JP6549920B2 - Wire with Terminal, Wire Harness Structure, and Method of Manufacturing Wire with Terminal - Google Patents

Description

  The present invention relates to a terminal-equipped electric wire or the like used in a car or the like.

  Conventionally, the connection between the wire and the terminal in a wire harness for a car is generally crimped bonding in which the wire is crimped and crimped with a terminal called an open barrel type. However, in such a wire harness, if moisture or the like adheres to the connection portion of the wire and the terminal, oxidation of the metal surface used for the wire proceeds, and the resistance at the joint increases. In addition, when metals used for the wire and the terminal are different, corrosion between dissimilar metals proceeds. The progress of the corrosion of the metal material at the connection portion causes cracking or poor contact of the connection portion, which inevitably affects the product life. In particular, in recent years, a wire harness in which a wire is made of an aluminum alloy and a terminal is made of a copper alloy is being put to practical use, and the problem of corrosion of a joint is becoming remarkable.

  Here, for example, when water adheres to the contact portion of dissimilar metals such as aluminum and copper, so-called electrolytic corrosion may occur due to the difference in corrosion potential. In particular, since the potential difference between aluminum and copper is large, the corrosion on the side of aluminum, which is an electrical crucible, progresses. For this reason, the connection state between the lead wire and the crimp terminal becomes unstable, and there is a possibility that an increase in electrical resistance due to an increase in contact resistance or a decrease in wire diameter, or disconnection may occur to lead to malfunction or failure of electrical components.

  In such a terminal-attached electric wire with which dissimilar metals are in contact, for example, a terminal having a cylindrical crimped part sealed at one end is used, and after the end of the electric wire is inserted into the cylindrical crimped part, the cylindrical crimped A method has been proposed in which a part is crimped by crimping (Patent Document 1).

JP, 2014-164913, A

  As described in Patent Document 1, when a coated lead is inserted into a terminal in which the end of a crimped portion is sealed and crimped, water infiltrates into the inside of the terminal as the coated portion and the crimped portion adhere closely. It can be prevented.

  However, in the coated pressure-bonded portion, the inner conductor is also compressed, but if the outer periphery of the inner conductor has a large uneven shape, the thickness of the coated portion may become uneven after pressure bonding. For this reason, in order to ensure higher water repellency, it is desirable to minimize the change in the thickness of the coating portion.

  This invention is made in view of such a problem, and an object of this invention is to provide the electric wire with a terminal etc. which can ensure high waterproofness.

In order to achieve the above-described object, a first invention is a terminal-equipped electric wire in which a coated wire and a terminal are connected, and the terminal has a crimping portion to which the coated wire is crimped, and a terminal body The pressure-bonding portion is a tubular shape closed at one end, and has a coating pressure-bonding portion for pressure-bonding a covering portion, and a conductor pressure-bonding portion for crimping a conductive wire exposed from the covering portion. In a cross section perpendicular to the longitudinal direction of the coated conducting wire, strands are twisted and formed, assuming a circumscribed circle of the conducting wire, the circumscribed circle and the covering portion protruding in the central direction from the circumscribed circle Assuming that the distance between the tip with the largest distance from the tip is a valley depth, and the distance between the circumscribed circle at the valley depth and the outer peripheral surface of the covering is a covering thickness, the pressure before crimping der valley depth / the covering part thickness is 55% or less The conductive wire is compressed and deformed into a substantially circular shape in advance before being covered with the covering portion, and the outer diameter of the circumscribed circle is 1.7 mm to 2.1 mm, and the compression ratio of the covering crimping portion Is 50% to 80% .

  It is desirable that the valley depth / the coating thickness be 45% or less.

  According to the first invention, in a cross section perpendicular to the longitudinal direction of the coated lead, assuming a circumscribed circle of the lead, a valley at a distance from the tip of the sheathed portion protruding from the circumscribed circle to the center of the sheathed portion with respect to the sheath thickness. By setting the ratio of the part depth to 55% or less, it is possible to reduce the change in the thickness of the coated part even after the coated part is crimped. For this reason, the variation in the amount of compression due to the portion of the covering portion can be reduced. As a result, the adhesion between the coated portion and the coated pressure-bonded portion becomes substantially uniform over the entire circumference, and water fastness can be enhanced.

  The effect on such a water barrier property is particularly great when the aforementioned ratio is 45% or less.

  Moreover, the ratio mentioned above can be made small by compressively deforming the conducting wire into a substantially circular shape in advance before covering with a covering part.

  Further, the present invention is particularly effective for a relatively thick coated wire in which the outer diameter of the circumscribed circle is 1.7 mm to 2.1 mm.

  A second invention is a wire harness structure characterized in that a plurality of terminal-attached electric wires according to the first invention are bundled.

  In the present invention, a plurality of terminal-attached electric wires can be bundled and used.

3rd invention is a manufacturing method of the electric wire with a terminal with which a coated lead and a terminal were connected, and the above-mentioned terminal has a crimp part by which the above-mentioned coated lead is crimped, and a terminal main part, A cylindrical shape closed at one end has a coated crimping portion for crimping the coated portion, and a conductive crimped portion for crimping the conductive wire exposed from the coated portion, and the conductive wire twists a plurality of strands When the circumscribed circle of the conducting wire is assumed in the cross section perpendicular to the longitudinal direction of the coated conducting wire by fitting and compressing in a substantially circular shape, the circumscribed circle and the circumscribing circle are used. The distance of the portion with the largest distance from the tip of the covering portion protruding in the central direction is the valley depth, and the distance between the circumscribed circle at the portion of the valley depth and the outer peripheral surface of the covering portion is the covering portion When the thickness, before compression, the valley depth / the covering portion Was 55% or less of the conductor, before being coated with the coating portion, is previously compressed and deformed in a substantially circular shape, the outer diameter of the circumscribed circle is a 1.7Mm～2.1Mm, wherein In the method of manufacturing a terminal-attached electric wire, the coated conductive wire is crimped at the coated crimping portion such that the compression ratio of the coated crimping portion is 50% to 80% .

  According to the third invention, it is possible to manufacture a terminal-attached electric wire which is excellent in water blocking property in the coated pressure-bonded portion.

  ADVANTAGE OF THE INVENTION According to this invention, the electric wire with a terminal etc. which can ensure high waterproofness can be provided.

The perspective view of electric wire 10 with a terminal. Sectional drawing of the electric wire 10 with a terminal. (A), (b) is sectional drawing of the coated conducting wire 23. FIG. The disassembled perspective view of the electric wire 10 with a terminal. It is sectional drawing which shows the state which has arrange | positioned the crimping | compression-bonding part 5 between metal mold | die 31a, 31b, (a) is a figure which shows before crimping, (b) is a figure which shows the state crimped | bonded. Schematic which shows a test apparatus.

  FIG. 1 is a perspective view showing a terminal equipped electric wire 10 according to the present invention, and FIG. 2 is an axial sectional view of the terminal equipped electric wire 10. The terminal-attached electric wire 10 is configured by crimping the terminal 1 and the coated conductive wire 23.

  The coated lead 23 is configured by coating the lead 25 with an insulating coating 27. The conducting wire 25 is made of, for example, an aluminum-based material. When the coated lead 23 is inserted into the crimped portion 5 of the terminal 1, the coated portion 27 of a part of the tip of the coated lead 23 is peeled off to expose the lead 25. In addition, as the coating | coated part 27, what is normally used in the field | area of this technique, such as a polyvinyl chloride (PVC) and polyethylene, can be selected.

  The terminal 1 is made of copper and comprises a terminal body 3 and a crimp portion 5. The terminal main body 3 is formed by forming a plate-like material having a predetermined shape into a cylindrical body having a rectangular cross section. The terminal body 3 has an elastic contact piece 15 formed at the front end portion 17 by folding a plate-like material into a rectangular cylinder. The terminal body 3 is connected by inserting a male terminal and the like from the front end portion 17.

  The crimped portion 5 is formed by rounding the plate-like material so as to form a cylindrical body having a circular cross section, butting the side edges of the plate-like material together and joining them together at the joining portion 21 for integration. In addition, a sealing portion 11 is provided at the front end portion (terminal body 3 side) of the crimped portion 5. That is, the crimping part 5 has a substantially cylindrical shape with one end closed, and is sealed except for the rear end part 19 where the coated conducting wire is inserted. The joint portion 21 and the sealing portion 11 are welded by, for example, laser welding or the like. The coated conductive wire 23 is inserted and crimped from the rear end 19 of the crimped portion 5 formed in a tubular shape.

  The crimping portion 5 includes a coated crimping portion 9 for crimping the coated portion 27 of the coated lead 23, and a conductor crimping portion 7 for crimping a portion where the coated portion 27 is removed and the lead 25 is exposed at the tip of the coated lead 23. It consists of

  FIG. 3A is a cross-sectional view taken along line A-A of FIG. 2 and is a cross-sectional view perpendicular to the longitudinal direction of the coated conductive wire 23. The conducting wire 25 is formed by twisting a plurality of strands. In the illustrated example, seven strands are substantially closely arranged. The number and arrangement of the strands are not limited to the illustrated example.

  As described above, the conductive wire 25 formed by twisting a plurality of strands has an uneven shape on the outer peripheral portion. Here, the circumscribed circle 29 of the conducting wire 25 is assumed so as to include all the strands (shown by dotted lines in the figure). The tip of the covering portion 27 protruding from the circumscribed circle 29 in the central direction with the circumscribed circle 29 as a reference is a valley 30 (indicated by a black circle in the drawing). When the strands are in contact with each other, the valley portion 30 substantially matches the contact portion between the strands. On the other hand, even when the strands are slightly separated from each other, the tip of the covering portion 27 (the point closest to the center of the circumscribed circle 29 with respect to the periphery) is used as the valley portion.

  Here, in the example shown in the figure, since the valleys 30 are formed between the respective strands, six valleys are formed. Therefore, the distance between the circumscribed circle 29 and the valley 30 is obtained on the center line of the circumscribed circle 29 passing through the respective valleys 30. In the present invention, the depth (B in the figure) between the circumscribed circle 29 of the portion where the depth of the valley portion 30 is the deepest (the portion farthest from the circumscribed circle 29) is taken as the valley depth. .

  Further, on the center line of the circumscribed circle 29 indicating the valley depth, the distance (C in the figure) between the circumscribed circle and the outer peripheral surface of the covering portion 27 is taken as the covering portion thickness. When the center of the circumscribed circle 29 coincides with the center of the covering portion 27, the thickness of the covering portion 27 is substantially constant at any portion.

  Here, in the present invention, the valley depth / cover thickness (= B / C) is preferably 55% or less, and more preferably 45% or less. That is, it is desirable that the valley depth be smaller than the covering thickness. At a portion where the valley depth is large, when the covering portion 27 is crimped, the compression rate of the covering portion 27 becomes smaller than that at the other portions. For this reason, when the valley depth is increased, the adhesion between the coated portion 27 and the coated pressure-bonded portion 9 is weakened, which may deteriorate the water resistance. In particular, as the coating thickness decreases, the influence of the valley depth increases. Therefore, it can suppress that waterproofness worsens by making valley part depth / coating | coated part thickness into said range.

  As a method of reducing the valley depth in this manner, for example, by increasing the number of strands using thinner strands, the outer diameter of the conducting wire 25 can be made closer to a circle. In the present invention, the outer diameter of the strands is preferably 0.1 to 0.5 mm. If it is thinner than this, the handleability is bad and there is a risk of disconnection or the like. Also, if the thickness is larger than this, the valley depth is increased, which is not desirable.

  Moreover, before covering with the covering part 27, the lead wire 25 may be compressed in advance to approximate to a substantially circular shape. FIG. 3 (b) shows a state in which the individual strands of wire are twisted, compressed into a substantially circular shape, and then covered with a covering portion 27. Also in this case, the valley depth (B) and the covering thickness (C) can be specified as in the example shown in FIG. 3 (a). By compressing the conducting wire 25, the wire is deformed and the valley portion 30 is crushed. Therefore, the use of the compressed conducting wire can reduce the valley depth (B).

  Here, the present invention is particularly effective particularly for 2.0sq (coated wire having an outer diameter of 1.7 mm of the conductive wire 25) to 2.5 sq (coated wire having an outer diameter of 2.1 mm of the conductive wire 25). is there. Since the thickness of the coating | coated part 27 becomes thick, as for the coated conducting wire larger diameter than this, ratio of the valley part depth / coating | coated part thickness mentioned above tends to become small. On the other hand, in the case of a coated wire thinner than this (for example, 0.5sq to 0.75sq), the thickness of the coated portion 27 is originally thin, and a compressed wire may be used from the viewpoint of core misalignment prevention. In some cases, it is possible to secure sufficient waterproofness for the attached electric wire.

  On the other hand, in the case of the 2.0sq to 2.5sq. Wire, since the coating thickness is relatively thick compared to the coated wire thinner than this, the influence of the misalignment described above is less likely to occur, and a compressed wire is also conventionally used. It was not. That is, the conventional compressed conducting wire is used to prevent misalignment of the conducting wire with respect to the small-diameter coated wire, and as in the present invention, it is performed to ensure the water barrier property. It was not.

  As described above, in 2.0sq to 2.5sq where no problem of misalignment occurs, conventionally, the compression stroke for obtaining the compressed lead wire has not been performed. Therefore, the valley depth / cover thickness becomes large. On the other hand, in the present invention, with respect to a coated electric wire of the above size applied to a one-end-sealed terminal, the water barrier property is improved by setting the valley depth / cover thickness to a predetermined value or less. Found out.

  Next, the process of manufacturing the terminal-attached wire will be described. FIG. 4 is an exploded perspective view showing a state before inserting the coated conductive wire 23 into the terminal 1. First, as shown in FIG. 4, the covering portion 27 having a predetermined length at the tip of the coated conducting wire 23 is removed to expose the conducting wire 25. Next, the coated conducting wire 23 is inserted into the cylindrical crimping portion 5. Under the present circumstances, the exposed part of the conducting wire 25 is located in the inside of the conductor crimp part 7, and the coating | coated part 27 is located in the inside of the covering crimp part 9. As shown in FIG.

  As described above, the crimped portion 5 is rounded into a substantially cylindrical shape, and the edge portions are joined at the joining portion 21. In addition, a sealing portion 11 is provided at the front end portion (terminal body 3 side) of the crimped portion 5. That is, the crimped portion 5 is sealed except for the rear end portion 19 where the coated conductive wire 23 is inserted.

  FIG. 5 (a) is a cross-sectional view showing the molds 31a, 31b and the like before pressure bonding, and FIG. 5 (b) is a cross-sectional view showing the pressure-bonding section 5 during pressure bonding. The mold 31 a has a longitudinally extending semi-cylindrical cavity, a large diameter portion 34 corresponding to the coated crimping portion 9 and having a radius slightly smaller than the radius of the coated crimping portion 9; And a small diameter portion 32 having a radius smaller than that of the large diameter portion 34. The mold 31 b has a semi-cylindrical cavity extending in the longitudinal direction, and the radius of the portion corresponding to the conductor crimping portion 7 and the covering crimp portion 9 is the same as that of the mold 31 a. The large diameter portion 34 is a portion to which the coated crimping portion 9 is crimped, and the small diameter portion 32 is a portion to which the conductor crimping portion 7 is crimped.

  As shown in FIG. 5B, when the molds 31a and 31b are engaged and the crimping part 5 is compressed, the crimping part 5 is crimped to the conducting wire 25 and the covering part 27. The electric wire 10 with a terminal is manufactured by the above. In addition, it is not necessary to form uneven | corrugated shape etc. in the inner surface of metal mold | die 31a, 31b. As described above, the present invention is to improve the water resistance by making the thickness of the covering portion 27 uniform in the circumferential direction, so the inner surface of the covering pressure-bonding portion 9 may be smooth.

  Here, assuming that the total cross-sectional area of the coated conductive wire 23 in the coated portion 27 before crimping is A0 and the total cross-sectional area of the inside of the coated crimping portion 9 after crimping is A1, A1 / A0 is a compression ratio. In the present invention, the compression ratio is preferably 45 to 90%, more preferably 50% to 80%.

  As described above, by setting the valley portion depth / cover portion thickness to a predetermined value or less as in the present embodiment, the cover portion 27 is compressed substantially uniformly over the entire circumference in the cover crimping portion 9. It is possible to secure the water blocking ability.

  Next, since the terminal-equipped electric wire and the terminal-equipped electric wire as a comparison according to the present invention were produced on a trial basis and performance tests were conducted on each sample, the following description will be made.

  Air was sent from the coated wire of the terminal-attached wire toward the terminal, and it was tested whether air leaked from the rear end. FIG. 6 shows an outline of the experimental method. In the experiment, the terminal 1 crimped to the terminal-attached electric wire 10 was placed in a water tank 41 filled with water, and pressurized air was sent from the end of the terminal-attached electric wire 10 toward the terminal 1 by the regulator 42.

(Wire with terminal)
The diameter of the wire is 2.1 mm, the outer diameter of the wire is 2.8 mm, and the length of the wire is 30 cm. And the end part of the electric wire which the core wire exposed was inserted in the crimp part of this crimp terminal, and the crimp part was crimped using the crimp apparatus provided with the crimp type | mold shown in FIG. The compression ratio (the ratio of the cross-sectional area after compression to the cross-sectional area before compression) of the electric wire at the coated crimped portion at this time was 70%.

  In Examples 1 and 2 and Comparative Example 1, the valley depth / cover thickness are different. In addition, the valley part depth and coating | coated part thickness cut | disconnected the coated conducting wire, grind | polished the cut surface, and measured it using Keyence Corporation make VR3000.

For each of the terminal-attached wires, a sample left for 120 hours at 80 ° C. and a sample left for 400 hours at 80 ° C. were prepared, and the presence or absence of air leak was confirmed. The air pressure was 30 kPa, and n = 10 was evaluated for each. At this time, no air leak was confirmed in any case.
In addition, in order to confirm the waterproof property in a more severe environment, each electric wire with a terminal is left in a 120 ° C. environment for 120 hours, then left for 240 hours, then left for 400 hours, then left for 500 hours, then left for 600 hours. In each of the latter, the presence or absence of air leak was confirmed. The air pressure was 30 kPa, and n = 10 was evaluated for each. The results are shown in Table 1.

  In Table 1, 〇 indicates that there was no air leak, Δ indicates that an air leak was confirmed in part, and x indicates that an all-round air leak was confirmed. As shown in Table 1, in Example 1 in which the valley depth / cover thickness was 45%, no air leak was observed at all times. In addition, in Example 2 in which the valley depth / cover thickness was 55%, air leakage was observed in part after leaving for 500 hours, but generally good results could be obtained.

  On the other hand, in Comparative Example 1, since the valley depth / cover thickness exceeds 55%, an air leak is already seen in part after leaving for 120 hours, and after leaving for 600 hours, all in the air leak. confirmed.

  In addition, this result showed the same tendency, even if it changes a compression rate in 50 to 80% of range. Moreover, the same result was obtained even when the diameter of the conducting wire was 1.7 mm.

  Although the embodiments of the present invention have been described above with reference to the attached drawings, the technical scope of the present invention is not influenced by the above-described embodiments. It is apparent that those skilled in the art can conceive of various changes or modifications within the scope of the technical idea described in the claims, and they are naturally also within the technical scope of the present invention. It is understood that it belongs.

  For example, although the Example described the case where aluminum was used for the wire, it is not limited to this, You may use copper for a wire.

  In addition, a plurality of terminal-attached electric wires according to the present invention can be bundled and used. In the present invention, a structure in which a plurality of terminal-attached electric wires are bundled in this manner is referred to as a wire harness structure.

DESCRIPTION OF SYMBOLS 1 ...... Terminal 3 ...... Terminal main body 5 ...... Crimping part 7 ...... Coating crimping part 9 ...... Conductor crimping part 10 ...... Wire with terminal 11 ...... Sealing part 15 ...... Elasticity Contact pieces 17 ...... front end 19 ...... rear end 21 ...... joint 23 ...... coated lead 25 ...... lead 27 ...... cover 29 ...... circumscribed circle 30 ...... valley 31a, 31b ...... Mold 32 ...... Small diameter portion 34 ...... Large diameter portion 41 ...... Water tank 43 ...... Regulator

Claims (4)

A terminal-equipped wire in which a coated wire and a terminal are connected,
The terminal includes a crimping portion to which the coated conductive wire is crimped, and a terminal body.
The crimped portion has a cylindrical shape closed at one end, and includes a coated crimped portion that crimps the coated portion, and a conductive crimped portion that crimps a conductive wire exposed from the coated portion.
The conductive wire is formed by twisting a plurality of strands,
In a cross section perpendicular to the longitudinal direction of the coated conducting wire, when the circumscribing circle of the conducting wire is assumed, the distance between the circumscribing circle and the tip of the covering portion protruding from the circumscribing circle in the center direction is the largest Assuming that the distance is a valley depth, and the distance between the circumscribed circle at the valley depth and the outer peripheral surface of the covering is a covering thickness , the valley depth / the covering thickness before crimping. Saga Ri der 55% or less,
The lead wire is compressed and deformed into a substantially circular shape in advance before being covered with the covering portion,
The outer diameter of the circumscribed circle is 1.7 mm to 2.1 mm,
Wire with terminals which compressibility of the insulation crimp portion is characterized in 50-80% der Rukoto.   The electric wire with a terminal according to claim 1, wherein the valley depth / the coating thickness is 45% or less. A wire harness structure in which a plurality of the terminal-equipped electric wires according to claim 1 or 2 are bundled. A method of manufacturing a terminal-attached electric wire in which a coated lead and a terminal are connected,
The terminal includes a crimping portion to which the coated conductive wire is crimped, and a terminal body.
The crimped portion has a cylindrical shape closed at one end, and includes a coated crimped portion that crimps the coated portion, and a conductive crimped portion that crimps a conductive wire exposed from the coated portion.
In the case where the circumscribed circle of the conducting wire is assumed in a cross section perpendicular to the longitudinal direction of the coated conducting wire, by twisting a plurality of strands of wire and compressing the wire into a substantially circular shape and then covering with the covering portion. The distance between the circumscribed circle and the portion of the portion where the distance between the circumscribed circle and the tip of the covered portion protruding in the central direction is the largest is the valley depth, and the circumscribed circle and the sheath at the valley depth Assuming that the distance to the outer peripheral surface of the portion is the thickness of the covering portion , the depth of the valley portion / the thickness of the covering portion is 55% or less before the crimping .
The lead wire is compressed and deformed into a substantially circular shape in advance before being covered with the covering portion,
The outer diameter of the circumscribed circle is 1.7 mm to 2.1 mm,
A method of manufacturing an electric wire with a terminal, characterized in that the coated conductive wire is crimped at the coated crimping portion such that the compression ratio of the coated crimping portion is 50% to 80% .

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