticorrosive 7 under a high temperature environment is effectively maintained. On the other hand, if the content of the additive having a carbodiimide group is too large, a chemical bond is formed between the additive having a carbodiimide group and the hydrolyzable resin in the preparation stage of the anticorrosive 7, and the viscosity of the anticorrosive is low. It will increase. Then, the process of apply | coating the anticorrosive 7 to the electrical connection part 6 becomes difficult. If content of the additive which has a carbodiimide group shall be 10 mass% or less, the anticorrosive agent 7 can be apply | coated easily and the productivity of the covered electric wire 1 with a terminal will become high.

  The anticorrosive agent 7 can be adjusted by mixing a hydrolyzable resin, an additive having a carbodiimide group, and other necessary additives. At this time, temperature adjustment or the like may be appropriately performed in order to facilitate mixing.

  Application | coating of the anticorrosive 7 can use well-known means, such as a dripping method, the apply | coating method, and the extrusion method. Further, when the anticorrosive agent 7 is applied, the temperature of the anticorrosive agent 7 may be adjusted by heating, cooling, or the like. Moreover, in order to improve the permeability (coating property) of the anticorrosive agent 7, when applying, the anticorrosive agent 7 may be diluted with a solvent to form a liquid. In the case where the resin in the anticorrosive 7 is curable, an appropriate curing treatment such as ultraviolet irradiation, heating, or humidification may be performed after application.

  Hereinafter, each part of the covered electric wire 1 with a terminal is demonstrated.

  The electric wire conductor 3 of the covered electric wire 2 is made of a stranded wire formed by twisting a plurality of strands 3a. In this case, the stranded wire may be composed of one type of metal strand or may be composed of two or more types of metal strand. Moreover, the twisted wire may contain the strand etc. which consist of organic fibers other than a metal strand. Note that “consisting of one type of metal strand” means that all the metal strands constituting the stranded wire are made of the same metal material, and “consisting of two or more types of metal strands” This means that the wire contains metal wires made of different metal materials. The stranded wire may include a reinforcing wire (tension member) for reinforcing the covered electric wire.

  Examples of the material of the metal wire constituting the wire conductor 3 include copper, a copper alloy, aluminum, an aluminum alloy, or a material obtained by applying various platings to these materials. Examples of the material of the metal strand as the reinforcing wire include copper alloy, titanium, tungsten, and stainless steel. Examples of the organic fiber as the reinforcing wire include Kevlar.

  Examples of the material of the insulator 4 include rubber, polyolefin, PVC, and thermoplastic elastomer. These may be used alone or in combination of two or more. Various additives may be appropriately added to the material of the insulator 4. Examples of the additive include a flame retardant, a filler, a colorant and the like.

  Examples of the material (material for the base material) of the terminal fitting 5 include various copper alloys and copper in addition to brass that is generally used. A part (for example, a contact) or the entire surface of the terminal fitting 5 may be plated with various metals such as tin, nickel, and gold.

  The wire harness concerning this invention consists of a some covered electric wire containing the covered electric wire 1 with a terminal concerning the said invention. All of the covered electric wires constituting the wire harness may be the terminal-attached electric wire 1 according to the present invention, or only a part thereof may be the terminal-attached electric wire 1 according to the present invention.

  Examples of the present invention and comparative examples are shown below. In addition, this invention is not limited by these Examples.

<Preparation of anticorrosive>
(Examples 1-4)
In a state where Macromelt 6202 (manufactured by Henkel) was heated to 180 ° C. and melted as a polyamide resin, carbodilite (Nisshinbo Chemical Co., Ltd.), which is an additive having a carbodiimide group, was added and kneaded. The anticorrosive agent concerning 4 was prepared. The content of the additive in each anticorrosive is shown in Table 1 below.

(Comparative Example 1)
An anticorrosive agent according to Comparative Example 1 was prepared in the same manner as the anticorrosive agent according to Examples 1 to 4 except that the additive having a carbodiimide group was not mixed in the anticorrosive agent.

<Thermal degradation test>
In order to evaluate the decrease in the mechanical strength of the corrosion inhibitor due to hydrolysis, a thermal deterioration test was conducted. The anticorrosive agent concerning each Example and a comparative example was shape | molded in the sheet form, and the dumbbell piece (JIS K6251 6 dumbbell) was created. A thermal deterioration test was performed in which the dumbbell pieces were left at 120 ° C. for 120 hours. Before and after the thermal degradation test, the dumbbell pieces were measured for elongation at break according to JIS K6251. The case where the rate of decrease in elongation after the thermal deterioration test with respect to the initial state is less than 200% is accepted (mechanical strength is sufficient) “◯”, and the case where it is 200% or more is rejected (mechanical strength is insufficient) There was “x”.

<Salt spray test (room temperature)>
In order to evaluate the anticorrosion performance of the anticorrosive, a salt spray test was conducted. First, the sample was prepared using the anticorrosive agent concerning each Example and a comparative example. In other words, a polypropylene resin was extruded and coated around a wire conductor (conductor cross-sectional area of 0.75 mm ² ) twisted with aluminum alloy strands, thereby creating a covered wire. Next, after stripping the end of the covered electric wire to expose the electric wire conductor, a female crimp terminal (made of brass base material tin-plated) widely used for automobiles is used as the end of the covered electric wire. It crimped and crimped. As shown in FIGS. 1 and 2, the anticorrosive material according to each of the examples and the comparative examples was applied to the electrical connection portion between the wire conductor and the crimp terminal with a thickness of 0.05 mm.

  About each sample, the salt spray test was done with respect to the electrical connection part based on JISC0023. In other words, for a sample that has undergone a 96-hour salt spray test, the appearance of the electrical connection portion is visually determined after the resin coating has been peeled off, and if no corrosion occurs (if no rust has occurred), the test passes. ○ ”, when corrosion occurs (when rust occurs), it is determined as“ failed ”.

<Salt spray test (after heat deterioration)>
In order to evaluate the degree of decrease in the anticorrosive performance of the anticorrosive due to thermal deterioration, a salt spray test was performed on the anticorrosive after thermal deterioration in the same manner as described above. After that, the appearance is observed and the presence or absence of corrosion of the aluminum is confirmed. If there is no corrosion (when rust is not generated), the test is “Yes”, and if corrosion is generated (rust is generated). Case) was rejected as “x”.

<Results and discussion>
Table 1 shows the content (unit: mass%) of additives having a carbodiimide group in the anticorrosives according to each example and comparative example, thermal deterioration test, salt spray test (room temperature), salt spray test (after heat deterioration) ) Result.

  According to Table 1, about the anticorrosive agent concerning the comparative example 1 which does not contain the additive which has a carbodiimide group, the result of a thermal deterioration test is disqualified. This is thought to be because the hydrolyzable resin is hydrolyzed in a high-temperature environment due to moisture in the air and moisture taken into the anticorrosive agent, and the mechanical strength of the anticorrosive agent is reduced. It is done. On the other hand, about the anticorrosive agent concerning each Example containing the additive which has a carbodiimide group, the result of the thermal deterioration test has passed. This indicates that by adding an additive having a carbodiimide group to the anticorrosive agent, the hydrolysis of the resin is suppressed, and even when the anticorrosive agent is exposed to a high temperature environment, high mechanical strength is maintained. Yes.

  Looking at the results of the salt spray test after thermal degradation, the anticorrosive agent according to Comparative Example 1 that does not contain an additive having a carbodiimide group is rejected, but contains an additive having a carbodiimide group. In the anticorrosive agent concerning each Example to do, it is a pass. This corresponds to the result of the thermal degradation test described above, and by adding a carbodiimide group to the anticorrosive agent, the hydrolysis of the resin is suppressed, and the mechanical strength is maintained even through a high temperature environment. , Indicating that the anticorrosive maintains high anticorrosion performance.

  The salt spray test at room temperature shows the anticorrosive performance of the anticorrosive under conditions not affected by hydrolysis. According to the results in Table 1, an additive having a carbodiimide group is included in the anticorrosive. However, the anticorrosion performance of the anticorrosive agent has not deteriorated.

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

DESCRIPTION OF SYMBOLS 1 Coated electric wire with terminal 2 Coated electric wire 3 Electric wire conductor 4 Insulator 5 Terminal metal fitting 52 Wire barrel 53 Insulation barrel 54 Electric wire fixing part 6 Electrical connection part 7 Anticorrosive

Claims (5)

  The electrical connection portion where the terminal metal fitting and the wire conductor of the covered electric wire are electrically connected is covered with an anticorrosive containing a hydrolyzable resin and an additive having a carbodiimide group. Covered wire with terminal.   The amount of the said additive contained in the said anticorrosive exists in the range of 0.1-10 mass%, The covered electric wire with a terminal of Claim 1 characterized by the above-mentioned.   3. The covered electric wire with terminal according to claim 1, wherein the resin is at least one selected from a polyamide resin, a polyurethane resin, and a polyester resin.   The said resin is a polyamide resin, The covered electric wire with a terminal of Claim 3 characterized by the above-mentioned.   A wire harness comprising the covered electric wire with a terminal according to any one of claims 1 to 4.

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