JP2008053015A - Penetration enhancement method of waterproof agent, penetration inspection method of waterproof agent, and waterproof treatment method of wire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a penetration enhancement method of a waterproof agent capable of enhancing penetration of a penetrant when the waterproof agent is made to penetrate between cores of a covered wire. <P>SOLUTION: This method is used for making a waterproof agent 17 penetrate between cores of a wire 11 formed by covering a plurality of cores 12. In the method, the surface temperature of the cover 13 of the wire 11 is heated above 50°C to aid expansion of the cover in making the waterproof agent penetrate into the wire 11 to provide the effect of penetration enhancement of the waterproof agent, and thereby the penetration of the penetrant is enhanced in making the waterproof agent penetrate between the cores of the covered wire. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a waterproofing agent penetration promoting method, a waterproofing agent penetration inspection method, and a wire waterproofing method, in particular, by allowing a waterproofing agent to permeate from a connection portion with a connection terminal of an electric wire constituting a wire harness or the like.

  Conventionally, the water sucked up from the crimping part of the grounding terminal attached outside the wire harness in an automobile has soaked from between the core wires of the electric wire and reaches the connector (connecting part) or auxiliary machine, etc. In order to deal with problems that cause various problems, a waterproofing agent is filled between the cores of the electric wires to prevent water transmitted between the cores.

  As such a waterproofing method, at least one end of a covered electric wire with exposed conductor ends at both ends is embedded and held in a waterproof insulating shielding agent, and air is sucked from the other end of the covered electric wire to A waterproofing method (for example, refer to Patent Document 1) or a grounding wire that is sealed by sucking and filling a shield agent between conductor wires under a negative pressure to form a waterproof wire having a hermetically sealed conductor by the shield agent. In the treatment, a water-stopping agent having fluidity is supplied to one terminal, and during or after the supply of the water-stopping agent, the other end of the grounding wire is provided inside the covering material of the grounding wire. A water-stopping treatment method (for example, see Patent Document 2) in which a water-stopping agent permeates the inside of a covering material by sucking air and reducing the pressure has been proposed.

In addition, as a method for inspecting the sealing property by penetration of waterproofing agent, an air tube is connected to the end of the covered electric wire with the intermediate joint as a joint and its vicinity covered with a waterproof material, and covered with a vacuum pump. The inside of the covering portion of the electric wire is evacuated, and the waterproof material is adsorbed to the intermediate joint portion and its vicinity by the negative pressure generated by evacuation. There is an inspection method in which the degree of vacuum at the time of evacuation is detected by a pressure sensor to determine whether the seal state of the intermediate joint portion is good or bad (for example, see Patent Document 3). There is also a method called a submergence test in which pressure is applied from the other end of the waterproof portion and the water stop portion is submerged in water to check whether bubbles are generated.
JP-A-6-84416 (2 pages, FIG. 1) Japanese Patent Laying-Open No. 2004-355851 (page 4-5, FIG. 2) JP 2004-158444 A (page 7-8, FIG. 6)

  However, the method of sucking the waterproofing agent between the core wires by the negative pressure as disclosed in Patent Document 1 and Patent Document 2, etc., when the wire length is long, even when sucking from between the core wires, when passing between the core wires Since the resistance is large, the force that can actually be sucked is very small. This is also clear from the fact that there is almost no air flow even though the pressure has reached the desired negative pressure.

  For example, when the pressure between the core wires of the AVSS 0.5 wire is sucked from one end with a negative pressure of -70 kPa and the pressure is measured without supplying a waterproofing agent to the other end, the wire length is -70 kPa for both 200 mm and 2000 mm. However, the flow rate at this time is greatly different from 2.5 ml / min when the wire length is 150 mm, and 0.6 ml / min when the wire length is 1500 mm, and the actual suction force is very small.

  In addition, if the method of inspecting the degree of vacuum when negative pressure is applied is the method described in Patent Document 3, since the degree of vacuum is easily generated, the reliability is low and the waterproof agent penetrates to a certain extent. It is unknown whether it is. In addition, the submergence test is not only unknown to the extent that the waterproofing agent has penetrated, but is also a destructive test that works to remove the penetrated waterproofing agent from the penetration part, and cannot be employed in product testing.

  Furthermore, in order to obtain a reliable sealing property must not surely waterproofing agent penetration, sealing performance, whether how far waterproofing agent because it is determined by the permeated length of waterproofing agent is permeated from the outside There is a strong demand for a non-destructive confirmation method.

  The present invention has been made in view of the above points, and a method for promoting penetration of a waterproofing agent and a degree of penetration of the waterproofing agent to promote penetration of the penetrating agent when the waterproofing agent penetrates between core wires of a covered electric wire. An object of the present invention is to provide a method of inspecting a waterproofing agent that can be confirmed from the outside by non-destructive inspection.

  In order to achieve the above object, a waterproofing agent penetration promoting method according to claim 1 of the present invention is a method of infiltrating a waterproofing agent between the core wires of an electric wire coated with a plurality of core wires, and covering the electric wire Is characterized by heating the surface temperature to 50 ° C. or higher.

  By heating the coating of the electric wire at a temperature of 50 ° C. or higher that does not damage the coating, the flexibility of the coating is increased and the coating is easily expanded. Moreover, since a waterproofing agent also warms, a viscosity falls and it becomes easy to osmose | permeate. And a waterproofing agent osmose | permeates by the capillary phenomenon in the clearance gap between the core wires of an electric wire, and the clearance gap between a core wire and a coating | cover. At this time, since the coating has flexibility, it easily expands, and the waterproofing agent easily and well penetrates where the gaps between the core wires and the gap between the core wires and the coating spread. . Then, after the waterproofing agent penetrates, the temperature of the coating decreases and shrinks, and the waterproofing agent is tightened. Thereby, the waterproof performance of the electric wire by a waterproofing agent improves.

  The waterproofing agent penetration promoting method according to claim 2 of the present invention is the waterproofing agent penetration promoting method according to claim 1, wherein the waterproofing agent penetrates from one end of the wire and sucks from the other end. It is characterized in that the internal pressure of the electric wire is less than the external pressure.

  Air inside the electric wire is sucked from the other end of the electric wire, and the internal pressure of the electric wire is set to a negative pressure lower than the external atmospheric pressure, so that the penetration of the waterproofing agent from the one end into the electric wire is further facilitated.

  Further, the waterproofing agent penetration promoting method according to claim 3 of the present invention is the waterproofing agent penetration promoting method according to claim 1 or claim 2, wherein the place where the waterproofing agent penetrates is preliminarily arranged between the electric wire and another method. It is the part which connected the conductor.

  The waterproofing agent is infiltrated from a portion where the core wire of the electric wire is connected to another conductor such as a connection terminal. In this case, when the connection terminal and the core wire are crimped and connected, the waterproofing agent is infiltrated into the electric wire from the crimping connection portion to stop water.

  In the waterproof agent penetration inspection method according to claim 4 of the present invention, the waterproof agent is infiltrated between the core wires of the electric wires coated with a plurality of core wires, and the penetration degree of the waterproof agent is determined from the change in the outer diameter of the electric wires. It is characterized by inspecting.

  When the waterproofing agent penetrates into the gap between the core wires of the electric wire, the outer diameter dimension of the electric wire coating becomes larger (thick). Therefore, the outer diameter before infiltrating the waterproofing agent of the electric wire and the outer diameter after infiltrating the waterproofing agent can be measured, and the degree of penetration of the waterproofing agent can be confirmed from the change in the outer diameter of the electric wire.

  The waterproofing agent penetration inspection method according to claim 5 of the present invention is characterized in that, in the waterproofing agent penetration inspection method according to claim 4, the change in the outer diameter of the electric wire is inspected by a dimension measuring instrument. Yes.

  The change in the outer diameter of the wire is accurately measured with a dimension measuring instrument. In this case, if a digital dimension measuring instrument is used as the dimension measuring instrument, the dimension measurement is easy. Then, the penetration degree of the waterproofing agent into the electric wire is inspected and confirmed from the outer diameter change.

  In the waterproof agent penetration inspection method according to claim 6 of the present invention, the waterproof agent is infiltrated between the core wires of an electric wire covered with a plurality of core wires, and the penetration of the waterproof agent is determined based on the amount of change in the outer diameter of the electric wire. It is characterized by examining the amount and penetration distance.

  When the waterproofing agent penetrates into the gap between the core wires of the electric wire, the outer diameter dimension of the electric wire coating becomes larger (thick). Therefore, the outer diameter before infiltrating the waterproofing agent of the wire and the outer diameter after infiltrating the waterproofing agent are measured, and the amount of penetration of the waterproofing agent and the location where the waterproofing agent is supplied from the amount of change in the outer diameter of the wire Inspect and confirm the penetration distance. Thereby, the maximum sealing pressure resistance of the product can be predicted in a non-destructive manner.

  The waterproofing agent penetration test method according to claim 7 of the present invention is the waterproofing agent penetration test method according to claim 6, wherein the amount of change in the outer diameter of the electric wire uses two or more dimension measuring instruments. The penetration distance of the waterproofing agent is inspected by measuring the outer diameter of two or more locations in the length direction of the electric wire.

The penetration distance of the waterproofing agent is inspected by measuring two or more outer diameters in the length direction of the electric wire using two or more dimension measuring instruments. For example, when the required penetration length is A mm, the dimension measuring device is arranged at the A mm position and the B (> A) mm position. Although it depends on the viscosity of the waterproofing agent, the outer diameter of the Amm position changes within a predetermined time t ₁ seconds after dropping the waterproofing agent such as a silicone adhesive, and the outside of the Bmm position within a predetermined time t ₂ (> t ₁ ) seconds. If the diameter changes, it will be accepted. If more time is required, it means that the waterproofing agent has deteriorated and the viscosity is high, and if the Bmm position swells but the Amm position does not swell, the waterproofing agent is the core wire. This means that it has not penetrated the entire cross section of the gap between them, but has penetrated only to a part of the path to the Bmm position.

  Further, the waterproofing agent penetration inspection method according to claim 8 of the present invention allows the waterproofing agent to penetrate between the cores of the electric wires by the waterproofing agent penetration promoting method according to any one of claims 1 to 3. The waterproofing treatment is performed, and the penetration degree is inspected by the waterproofing agent penetration inspection method according to any one of claims 4 to 7.

  The wire coating is heated at a temperature of 50 ° C. or higher so as not to damage the coating, thereby increasing the flexibility of the coating to facilitate expansion, and the gap between the core wires of the wire and the gap between the core wires and the coating are waterproofed by capillary action. Measures the outer diameter before infiltrating the waterproofing agent of the wire and the outer diameter after infiltrating the waterproofing agent and infiltrates the waterproofing agent from the amount of change in the outer diameter of the wire. Inspect and confirm the degree. Thereby, the maximum sealing pressure resistance of the product can be predicted in a non-destructive manner.

  According to the present invention, when the waterproofing agent is infiltrated between the core wires of the covered electric wire, the electric wire coating is softened by warming the electric wire, and the force for expanding the electric wire covering can be reduced. Moreover, a waterproofing agent will also be warmed by warming an electric wire coating | cover, and since a viscosity falls by heating a general waterproofing agent, it will become easy to osmose | permeate. In addition, the waterproofing performance is improved because the covering contracts and tightens the waterproofing agent after the wire covering expands and the gap between the core wires and the gap between the core wire and the covering spreads, and then the covering contracts and tightens the waterproofing agent.

  Further, the penetration of the waterproofing agent can be inspected and confirmed from the outside without destruction. Moreover, it can be easily confirmed how far the waterproof agent has penetrated by measuring the position where the wire coating is enlarged (thick) from the location where the waterproof agent has penetrated. Further, since the penetration distance of the waterproofing agent can be known from the outside, the maximum seal pressure resistance of the product can be predicted nondestructively.

  Hereinafter, the best embodiment of the present invention will be described in detail with reference to the drawings. In the present invention, when a waterproofing agent is permeated into the gap between the core wires and the gap between the coating and the core wire from the end of the covered electric wire coated with a plurality of core wires using the capillary phenomenon (capillary phenomenon), It is intended to promote penetration. Further, a change in the outer diameter of the electric wire due to the expansion of the coating after the waterproofing agent has penetrated into the electric wire is detected, and the penetration degree of the waterproofing agent is confirmed nondestructively.

  As is well known, capillary action is a phenomenon in which when a very thin tube (meniscus tube) is placed vertically in a container filled with liquid, the water level in the tube rises or falls below the liquid level outside the tube. The liquid level in the tube rises when the liquid has a contact angle smaller (wet) than a right angle (for example, water against glass). As shown in FIG. 1, the height of the liquid level in the narrow tube 1 is H, the surface tension of the liquid 2 is γ, the contact angle between the thin tube 1 and the liquid 2 is θ, the density of the liquid 2 is ρ, and gravity. When acceleration is g and the radius of the narrow tube 1 is r, it is expressed by H = 2 × γ × cos θ / (ρ × g × r). Further, the pressure p generated in the narrow tube 1 at this time is represented by p = ρ × g × H.

  For example, the height H of the silicone as a waterproofing agent that penetrates into the gap of 1 μm is 3.9 m, and the penetration pressure p at this time reaches 38 kPa. Therefore, when a waterproofing agent is infiltrated using a capillary phenomenon between a plurality of core wires of a covered electric wire, the electric wire coating expands due to the pressure p, and the pressure in the coating decreases and stabilizes due to the expansion.

  FIG. 2 shows a water stop treatment apparatus for electric wires for carrying out the waterproofing agent promotion method and waterproofing agent penetration test method according to the present invention. As shown in FIG. 3, the electric wire 11 is a covered electric wire in which a plurality of core wires (element wires) 12 are covered with an insulating coating 13. As shown in FIG. 2, the coating 13 on one side end portion 11 a of the electric wire 11 is peeled off. The core wire 12 is taken and crimped to another conductor, for example, the crimping portion 14a of the connection terminal 14, and is electrically and mechanically connected. The other end 11 b of the electric wire 11 is connected to the suction device 15.

  A waterproofing agent feeder 16 is disposed above the crimping portion 14a of the connection terminal 14, and a liquid waterproofing agent (waterproofing agent) 17 is supplied to the crimping portion 14a. An example of the waterproofing agent is Shin-Etsu Silicone Silicone Adhesive (KE3420). Further, a heat source 18 for warming the coating 13 is disposed at a position below the electric wire 11 in the vicinity of supplying the waterproofing agent 17. An example of the heat source 18 is an infrared heater. The heat source 18 warms the coating 13 with an amount of heat that does not damage the coating 13, and makes the coating 13 flexible so that it can easily expand.

  In addition, a dimension measuring device, for example, a digital dimension measuring device 19 is arranged at a position directly above the electric wire 11 in the vicinity of supplying the waterproofing agent 17, for example, a position directly above the heat source 18. The digital dimension measuring device 19 measures the outer diameter of the covering 13 of the electric wire 11 and detects the degree of penetration of the waterproofing agent 17 into the electric wire 11.

The operation will be described below. First, the outer diameter of the electric wire 11, that is, the outer diameter D ₁ of the coating 13 is measured in advance by the digital dimension measuring device 19 (FIG. 3). Further, the heat source 18 is used to heat the electric wire 11 with a heat amount that does not damage the coating 13 so that the coating 13 has flexibility. Next, the suction device 15 sucks from the other end portion 11b of the electric wire 11 so that the inner pressure of the electric wire 11 is less than the external pressure (negative pressure), and the crimping of the connection terminal 14 is crimped and connected to the one end portion 11a of the electric wire 11. A liquid waterproofing agent 17 is supplied from the waterproofing agent supply machine 16 to the unit 14a.

  Although the waterproofing agent 17 will also be warmed by warming the coating | cover 13, since the viscosity falls by the said waterproofing agent 17 being heated, it becomes easy to osmose | permeate. And the waterproofing agent 17 osmose | permeates to the clearance gap between the core wires 12 of the electric wire 11, and the clearance gap between the core wires 12 and the coating | cover 13 as shown in FIG. At this time, since the covering 13 has flexibility, it easily expands, and the waterproofing agent 17 easily penetrates where the gaps between the core wires 12 and the gaps between the core wires 12 and the covering 13 are widened. To go. Then, after the waterproofing agent 17 has permeated, the temperature of the coating 13 decreases and shrinks, and the waterproofing agent 17 is tightened. Thereby, waterproof performance improves.

After infiltrating the waterproofing agent 17, the outer diameter of the electric wire 11, that is, the outer diameter D ₂ of the coating 13 is measured again by the digital dimension measuring device 19, and the change amount δ (= D ₂ −D ₁ ) is detected. Then, it is inspected from which position of the electric wire 11 the penetration of the waterproofing agent 17 from the crimping portion 14a (the supply position of the waterproofing agent 17) (the degree of penetration) by the detected outer diameter change amount.

  The outer diameter change amount of the electric wire 11 varies depending on the wire diameter of the electric wire and the material of the coating, but the outer diameter change amount is about 5 μm for AVSS2.0F, about 1 μm for AVSS0.5 and about 1 μm for AEX1.25. Increased by 1 μm.

  Further, the penetration amount of the waterproofing agent 17 and the penetration distance from the crimping portion 14a (the supply position of the waterproofing agent 17) are inspected from the outer diameter change amount of the coating 13. In this case, the penetration distance of the waterproofing agent 17 is inspected by measuring two or more outer diameters in the length direction of the electric wire 11 using two or more digital dimension measuring instruments 19.

For example, when the required permeation length is 10 mm, outer diameter measuring instruments are arranged at the 5 mm position and the 10 mm position. Although it depends on the viscosity of the waterproofing agent, in the case of the silicone adhesive (KE3420 made by Shin-Etsu Silicone, viscosity 600 mPa ^* s) as an example, the outer diameter at the 5 mm position changes within 0.1 seconds after the waterproofing agent is dropped. If the outer diameter at the 10 mm position changes within 0.2 seconds, the test was accepted.

  When more time is required, it means that the waterproofing agent (silicone adhesive) has deteriorated and the viscosity is increased. In addition, when the 10 mm position swells but the 5 mm position does not swell, the waterproofing agent (silicone adhesive) does not reach the entire cross section of the gap between the core wires, but penetrates only through a part of the path to the 10 mm position. In that case, the water stoppage performance was not sufficient, so it was regarded as defective.

  Next, the water stop performance in the method for promoting penetration of the waterproofing agent will be described with reference to examples.

(1) Shin-Etsu Silicone silicone adhesive (KE3420) was used as a waterproofing agent (waterproofing material).
(2) The heating temperature of the wire coating was set to 0 ° C, 20 ° C, 30 ° C, 50 ° C, 80 ° C, and 120 ° C.
(3) The evaluation method uses an internal pressure at which air is blown from the other end of the wire and air leaks from the water-stopping portion of a sample in which a waterproof agent is sufficiently sucked into the terminal of various sizes using a capillary phenomenon and sufficiently cured. Was measured, and 50 kPa or more was regarded as acceptable.
(4) The presence / absence of air leakage was determined to be leaked when the evaluated part was immersed in water and bubbles appeared.
(5) The water stop performance is shown in Table 1. And the water stop performance pass was shown by "(circle)" and "(double-circle)", and the failure was shown by "x".

表１から明らかなように常温でも十分な止水性能が出るが、被覆を50℃まで温めると500kPa以上という非常に高い止水性能を得ることが出来るため信頼性向上につながる。

As can be seen from Table 1, sufficient water-stopping performance can be obtained even at room temperature, but if the coating is heated to 50 ° C, a very high water-stopping performance of 500 kPa or more can be obtained, leading to improved reliability.

In addition, RTV silicone (Shin-Etsu Chemical KE4895), instant adhesive (Toagosei Aron Alpha), epoxy resin bandico Araldite (2 liquids), and urethane resin bandico quinnate (2 liquids) are used as waterproofing agents (waterproofing agents). And if
Table 2 shows the waterproof performance when RTV silicone (Shin-Etsu Chemical KE3424G), hot melt (Toyobo Viroshot GM960, grease (grease for Nippon Oil Corporation), and butyl rubber (Sumitomo 3 MEMS Pat III) are used.

これらの結果から電線の被覆を５０℃以上に加温することにより防水剤が浸透し易くなり、極めて良好な止水性能を得ることができた。また、電線外径を測定することにより防水剤の浸透度合いを検出して非破壊で製品の最大耐シール圧を予測することができることが明かとなった。

From these results, it was possible to easily penetrate the waterproofing agent by heating the wire coating to 50 ° C. or higher, and an extremely good water stop performance could be obtained. It was also found that the maximum seal pressure resistance of a product can be predicted nondestructively by measuring the outer diameter of the wire to detect the degree of penetration of the waterproofing agent.

  By warming the electric wire in this manner, it is possible to help the expansion of the coating when the waterproofing agent penetrates into the electric wire, and to obtain the effect of promoting the penetration of the waterproofing agent. Moreover, the penetration | invasion degree of a waterproofing agent can be confirmed from the exterior by non-destructive by detecting the variation | change_quantity of the electric wire outer diameter by expansion | swelling of the coating | cover at this time.

  The electric wire infiltrated with the waterproofing agent may not have a connection portion with other conductors such as a connection terminal, and more effective by sucking from the end of the electric wire with a suction device and using negative pressure. Although it is obtained, sufficient penetration can be obtained only by capillary action. In addition, it is important to warm the wire coating, and not limited to the infrared heater. If there is a similar function, either a warm air heater or current heating to the wire conductor may be used. Furthermore, the outer diameter of the electric wire coating may be measured as long as a change of about 0.1 μm can be reliably detected, and does not need to be a digital dimension measuring device. Moreover, you may perform an electric wire covering outer diameter test | inspection, making a waterproofing agent penetrate | infiltrate.

  Furthermore, not only the waterproofing agent but also a conductive material for improving the connection between the electric wire and other conductors may be permeated, and the object to be permeated need not be an electric wire. That is, according to the present invention, when a material having a capillary action, for example, a liquid material such as silicone, is allowed to permeate into a flexible jacket, if the flexibility can be increased by warming the outer skin, the penetration is promoted. This shows that an effect is obtained, and it is possible to confirm how far the material has penetrated by detecting the external dimensions at this time.

It is explanatory drawing of a capillary phenomenon. It is a block diagram of the water stop processing apparatus which enforces the penetration promotion method of the waterproofing agent of the present invention. It is sectional drawing before making the waterproofing agent of the electric wire shown in FIG. 2 penetrate | infiltrate. FIG. 3 is a cross-sectional view after a waterproofing agent is infiltrated into the electric wire shown in FIG. 2.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Thin tube 2 Liquid 11 Electric wire 11a One side edge part 11b Other side edge part 12 Core wire (elementary wire)
DESCRIPTION OF SYMBOLS 13 Cover 14 Connection terminal 14a Crimp part 15 Suction device 16 Waterproof agent supply machine 17 Waterproof agent 18 Heat source 19 Digital dimension measuring device D ₁ Outside diameter before infiltrating waterproof agent of electric wire D ₂ After infiltrating waterproof agent of electric wire Outside diameter H Liquid level height r Capillary radius θ Contact angle

Claims (8)

A method of infiltrating a waterproofing agent between the core wires of an electric wire covering a plurality of core wires,
A method for promoting penetration of a waterproofing agent, wherein the surface temperature of the wire coating is heated to 50 ° C. or higher.   The method of promoting penetration of a waterproofing agent according to claim 1, wherein the waterproofing agent is infiltrated from one end of the electric wire and sucked from the other end to make the internal pressure of the electric wire less than the external atmospheric pressure.   The method for promoting penetration of a waterproofing agent according to claim 1 or 2, wherein the place where the waterproofing agent penetrates is a portion where an electric wire and another conductor are connected in advance.   A waterproofing agent penetration inspection method, wherein a waterproofing agent is infiltrated between the core wires of an electric wire covered with a plurality of core wires, and the degree of penetration of the waterproofing agent is inspected from a change in the outer diameter of the electric wire.   5. The method for inspecting a waterproofing agent according to claim 4, wherein a change in the outer diameter of the electric wire is inspected by a dimension measuring instrument.   A waterproofing agent penetration inspection method, wherein a waterproofing agent is infiltrated between the core wires of an electric wire covered with a plurality of core wires, and the penetration amount and penetration distance of the waterproofing agent are inspected from the amount of change in the outer diameter of the electric wire.   The amount of change in the outer diameter of the electric wire is characterized by inspecting the penetration distance of the waterproofing agent by measuring the outer diameter at two or more locations in the length direction of the electric wire using two or more dimension measuring instruments. Item 7. A penetration test method for a waterproofing agent according to Item 6. The waterproofing treatment is performed by infiltrating the waterproofing agent between the core wires of the electric wire by the method of promoting penetration of the waterproofing agent according to any one of the first to third aspects, and the waterproofing process is performed according to any one of the fourth to seventh aspects. A method for waterproofing an electric wire, comprising: inspecting a degree of penetration by a penetration test method for a waterproofing agent.

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