JP2014110151A - Terminal-fitted cable, wire harness and anticorrosive agent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cable and a wire harness in which the electric connection part of an electric wire conductor and a terminal metal fitting is covered with an anticorrosive agent having high anticorrosion performance, heat resistance, and resistance to a cold heat cycle, and the anticorrosive agent capable of exhibiting such high anticorrosion performance and heat resistance.SOLUTION: The terminal-fitted cable 1 is composed by covering an electric connection part 6 in which a terminal metal fitting 5 and the electric wire conductor 3 of a cable 2 are electrically connected with an anticorrosive agent 7 comprising a curable silicone resin in which rotational viscosity at 25°C in an un-cured state measured in accordance with JIS K6249 lies in the range of 1,000 mPa s to less than 40,000 mP s, and elongation upon cutting measured in accordance with JIS K6249 about the conditions after curing is 150% or higher.

Description

  The present invention relates to a coated electric wire with a terminal, a wire harness, and an anticorrosive, and more specifically, is used for a coated electric wire with a terminal excellent in anticorrosive property of an electric connection portion between a wire conductor and a terminal fitting, a wire harness, and anticorrosion thereof. It relates to anticorrosives.

  2. Description of the Related Art Conventionally, as an electric wire routed in a vehicle such as an automobile, a covered electric wire in which an outer periphery of a conductor made of a soft material such as tough pitch copper is coated with an insulator is widely used. In the terminal of this kind of covered electric wire, a terminal fitting is connected to a conductor exposed by peeling off an insulator. The terminal fitting electrically connected to the end of the covered electric wire is inserted and locked to the connector. A plurality of such covered electric wires with terminals are bundled to form a wire harness. In vehicles such as automobiles, wiring is usually performed in the form of a wire harness.

  When the wire harness is routed in an engine room in a flooded area or in some indoor environments, rust is generated at the electrical connection where the wire conductor and terminal fitting come into contact under the influence of heat and water. It becomes easy. Therefore, when wiring a wire harness in such an environment, it is necessary to prevent corrosion in the electrical connection portion.

  In order to prevent corrosion at the electrical connection portion, for example, Patent Document 1 discloses a technique for injecting grease into a connector in which a terminal fitting connected to a wire conductor is inserted and locked.

Japanese Patent Laid-Open No. 05-159846

  In recent years, the movement to improve fuel efficiency has been accelerated by reducing the weight of vehicles such as automobiles, and there is a demand for reducing the weight of the wire material constituting the wire harness. Therefore, the use of aluminum for the wire conductor has been studied.

  However, copper or a copper alloy having excellent electrical characteristics is generally used for the terminal fitting. Therefore, the combination of an aluminum electric wire and a copper terminal fitting is often applied. If the material of the wire conductor and the terminal fitting are different, corrosion due to contact with different metals occurs at the electrical connection portion. This type of corrosion is more likely to occur than when the wire conductor and the terminal fitting are the same material. Therefore, an anticorrosive agent that can reliably prevent the electrical connection portion is required.

  However, the grease that has been used conventionally cannot sufficiently prevent water from entering unless it is poured into the connector closely. If an attempt is made to increase the filling amount of grease in order to enhance the anticorrosion effect, the grease will be applied even to a portion where the anticorrosion is not originally required. Furthermore, excessive filling causes stickiness of the connector and the electric wire, and deteriorates handleability. Therefore, an anticorrosive capable of exhibiting high anticorrosion performance is required as a substitute for such problematic grease.

  Moreover, in view of the fact that wire harnesses are often used in environments exposed to high temperatures, such as engine rooms, as described above, anticorrosives used for anticorrosion of electrical connections have high heat resistance. It is necessary to maintain a high anticorrosion performance even when exposed to a cold cycle.

  The problem to be solved by the present invention is that the electrical connection portion of the wire conductor and the terminal fitting has high anticorrosion performance and heat resistance, and is coated with an anticorrosive agent that can maintain high anticorrosion performance even when exposed to a cold cycle. An object of the present invention is to provide an electric wire and a wire harness, and to provide an anticorrosive capable of exhibiting such high anticorrosion performance, heat resistance, and resistance to a thermal cycle.

  In order to solve the above-mentioned problems, the coated electric wire with a terminal according to the present invention is an uncured state in which an electrical connection portion in which a terminal fitting and an electric wire conductor of the coated electric wire are electrically connected is measured according to JIS K6249. Containing a curable silicone resin having a rotational viscosity at 25 ° C. of 1000 mPa · s or more and less than 40000 mPa · s, and a state after curing of 150% or more when measured in accordance with JIS K6249. The gist is that it is coated with a cured product of an anticorrosive.

  Here, the curable silicone resin is preferably a room temperature moisture curable resin.

  Further, it is preferable that the electric wire conductor has a strand made of aluminum or an aluminum alloy, and the terminal fitting is made of copper or a copper alloy.

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

  The anticorrosive agent according to the present invention has a rotational viscosity at 25 ° C. in an uncured state measured in accordance with JIS K6249 of 1000 mPa · s or more and less than 40000 mPa · s, and the state after curing conforms to JIS K6249. The gist is to contain a curable silicone resin having an elongation at break of 150% or more as measured.

  Here, the curable silicone resin is preferably a room temperature moisture curable resin.

  According to the coated electric wire with a terminal according to the present invention, since the anticorrosive agent contains a silicone resin having a high heat resistance, the anticorrosive structure covering the electrical connection portion of the coated electric wire with a terminal has a high heat resistance. In addition, since the silicone resin has the predetermined rotational viscosity in an uncured state, it has excellent coating properties and has the predetermined elongation at break after curing, so that high corrosion resistance can be imparted to the electrical connection portion. it can. Furthermore, even if the anticorrosive is exposed to a cold cycle, the occurrence of mechanical damage such as cracks is prevented, and high anticorrosion performance is maintained.

  Here, when the curable silicone resin is a room temperature moisture curable type, no special treatment is required for curing the anticorrosive agent, and the handling property of the anticorrosive agent is enhanced, so that the productivity of the covered electric wire with terminal is increased. .

  Further, when the electric wire conductor has a strand made of aluminum or an aluminum alloy and the terminal fitting is made of copper or a copper alloy, a dissimilar metal is in contact with the electric connection portion of the covered electric wire with a terminal. If the treatment is not performed, the probability of corrosion increases, but by using a coated electric wire with a terminal using an anticorrosive agent having excellent anticorrosion performance as described above, the corrosion resistance of the electrical connection portion is improved, Connection reliability is excellent.

  The wire harness according to the present invention has a terminal-attached electric wire whose electrical connection portion is coated with an anticorrosive having high anticorrosion performance, heat resistance, and heat cycle resistance as described above. It can be suitably arranged.

  Since the anticorrosive agent according to the present invention contains a curable silicone resin having a specific rotational viscosity and elongation at break, the anticorrosive agent has high anticorrosion performance, heat resistance, and resistance to a thermal cycle.

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. It is a figure for demonstrating the method of a corrosion test.

  Hereinafter, a covered covered electric wire according to an embodiment of the present invention (hereinafter sometimes referred to as “the present covered electric wire”) and a wire harness according to an embodiment of the present invention (hereinafter referred to as “the present wire harness”) using the drawings. And the anticorrosive according to the present invention (hereinafter sometimes referred to as “the anticorrosive”) will be described in detail.

1. This anticorrosive agent This anticorrosive agent has a curable silicone resin as a main component. The anticorrosive agent is applied to a portion to be anticorrosive in an uncured state and then subjected to a curing treatment. Since the silicone resin generally has high heat resistance, the anticorrosive agent has high heat resistance and can be suitably used even in a high temperature environment.

  The curable silicone resin has a rotational viscosity at 25 ° C. measured in accordance with JIS K6249 with respect to an uncured state of 1000 mPa · s or more and less than 40000 mPa · s.

  When the viscosity is less than 1000 mPa · s, it flows out from the portion where the curable silicone resin is applied at the time of application, and it becomes difficult to apply a sufficient amount to a portion where corrosion resistance is required. Therefore, it becomes difficult to obtain high anticorrosion performance. Furthermore, from the viewpoint of the efficiency of the anticorrosion treatment and the anticorrosion performance, the viscosity is preferably 2000 mPa · s or more.

  On the other hand, when the viscosity is 40000 mPa · s or more, the anticorrosive agent does not exhibit sufficient fluidity at the time of application, and it becomes difficult to uniformly apply the sufficient anticorrosive agent to the site where the anticorrosion property is required. Therefore, it becomes difficult to obtain high anticorrosion performance. Furthermore, from the viewpoint of the efficiency of the anticorrosion treatment and the anticorrosion performance, the viscosity is preferably less than 35000 mPa · s.

  Further, the curable silicone resin has an elongation at break of 150% or more measured according to JIS K6249 with respect to the cured state.

  When the elongation is less than 150%, the anticorrosive agent may be mechanically damaged such as cracking when exposed to a cold cycle (cooling and heating cycle), and it is difficult to obtain anticorrosion performance. The elongation is preferably 200% or more. There is no particular upper limit for the elongation.

  The curable silicone resin used in the anticorrosive is preferably a room temperature moisture curable silicone resin. This is because, after application in an uncured state, it is cured with moisture in the atmosphere at room temperature without performing a special curing treatment, and therefore, it is excellent in handling properties and can perform the anticorrosion treatment with high efficiency.

  Examples of the curable silicone resin include monofunctional silicone resins, bifunctional silicone resins, trifunctional silicone resins, and polyfunctional silicone resins.

  The present anticorrosive may be composed of a single curable silicone resin, or two or more curable silicone resins may be mixed and combined. Furthermore, if necessary, additives, other monomers, oligomers, polymers, and the like may be mixed as long as the physical properties are not impaired.

  The additive is not particularly limited as long as it is an additive generally used for resin molding materials. Specifically, for example, a curing agent, a curing catalyst, an inorganic filler, an antioxidant, a metal deactivator (copper damage inhibitor), an ultraviolet absorber, an ultraviolet masking agent, a flame retardant aid, a processing aid ( Lubricants, waxes, etc.), carbon and other coloring pigments, flexibility imparting materials, impact resistance imparting materials, organic fillers, diluents (solvents, etc.), thixotropic materials, various coupling materials, defoaming materials, A leveling material etc. can be mentioned.

  This anticorrosive agent can be used suitably for corrosion prevention of the electrical connection part of the conductor of a covered electric wire routed to vehicles, such as a car, and a terminal metal fitting, for example.

2. Next, the present covered electric wire will be described.

  As shown in FIG. 1 and FIG. 2, this covered electric wire 1 includes a covered electric wire 2 in which an outer periphery of an electric wire conductor 3 is covered with an insulator 4 and a terminal fitting connected to the end of the electric wire conductor 3 of the covered electric wire 2. And 5.

In the covered electric wire 2, the insulator 4 is peeled off at the end to expose the electric wire conductor 3, and the terminal fitting 5 is connected to the exposed end of the electric wire conductor 3. The electric wire conductor 3 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) that reinforces the covered electric wire.

  Examples of the metal wire material include copper, copper alloy, aluminum, aluminum alloy, and materials 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.

  The terminal metal fitting 5 includes a tab-shaped connection portion 51 connected to the counterpart terminal, a wire barrel 52 that extends from the proximal end of the connection portion 51 and crimps the end of the wire conductor 3 of the covered wire 2, a wire An insulation barrel 53 that extends from the barrel 52 and crimps the insulator 4 at the end of the covered electric wire 2 is provided.

  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.

  In the electrical connection portion between the wire conductor 3 and the terminal fitting 5 at the wire terminal, a part of the wire conductor 3 is exposed. The exposed portion of the coated electric wire 1 is covered with the anticorrosive agent. Specifically, the anticorrosive coating film 7 covers the boundary between the proximal end of the connection portion 51 of the terminal metal fitting 5 and the distal end of the wire conductor 3 up to the proximal end of the connection portion 51, and the insulation of the terminal metal fitting 5. The insulator 4 is covered up to the insulator 4 across the boundary between the insulation barrel 53 and the insulator 4.

  The anticorrosive to be used can be selected from the above physical property range in consideration of the combination of the material of the wire conductor 3 and the material of the terminal fitting 5. The thickness of the anticorrosive coating film 7 may be adjusted as appropriate, but is preferably within a range of 0.01 mm to 0.1 mm. If the thickness of the coating film 7 is too thick, it is difficult to insert the terminal fitting 5 into the connector. Moreover, when the thickness of the coating film 7 is too thin, an anticorrosion effect will fall easily.

  The anticorrosive is formed by crimping the terminal fitting 5 at the end of the electric wire to connect the wire conductor 3 and the terminal fitting 5, and then the surface of the connecting portion between the electric wire conductor 3 and the terminal fitting 5, that is, the surface of the insulator 4 at the end. And the surface of the insulation barrel 53, the surface of the wire barrel 52, the exposed surface of the wire conductor 3, and the base end surface of the connecting portion 51. Thereby, the coating film 7 is formed on the surface of the connection portion between the wire conductor 3 and the terminal fitting 5.

  If the electrical connection is not affected, the coating film 7 is also applied to the back side of the tab-like connection part 51 protruding from the wire barrel 52 of the terminal fitting 5, and the back side of the wire barrel 52 and the insulation barrel 53. It may be formed.

  In applying the anticorrosive, a method such as dropping or applying can be used. Heating and cooling may be performed as necessary.

  The coating film 7 of the anticorrosive is cured after application to the electrical connection portion. By curing, the mechanical strength of the coating film 7 is improved. When the curable silicone resin contained in the anticorrosive agent is a moisture curable resin, the curing proceeds after the coating film 7 is applied in the air without performing a special curing treatment.

  Since the anticorrosive is solidified after application, the anticorrosive can be fixed in a place where it has been applied over a long period of time, as well as having no risk of stickiness during handling. Therefore, the anticorrosion effect can be maintained over a long period, and the anticorrosion effect can be maintained over a long period.

3. The present wire harness is formed by bundling a plurality of covered electric wires with terminals including the main covered electric wire 1. In the present wire harness, a part of the covered electric wire included in the harness may be the main covered electric wire 1, or all may be the main covered electric wire 1.

  In the wire harness, the plurality of covered electric wires may be bundled by tape winding, or may be covered by an external part such as a round tube, a corrugated tube, or a protector.

  This wire harness is suitable for being routed in a vehicle such as an automobile, and is particularly suitable for being routed in an engine room or a vehicle in a wet area. In such a place, since it is easy to receive the influence of heat and water, if the wire harness is routed in such a place, rust is likely to occur in the electrical connection portion between the electric wire conductor and the terminal fitting. According to this wire harness, generation | occurrence | production of the rust in the electrical connection part of the electric wire conductor 3 and the terminal metal fitting 5 in this covered electric wire 1 can be suppressed effectively.

  Hereinafter, the present invention will be described in detail with reference to examples. In addition, this invention is not limited by these Examples.

1. Preparation of covered electric wire For 100 parts by mass of polyvinyl chloride (degree of polymerization 1300), 40 parts by mass of diisononyl phthalate as a plasticizer, 20 parts by mass of calcium bicarbonate as a filler, 5 parts by mass of calcium zinc-based stabilizer as a stabilizer A polyvinyl chloride composition was prepared by mixing at 180 ° C. with an open roll and molding into pellets with a pelletizer.

  Next, using a 50 mm extruder, the polyvinyl chloride composition obtained above was 0.28 mm thick around a conductor (cross-sectional area 0.75 mm) made of an aluminum alloy twisted wire in which seven aluminum alloy wires were twisted together. And extrusion coated. This produced the covered electric wire (PVC electric wire).

2. Production of coated electric wire with terminal After stripping the end of the produced coated electric wire and exposing the electric wire conductor, it covers a male crimp terminal fitting (tab width 0.64 mm) made of brass, which is widely used for automobiles. It crimped and crimped to the end of the electric wire.

  Next, the following various moisture-curing silicone resins were applied as an anticorrosive agent to the electrical connection portion between the electric wire conductor and the terminal fitting, and the exposed wire conductor and the barrel of the terminal fitting were covered with the anticorrosive agent. Then, the electric wire with a terminal was produced by leaving it in air | atmosphere at room temperature and carrying out the moisture hardening of the anticorrosive. Here, the anticorrosive was applied at a thickness of 0.05 mm. In addition, about the anticorrosive agent concerning the comparative example 3, due to low viscosity, the uniform application | coating with this thickness was not able to be performed.

3. Evaluation Method Using a coated electric wire with a terminal coated with various anticorrosives, a thermal cycle test and an evaluation of anticorrosion performance were performed as follows.

(Cooling cycle test)
The cooling cycle which hold | maintained each electric wire with a terminal produced above at -40 degreeC and 120 degreeC alternately for 30 minutes each was repeated 500 times. Thereafter, the appearance of the anticorrosive coating film was visually confirmed. Those in which no cracks were observed were evaluated as “good”, and those in which cracks were observed were determined as “failed”.

(Anti-corrosion performance)
As shown in FIG. 3, the prepared covered electric wires 1 with terminals are connected to the + pole of the 12V power supply 10, and the pure copper plate 20 (width 10 mm × length 20 mm × thickness 1 mm) is connected to the −pole of the 12V power supply 10. Then, the electrical connection portion between the wire conductor of the coated electric wire with terminal 1 and the terminal fitting and the pure copper plate 20 were immersed in 300 cc of NaCl 5% aqueous solution 30 and energized at 12 V for 2 minutes. After energization, ICP emission analysis of NaCl 5% aqueous solution 30 was performed, and the elution amount of aluminum ions from the wire conductor of the covered coated wire 1 was measured. The case where the elution amount was less than 0.1 ppm was regarded as acceptable “◯”, and the case where the elution amount was 0.1 ppm or more was regarded as unacceptable “x”.

  Table 1 summarizes the (rotational) viscosity at 25 ° C. when uncured, the (cut) elongation after curing, and the evaluation results measured in accordance with JIS K6249 of the anticorrosives according to Examples and Comparative Examples.

(Silicone resin)
Example 1: “TSE3975W” manufactured by Momentive Performance Materials
Example 2: “KE3495” manufactured by Shin-Etsu Silicone
Example 3: “SE9187L” manufactured by Toray Dow Corning
Comparative Example 1: “TSE3395W” manufactured by Momentive Performance Materials
Comparative Example 2: Momentive Performance Materials “TN3305”
Comparative Example 3: “KE3420” manufactured by Shin-Etsu Silicone
Comparative Example 4: 90% by mass of “SE9187L” manufactured by Toray Dow Corning Co., Ltd. and 10% by mass of silicone oil “KF-965-100CS” manufactured by Shin-Etsu Silicone Co., Ltd. were weighed at room temperature, and a metal bowl was used in a beaker. The silicone resin according to Comparative Example 4 was obtained by manually stirring for 10 minutes.

  According to Table 1, the following can be understood. That is, the anticorrosive agent according to each comparative example has a viscosity at 25 ° C. when uncured and / or elongation at break after curing outside the scope of the present invention, and is inferior in anticorrosion performance and resistance to a thermal cycle. Specifically, in Comparative Example 1 and Comparative Example 3, since the elongation after curing is too small, it is considered that cracks are generated in the cold cycle. Moreover, in Comparative Examples 2-4, it is thought that sufficient anti-corrosion performance is not achieved by the viscosity at the time of uncured being outside the definition of the present invention and / or the elongation after curing is too small. .

  On the other hand, the anticorrosive agent according to each example has a viscosity at 25 ° C. when uncured and an elongation at break after curing within the range defined by the present invention, and exhibits high anticorrosion performance. . This is because the viscosity is in a specific range, so that the anticorrosive is sufficiently penetrated into the electrical connection between the coated wire and the terminal fitting, and is applied with a uniform thickness. By having it, it is thought that it is a result which the anticorrosive adhered sufficiently with respect to the electrical connection part.

  Furthermore, in each Example, a crack is not generated by a thermal cycle. Thereby, it is thought that high anticorrosion performance is maintained even if it passes through a cooling-heat cycle. Since the elongation is in a specific range, it is considered that mechanical damage did not occur in the anticorrosive agent even when the anticorrosive agent repeatedly expanded and contracted by the cold cycle.

  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.

  For example, in the covered electric wire with a terminal 1 represented in the above embodiment, a male terminal having a tab-like connecting portion 51 is shown as the terminal fitting 5, but is not limited thereto, For example, it may be a female terminal that can be fitted with a male terminal, or a tuning fork terminal. Further, the terminal fitting 5 may not be provided with the insulation barrel 53 but may be crimped only by the wire barrel 52. Furthermore, the method for connecting the wire conductor 3 and the terminal fitting 5 is not limited to the crimping by the barrel, and may be a method such as pressure resistance welding, ultrasonic welding, or soldering. Moreover, in the said embodiment, although the conductor 3 which consists of a twisted wire is shown, the conductor 3 may be a single core wire.

1 Coated electric wire with terminal 2 Coated electric wire 3 Electric wire conductor 4 Insulator 5 Terminal fitting 7 Anticorrosive (coating)

Claims (6)

  An electrical connection portion in which the terminal fitting and the wire conductor of the covered electric wire are electrically connected has a rotational viscosity at 25 ° C. in an uncured state measured in accordance with JIS K6249 of 1000 mPa · s or more and 40000 mPa · s. A terminal characterized by being coated with a cured product of an anticorrosive agent containing a curable silicone resin having an elongation at break of 150% or more as measured in accordance with JIS K6249 with respect to the state after curing. Covered electric wire.   The said curable silicone resin is a room temperature moisture hardening type, The covered electric wire with a terminal of Claim 1 characterized by the above-mentioned.   The electric wire with a terminal according to claim 1 or 2, wherein the electric wire conductor has a strand made of aluminum or an aluminum alloy, and the terminal fitting is made of copper or a copper alloy.   It has an electric wire with a terminal given in any 1 paragraph of Claims 1-3, A wire harness characterized by things.   The rotational viscosity at 25 ° C. in an uncured state measured in accordance with JIS K6249 is 1000 mPa · s or more and less than 40000 mPa · s, and the elongation after cutting measured in accordance with JIS K6249 with respect to the state after curing. An anticorrosive agent comprising a curable silicone resin having a content of 150% or more.   6. The anticorrosive agent according to claim 5, wherein the curable silicone resin is a room temperature moisture curable type.

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