JP6002406B2 - Electrical wire end sealing method - Google Patents

Description

  The present invention relates to a sealing process for an electric wire terminal part, and more particularly, to an electric wire terminal part sealing process method for an electric wire provided with a connection terminal in a terminal part.

  As an electric wire provided with a connection terminal at a terminal portion, there is a ground electric wire or the like that is generally applied to a wire harness for a vehicle. The ground wire is used by being connected to an appropriate ground portion (for example, a vehicle body) in a state where a ground connection terminal fixed to the terminal is exposed to the outside. Therefore, moisture may enter from the end of the ground wire through the inside of the wire coating. If there is an electronic control unit at the terminal on the opposite side of the ground connection terminal, if moisture penetrates from the terminal of the grounding wire to the inside of the wire coating, it will corrode or the electronic control unit Moisture may reach the surface and prevent normal operation. Therefore, it is necessary to perform a sealing process in order to waterproof and stop the terminal portion of the ground wire.

  As a sealing process applied to the end portion of the grounding wire, the first sealing agent and the second sealing agent having two different viscosities are used to cover the bare wire conductor at the end of the grounding wire. A sealing process has been proposed in which a sealing agent is provided, and a second sealing agent is provided so as to cover the first sealing agent, thereby waterproofing / water-stopping the connection portion between the ground wire and the ground connection terminal (for example, , See Patent Document 1).

  However, the sealing process disclosed in the cited document 1 has a problem due to the use of two different materials as the sealing agent (sealing agent). For example, since materials having two different viscosities are used as the sealant, different operations must be performed when using each sealant, resulting in poor workability. Further, since two different materials are used as the sealing agent, the material characteristics are different between a single sealing agent and a portion where different sealing agents are applied. Moreover, it is necessary to change a nozzle and a syringe for every different material, and the usage-amount of a nozzle and a syringe will increase.

International Publication No. 2007/013589

  This invention is made | formed in view of the said situation, Comprising: It aims at providing the electric wire terminal part sealing processing method of waterproofing / water-stopping an electric wire terminal part using one type of material which can adjust a viscosity. .

According to one aspect of the present invention, a step of preparing an electric wire in which a bare wire conductor is covered with an insulating member and a connection terminal, and connecting the bare wire conductor at the end of the electric wire so that the connection terminal is conducted, and a bare wire conductor; Supplying a sealing agent whose viscosity changes due to a temperature change to the connection part between the first and second connection terminals in a first viscosity state, curing the sealing agent supplied in the first viscosity state, and the viscosity from the first viscosity state. and adjusting the viscosity of the sealant such that the higher the second viscosity state, in order to fill the sealant of the second viscosity state between between the connection terminal and the bare conductor and bare wire conductors, bare wire The gist of the present invention is to provide a method for sealing an end of an electric wire including a step of supplying a sealant in the second viscosity state from the vicinity of the tip of the conductor and curing the sealant supplied in the second viscosity state.

  ADVANTAGE OF THE INVENTION According to this invention, the electric wire terminal part sealing processing method of waterproofing / water-stopping an electric wire terminal part using one type of material which can adjust a viscosity can be provided.

It is a perspective view of the electric wire terminal part processed with the electric wire terminal part sealing processing method which concerns on embodiment of this invention. It is a side view of the electric wire terminal part processed with the electric wire terminal part sealing processing method which concerns on embodiment of this invention. It is a graph which shows the temperature dependence of the viscosity of sealing agent. It is a flowchart which shows the electric wire terminal part sealing processing method which concerns on embodiment of this invention. It is a viscosity characteristic table | surface which shows the viscosity characteristic of the sealing agent used for an Example. It is a table | surface which shows the performance evaluation result which examined the performance of the electric wire in the Example.

  Embodiments of the present invention will be described below with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, the drawings are schematic, and the relationship between the thickness and the planar dimensions, the ratio of the thickness of each layer, and the like are different from the actual ones. Therefore, specific thicknesses and dimensions should be determined in light of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

(Embodiment)
As shown in FIGS. 1 and 2, the wire terminal portion according to the embodiment of the present invention is connected so that the bare wire conductor 21 at the terminal portion of the wire 20 and the connection terminal 10 are electrically connected. The connecting portion between the bare wire conductor 21 and the connection terminal 10 is subjected to a sealing process for waterproofing and water-stopping with a sealing agent. Details of this sealing processing method will be described later.

  The electric wire 20 includes a bare wire conductor 21 made of copper (Cu), aluminum (Al), and tin (Sn) and an insulating member 22 that covers the outer periphery of the bare wire conductor 21 with a resin or the like. The terminal portion of the electric wire 20 is in a state where the bare wire conductor 21 is exposed to connect the connection terminal 10.

  The connection terminal 10 is provided with a conductor crimping portion 11 and a sheath crimping portion 12 having a U-shaped cross section. The connection terminal 10 and the electric wire 20 are connected by crimping the bare wire conductor 21 with the conductor crimping portion 11 and crimping the insulating member 22 with the covering crimping portion 12.

The sealant (not shown) is a material that has fluidity and decreases in viscosity when heated. The state ( second viscosity state ) of the sealant for increasing the surface of the connection part is preferably 3500 mPa · s or more, and more preferably 3500 to 4000 mPa · s. In addition, the state of the sealant ( first viscosity state ) for filling between the bare wire conductor 21 and the connection terminal 10 and between the bare wire conductors 21 by capillary action is preferably 2000 mPa · s or less. More preferably, it is -2000 mPa * s.

As an example of the temperature dependency of the viscosity of the sealant, a viscosity-temperature dependency graph using Chemitech U.S.C. as a sealant A is shown in FIG. As can be seen from the graph in FIG. 3, the viscosity at a temperature of 10 ° C. is about 11000 mPa · s, which is too high compared to the second viscosity state . The viscosity when the temperature is 20 ° C. is about 5000 mPa · s, which is still higher than the second viscosity state . The viscosity when the temperature is 25 ° C. is about 4000 mPa · s, which is suitable for the second viscosity state . The viscosity when the temperature is 30 ° C. is about 3000 mPa · s, which is between the first viscosity state and the second viscosity state. The viscosity when the temperature is 40 ° C. is about 1800 mPa · s, which is suitable for the first viscosity state . Therefore, when using Chemitech Co., Ltd.'s Keshmir U-485D as the sealant, the sealant is 25 ° C. to obtain the second viscosity state , and the sealant is 40 ° C. to obtain the first viscosity state. To.

  In addition, a material that is rapidly cured by a chemical change is used for the sealant. As a material that is rapidly cured by a chemical change, a photocurable resin that is cured by irradiation with ultraviolet rays or the like is employed.

  Furthermore, a material having a composite curing function can be used as the sealant. Examples of the sealant having a composite curing function include a photocurable anaerobic curable adhesive, a photocurable thermosetting adhesive, and a photocurable moisture curable adhesive. The photocurable anaerobic curable adhesive is not only a photocuring property but also a sealant that is not cured while being exposed to air but is cured by blocking air. A photocurable thermosetting adhesive is a sealant that cures not only by photocuring properties but also by a chemical reaction caused by heat. The photocurable moisture curable adhesive is not only a photocurable property but also a sealant that is cured by a chemical reaction with moisture in the air. In other words, photocurable anaerobic curable adhesives, photocurable thermosetting adhesives, and photocurable moisture curable adhesives have curing characteristics even in shadows (parts not exposed to light). Excellent.

  As the sealant, an adhesive having a composite curing function mainly composed of modified acrylate, cationic epoxy, epoxy, urethane acrylate, olefin acrylate, acrylic, cationic epoxy + acrylic, silicone resin or the like is preferable.

  Below, the electric wire terminal part sealing processing method which concerns on embodiment of this invention is demonstrated, referring the flowchart of FIG.

  (A) First, in step S10, the electric wire 20 and the connection terminal 10 in which the bare wire conductor 21 is covered with the insulating member 22 are prepared, and connected so that the bare wire conductor 21 and the connection terminal 10 at the terminal portion of the electric wire 20 are electrically connected. To do. Specifically, the bare wire conductor 21 is crimped by the conductor crimping portion 11 and the conductor crimping portion 11 and the bare wire conductor 21 are electrically connected, so that the electric wire 20 and the connection terminal 10 are electrically connected. Connect.

(B) Next, in step S11, the supply connection between the connection terminal 10 and the bare conductor 21 sealant viscosity is changed by temperature change (process A portion shown in FIG. 1) in a first viscosity state . The supplied sealant in the first viscosity state permeates between the bare wire conductor 21 and the connection terminal 10 and between the bare wire conductors 21 by a capillary phenomenon. Thereafter, the sealant supplied in the first viscosity state is cured. The sealant whose viscosity changes here is a sealant whose viscosity is 3500 to 4000 mPa · s at 25 ° C. and 1500 to 2000 mPa · s at 40 ° C. The sealant in the first viscosity state is a sealant having a viscosity of 1500 to 2000 mPa · s. As a method of curing the sealant in the first viscosity state, a method corresponding to the curing method of the sealant to be used is appropriately selected from the above-described various sealants.

(C) Next, in step S12, the viscosity of the sealant is adjusted so that the second viscosity state is lower than the first viscosity state. The sealant in the second viscosity state is a sealant having a viscosity of 3500 to 4000 mPa · s. The sealant adjusts the viscosity by heating or cooling a sealed container such as a syringe. Here, as a method of heating a container such as a syringe, a heating element (linear, planar, hot water, etc.) is attached to the container and heated to the target 40 ° C.

(D) Next, in step S13, in order to fill the sealant in the second viscosity state between the bare wire conductor 21 and the connection terminal 10 and between the bare wire conductors 21, the vicinity of the tip of the bare wire conductor 21 ( It supplies with the sealing agent of a 2nd viscosity state from the process B location shown in FIG. 1, and hardens the sealing agent supplied with the 2nd viscosity state . The method of curing the sealant in the second viscosity state is the same method as when the sealant in the first viscosity state is cured.

  (E) Next, in step S <b> 14, it is determined whether or not the sealing agent is to be overcoated on the terminal portion of the electric wire 20. When it is determined that the sealant is to be overcoated, the process proceeds to step S11. On the other hand, when it is determined that the sealing agent is not overcoated, the wire terminal portion sealing process is terminated.

  According to the electric wire terminal part sealing treatment method according to the embodiment of the present invention, since only one kind of material is used as the sealant, there is no need to change the operation of curing the sealant, And since it is not necessary to change the nozzle and syringe used for supply of sealing agent, work efficiency can be improved and cost can be reduced.

  Moreover, according to the electric wire terminal part sealing processing method which concerns on embodiment of this invention, since only one type of material is used as a sealing agent, it seals, without changing material characteristics other than a viscosity characteristic It becomes possible to process.

( Reference examples and examples)
Reference examples and examples of the present invention will be described below with reference to FIGS.

  FIG. 5 shows a viscosity characteristic table of the sealant used in the examples. Chemitech's Keshmir U-485D (sealing agent A) has a viscosity of 3500 to 4000 mPa · s when the temperature is 25 ° C. Chemitech's Keshmir U-485D (sealing agent A ') has a viscosity of 1500 to 2000 mPa · s when the temperature is 40 ° C. Chemitech's Keshimir U-485 (sealant B) has a viscosity of 6500-7500 mPa · s when the temperature is 25 ° C. Chemitech's Keshmir U-483B (sealing agent A) has a viscosity of 1000 mPa · s when the temperature is 25 ° C. In addition, the sealing agent a has a viscosity of 15 to 500 mPa · s when the temperature is 25 ° C. The sealant b has a viscosity of 1000 to 5000 mPa · s when the temperature is 25 ° C.

  In FIG. 6, the evaluation of workability is evaluated as “◯” when it is better than the conventional example, and “X” when it is worse than the conventional example. The cost is evaluated as “◯” when it is better than the conventional example, and as “X” when it is worse than the conventional example. The evaluation of water stoppage as durability is evaluated as “◯” when it is 200 kPa or higher in a salt spray test (35 ° C. NaCl 5% × 96 hours), and “X” when it is lower than 200 kPa. . Evaluation of contact resistance as durability was evaluated in a salt spray test (35 ° C NaCl 5% x 96 hours) when there was no increase in resistance of 1 mΩ or more, and when there was an increase in resistance of 1 mΩ or more Is evaluated as “×”. The housing insertability is evaluated as “◯” when the connection terminal 10 enters the connection target, and “X” when the connection terminal 10 does not enter. Since unimplemented ones are unknown, they are indicated by “−”.

( Reference Example 1 )
The reference example 1 uses the sealing agent A (Keshmir U-485D of Chemtech Co., Ltd.) shown in FIG. 5 as the first and second sealing agents.

An electric wire 20 having a conductor cross-sectional area of 0.75 ^-3 mm ² of the bare wire conductor 21 is crimped to the connection terminal 10, and the connection portion between the bare wire conductor 21 and the connection terminal 10 (process A location shown in FIG. 1) 15 milligrams of the sealing agent A is dropped as 1 sealing agent, and the sealing agent A as the first sealing agent is cured. Thereafter, 2 milligrams of the same sealant A as the second sealant is dropped near the tip of the bare wire conductor 21 (process B location shown in FIG. 1), and sealed as the second sealant. Stop agent A is cured. The ultraviolet irradiation condition was 750 mW / cm ² × 5 seconds.

  As a result, as shown in FIG. 6, the evaluation of workability and cost is a “◯” evaluation. However, the evaluation of the contact resistance as durability was “x” evaluation because there was a resistance increase of 1 mΩ or more. Moreover, the evaluation of the housing insertion property was also “x” evaluation. Therefore, in Example 1 using the sealant having the same viscosity as the first sealant and the second sealant, the performance was not satisfied. In addition, the evaluation of the water stop as durability has not been performed and is not evaluated.

( Reference Example 2 )
Reference Example 2 uses sealant C (Kesimir U-483B from Chemtech Co., Ltd.) shown in FIG. 5 as the first sealant, and sealant B (Kesimir from Chemtech Co., Ltd.) as the second sealant. U-485) is used.

An electric wire 20 having a conductor cross-sectional area of 0.75 ^-3 mm ² of the bare wire conductor 21 is crimped to the connection terminal 10, and the connection portion between the bare wire conductor 21 and the connection terminal 10 (process A location shown in FIG. 1) 15 milligrams of the sealing agent C is dropped as 1 sealing agent, and the sealing agent C as the first sealing agent is cured. Then, 2 milligrams of the sealing agent B as the second sealing agent is dropped on the vicinity of the tip of the bare wire conductor 21 (the processing B position shown in FIG. 1), and the sealing agent B as the second sealing agent is added. Harden. The ultraviolet irradiation condition was 750 mW / cm ² × 5 seconds.

  As a result, as shown in FIG. 6, the evaluation of workability and cost is “x” evaluation. The evaluation of the contact resistance as durability was also “x” evaluation because there was a resistance increase of 1 mΩ or more. Moreover, the evaluation of the housing insertion property was also “x” evaluation. Therefore, in Example 2 in which the sealant C was used as the first sealant and the sealant B was used as the second sealant, the performance was not satisfied. In addition, the evaluation of the water stop as durability has not been performed and is not evaluated.

( Reference Example 3 )
The reference example 3 uses the sealing agent C (Keshmir U-483B of Chemtech Co., Ltd.) shown in FIG. 5 as the first and second sealing agents.

An electric wire 20 having a conductor cross-sectional area of 0.75 ^-3 mm ² of the bare wire conductor 21 is crimped to the connection terminal 10, and the connection portion between the bare wire conductor 21 and the connection terminal 10 (process A location shown in FIG. 1) 15 milligrams of the sealing agent C is dropped as 1 sealing agent, and the sealing agent C as the first sealing agent is cured. Thereafter, 2 milligrams of the same sealant C as the second sealant is dropped to the vicinity of the tip of the bare wire conductor 21 (process B position shown in FIG. 1), and the seal as the second sealant is sealed. The stopper C is cured. The ultraviolet irradiation condition was 750 mW / cm ² × 5 seconds.

  As a result, as shown in FIG. 6, the evaluation of workability and cost is a “◯” evaluation. However, the evaluation of the contact resistance as durability was “x” evaluation because there was a resistance increase of 1 mΩ or more. The evaluation of the housing insertability was a “◯” evaluation. Therefore, in Example 3 in which the sealant having the same viscosity was used for the first sealant and the second sealant, the performance was not satisfied. In addition, the evaluation of the water stop as durability has not been performed and is not evaluated.

( Example )
The Example of this invention uses sealing agent A '(Keshmir U-485D of Chemtech Co., Ltd.) shown in FIG. 5 as the first sealing agent, and sealing agent A (Chemtech stock) as the second sealing agent. Company Keshimir U-485D) is used.

An electric wire 20 having a conductor cross-sectional area of 0.75 ^-3 mm ² of the bare wire conductor 21 is crimped to the connection terminal 10, and the connection portion between the bare wire conductor 21 and the connection terminal 10 (process A location shown in FIG. 1) 15 milligrams of the sealing agent A ′ as 1 sealing agent is dropped to cure the sealing agent A ′ as the first sealing agent. Thereafter, 2 milligrams of the sealing agent A as the second sealing agent is dropped on the vicinity of the tip of the bare wire conductor 21 (process B location shown in FIG. 1), and the sealing agent A as the second sealing agent is added. Harden. The ultraviolet irradiation condition was 750 mW / cm ² × 5 seconds.

  As a result, as shown in FIG. 6, the evaluation of workability and cost is a “◯” evaluation. The evaluation of the contact resistance as durability was also a “◯” evaluation with no resistance increase of 1 mΩ or more. The evaluation of housing insertability was also “◯”. Therefore, Example 4 in which the sealant A ′ was used as the first sealant and the sealant A was used as the second sealant satisfied the performance. In addition, the evaluation of the water stop as durability has not been performed and is not evaluated.

(Conventional example)
The conventional example as a comparative example uses the sealant a shown in FIG. 5 as the first sealant and the sealant b as the second sealant.

An electric wire 20 having a conductor cross-sectional area of 0.75 ^-3 mm ² of the bare wire conductor 21 is crimped to the connection terminal 10, and the connection portion between the bare wire conductor 21 and the connection terminal 10 (process A location shown in FIG. 1) 15 milligrams of the sealing agent a is dropped as 1 sealing agent, and the sealing agent a as the first sealing agent is cured. Thereafter, 2 milligrams of the sealing agent b as the second sealing agent is dropped near the tip of the bare wire conductor 21 (the treatment B location shown in FIG. 1), and the sealing agent b as the second sealing agent is added. Harden. The ultraviolet irradiation condition was 750 mW / cm ² × 5 seconds.

  As a result, as shown in FIG. 6, the evaluation of workability and cost is “x” evaluation. The evaluation of water stoppage as durability was a “◯” evaluation. In addition, evaluation of contact resistance as durability and evaluation of housing insertability have not been performed and are not evaluated.

(Other embodiments)
As described above, the present invention has been described according to the embodiment. However, it should not be understood that the description and drawings constituting a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques should be apparent to those skilled in the art.

  For example, as the sealant in the embodiment, the sealant that is in the first viscosity state at 20 ° C. and is in the second viscosity state at 40 ° C. is described as an example, but is not limited to these temperatures, It may be a sealant that becomes the first viscosity state at 10 ° C. and becomes the second viscosity state at 20 ° C. That is, the sealant is not limited by the temperature used but is defined by the viscosity.

  Thus, it should be understood that the present invention includes various embodiments and the like not described herein. Therefore, the present invention is limited only by the invention specifying matters in the scope of claims reasonable from this disclosure.

DESCRIPTION OF SYMBOLS 10 ... Connection terminal 11 ... Conductor crimping part 12 ... Cover crimping part 20 ... Electric wire 21 ... Bare wire conductor 22 ... Insulating member

Claims (7)

Preparing a wire and a connection terminal covering a bare wire conductor with an insulating member, and connecting the bare wire conductor and the connection terminal at a terminal portion of the wire so as to be conductive;
Supplying a sealant whose viscosity changes due to a temperature change to a connection portion between the bare wire conductor and the connection terminal in a first viscosity state, and curing the sealant supplied in the first viscosity state;
Adjusting the viscosity of the sealant so that the second viscosity state is higher than the first viscosity state;
In order to fill the sealant in the second viscosity state between the bare wire conductor and the connection terminal and between the bare wire conductors, the sealing in the second viscosity state is made from the vicinity of the end of the bare wire conductor. Supplying the sealing agent supplied in the second viscosity state and curing the sealing agent supplied in the second viscosity state. The wire terminal portion sealing treatment method according to claim 1, wherein the first viscosity state is 2000 mPa · s or less , and the second viscosity state is 3500 mPa · s or more .   The step of curing the sealant in the first viscosity state, the step of adjusting the viscosity of the sealant, and the step of curing the sealant in the second viscosity state are repeated in order. The electric wire terminal part sealing processing method of Claim 1 or 2.   The electric wire terminal part sealing treatment method according to any one of claims 1 to 3, wherein the sealant is rapidly cured by a chemical change.   The electric wire terminal part sealing treatment method according to claim 1, wherein the sealant has a composite curing function.   The sealant having the composite curing function is any one of a photocurable anaerobic curable adhesive, a photocurable thermosetting adhesive, and a photocurable moisture curable adhesive. Item 6. A method for sealing an end of an electric wire according to Item 5.   The sealing agent having the composite curing function is mainly composed of any one of modified acrylate, cationic epoxy, epoxy, urethane acrylate, olefin acrylate, acrylic, cationic epoxy + acryl, and silicone resin. The electric wire terminal part sealing processing method of 5 or 6.

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