JP7645662B2 - Manufacturing method of electric wire with terminal, manufacturing method of wire harness - Google Patents

Description

The present invention relates to a method for manufacturing an electric wire with a terminal, for example, for use in automobiles, etc.

Typically, automotive wire harnesses are made by connecting crimp terminals to the conductors of covered conductors, bundling them together, and wiring them as signal lines for automobiles, etc. In general, covered conductors and crimp terminals are connected by removing the covering from the tip of the covered conductor and crimping the exposed conductor to the conductor crimping part.

When the electric wires used become thinner, it becomes difficult to maintain strength using only the conductor that constitutes the wire, so electric wires containing reinforcing members are being considered. For example, when using an electric wire made of a conductor with a tensile strength of about 30 N, in order to ensure a tensile strength exceeding 80 N required for electric wires for automobiles, electric wires containing reinforcing members have been proposed in which the conductor is wound in a spiral shape around the outer circumference of a metallic or nonmetallic reinforcing member.

As an example of such an electric wire containing a tension member, a high-tension electric wire has been proposed in which multiple soft copper wires are arranged around a carbon fiber as a tension member (Patent Document 1).

JP 2002-150841 A

Figure 10 shows the process of crimping such a tensile strength electric wire to a terminal. The coated conductor wire 111 has a structure in which a conductor wire 113 is covered with a coating portion 115. The terminal 101 to be crimped has a terminal body 103 and a conductor crimping portion 107 to which the conductor wire 113 is crimped.

To crimp the terminal 101 and the coated conductor 111, first, as shown in FIG. 10(a), the coating 115 is removed from the end of the coated conductor 111 to expose the internal conductor 113. FIG. 11(a) is a cross-sectional view of line A-A in FIG. 10(a). The conductor 113 is composed of multiple strands 113a twisted together around the outer periphery of a tensile member 114.

Next, as shown in FIG. 10(b), the exposed conductor 113 is inserted into the conductor crimping portion 107. FIG. 11(b) is a cross-sectional view of line B-B in FIG. 10(b). The conductor crimping portion 107 is, for example, tubular, and has an inner diameter larger than the diameter of the conductor 113.

Next, as shown in FIG. 10(c), the conductor crimping portion 107 is crimped to crimp the conductor 113. FIG. 11(c) is a cross-sectional view taken along line C-C in FIG. 10(c). By crimping the conductor crimping portion 107, the wire 113a is crushed and comes into close contact with the inner surface of the conductor crimping portion 107. This establishes electrical continuity between the wire 113a and the conductor crimping portion 107.

Here, the tensile strength body 114 is less deformed during crimping than the wire 113a. That is, when the conductor crimping portion 107 is compressed, the wire 113a is crushed and deformed preferentially compared to the tensile strength body 114. At this time, the wire 113a is deformed, the cross-sectional area of the wire 113a decreases, and the wire 113a stretches in the axial direction. On the other hand, the tensile strength body 114 hardly stretches, so the distance between the terminal 101 and the covering portion 115 hardly changes, and only the wire 113a stretches in the axial direction. As a result, the wire 113a expands in the radial direction at the rear end of the terminal 101, as shown in FIG. 10(c).

If the wire 113a spreads in the radial direction in this way, there is a risk of it breaking due to contact with the edge of the end of the terminal 101 or other components. On the other hand, if the wire does not have a tension member 114, the conductor 113 stretches in the longitudinal direction in a substantially uniform manner, so this spreading can be suppressed. However, as mentioned above, in particular with a thin-diameter coated conductor, it may not be possible to eliminate the tension member in order to ensure tensile strength. For this reason, a method is desired to suppress the spreading of the wire 113a during crimping, even for coated conductors that use tension members.

The present invention was made in consideration of these problems, and aims to provide a method for manufacturing an electric wire with a terminal that can suppress the spread of the wire when crimped.

In order to achieve the above-mentioned object, a first invention is a method for manufacturing an electric wire with a terminal in which a covered conductor wire and a terminal are electrically connected, the covered conductor wire has a tension member, a conductor wire, and a coating portion that coats the tension member and the conductor wire, the terminal has a conductor crimping portion to which the conductor wire exposed from the coating portion at a tip of the covered conductor wire is crimped, and when the conductor crimping portion and the conductor wire are crimped, a part of the conductor crimping portion on the coating portion side is crimped relative to a longitudinal direction of the covered conductor wire, and a part of the conductor crimping portion on the tip side of the conductor wire is crimped relative to a longitudinal direction of the covered conductor wire. the amount of compression of the portion of the conductor crimping portion on the coating side during crimping is made greater than the amount of compression of the portion of the conductor crimping portion on the tip side of the conductor, causing the conductor to deform more than the tensile body and extend the conductor toward the tip side of the conductor crimping portion; and by first crimping a portion of the rear end side of the conductor crimping portion, which is part of the conductor crimping portion on the coating side, elongation of the conductor further toward the rear end side is suppressed .

The die for crimping the conductor crimping portion may be formed so that the portion for crimping the portion of the conductor crimping portion on the coating portion side protrudes in the compression direction compared to the portion for crimping the portion of the conductor crimping portion on the tip side of the conductor.

The die for crimping the conductor crimping portion may have multiple concave and convex shapes in the longitudinal direction of the conductor crimping portion.

The die for crimping the conductor crimping portion may be divided into at least two parts, and the die for crimping the part of the conductor crimping portion on the coating side may be operated first to crimp, and the die for crimping the part of the conductor crimping portion on the tip side of the conductor may be operated later to crimp.

In the conductor crimping portion before crimping, the thickness of the conductor crimping portion on the side of the covering portion may be thicker than the thickness of the conductor crimping portion on the tip side of the conductor.

According to the first invention, the coated conductor has a conductor and a tension member, and the tension member ensures the tensile strength of the conductor. In addition, when crimping the conductor crimping portion, crimping of the part of the conductor crimping portion on the coating side is started before crimping of the part of the conductor crimping portion on the tip side of the conductor, thereby restricting the stretching of the conductor toward the coating during crimping. This makes it possible to suppress the spread of the conductor between the conductor crimping portion and the coating, which occurs when the conductor stretches toward the coating during crimping.

At this time, the die for crimping the conductor crimping portion is formed so that the portion for crimping the conductor crimping portion on the coating side protrudes in the compression direction compared to the portion for crimping the conductor crimping portion on the tip side of the conductor, allowing the conductor crimping portion to be crimped by the same die operation as in the past.

In addition, by providing the die for crimping the conductor crimping portion with multiple projections and recesses in the longitudinal direction of the conductor crimping portion, the projections on the die begin crimping first, and the extension of the conductor is restricted at these projections before the recesses on the die begin crimping. This makes it possible to suppress the spread of the conductor between the conductor crimping portion and the coating, which occurs when the conductor stretches toward the coating during crimping.

Also, the same effect can be obtained by dividing the die for crimping the conductor crimping portion into at least two parts, first operating the die for crimping the part of the conductor crimping portion on the coating side, and then operating the die for crimping the part of the conductor crimping portion on the tip side of the conductor. In this case, the substantially entire conductor crimping portion after crimping can be crimped with substantially the same compression ratio as in the conventional case.

In addition, by making the thickness of the conductor crimping portion on the coating side thicker than the thickness of the conductor crimping portion on the tip side of the conductor before crimping, it is possible to start crimping the part of the conductor crimping portion on the coating side first, even when crimping is performed using a conventional die. This makes it possible to suppress the spread of the conductor between the conductor crimping portion and the coating, which occurs when the conductor stretches toward the coating during crimping.

The amount of compression of a portion of the rear end of the conductor crimping portion may be greater than other portions and may be greater than the amount of compression of a tip side of the conductor crimping portion and a central portion of the conductor crimping portion.

The thickness of the conductor crimping portion on the coating side may be greater than the thickness of the conductor crimping portion on the tip side of the conductor.

By making the amount of compression of the portion of the conductor crimping portion on the coating side greater than the amount of compression of the portion of the conductor crimping portion on the tip side of the conductor, it is possible to prevent the conductor in the conductor crimping portion on the tip side of the conductor from stretching toward the coating side.

In addition, by making the thickness of the conductor crimping portion on the coating side thicker than the thickness of the conductor crimping portion on the tip side of the conductor, the height of the conductor crimping portion on the outer surface can be made approximately constant.

A second aspect of the present invention is a method for producing a wire harness, comprising integrating a plurality of electric wires with terminals produced by the method for producing an electric wire with terminal according to the first aspect of the present invention.

According to the second aspect of the present invention, for example, a wire harness in which a plurality of thin electric wires are bundled can be obtained.

The present invention provides a method for manufacturing an electric wire with a terminal that can suppress the spread of the wire during crimping.

FIG. 1A is a cross-sectional view showing an electric wire with a terminal 10, and FIG. 1B is a cross-sectional view taken along line XX of FIG. FIG. 2 is a diagram showing the terminal 1 and the coated conductor wire 11 before crimping. 4A and 4B are diagrams showing a crimping process of the conductor crimping portion 7 of the electric wire with terminal 10. 6A and 6B are diagrams showing other shapes of the mold 21b. 13A and 13B are diagrams showing another crimping process of the conductor crimping portion 7 of the electric wire with terminal 10. 13A and 13B are views showing another crimping process of the conductor crimping portion 7 of the electric wire with terminal 10, and 13C is an enlarged view of the Y portion of 13B. 13A and 13B are diagrams showing another crimping process of the conductor crimping portion 7 of the electric wire with terminal 10. FIG. 4A to 4C are diagrams showing a crimping process of a conventional conductor crimping section 107. 10(a) is a cross-sectional view taken along line AA in FIG. 10(a), (b) is a cross-sectional view taken along line BB in FIG. 10(b), and (c) is a cross-sectional view taken along line CC in FIG. 10(c).

First Embodiment
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a perspective view showing an electric wire with terminal 10, Fig. 2(a) is a cross-sectional view of the electric wire with terminal 10, and Fig. 2(b) is a cross-sectional view of a covered conductor wire 11, taken along line X-X in Fig. 2(a). The electric wire with terminal 10 is configured by electrically connecting a terminal 1 and a covered conductor wire 11.

As shown in FIG. 2(b), the coated conductor 11 has a tension member 14, a conductor 13, and a coating 15 that coats the tension member 14 and the conductor 13. The conductor 13 is made up of multiple strands 13a. The number of strands in the conductor 13 is not particularly limited.

The tension member 14 is a member that receives tension in response to a tensile load. In the illustrated example, for example, in a cross section perpendicular to the longitudinal direction of the coated conductor 11, at least one tension member 14 is located approximately at the center of the coated conductor 11, and multiple strands 13a are arranged on the outer periphery of the tension member 14. Furthermore, the strands 13a may be twisted in a spiral shape in the longitudinal direction of the coated conductor 11 on the outer periphery of the tension member 14.

The arrangement of the strength members 14 is not limited to the example shown in FIG. 2(b). For example, the conductor 13 (strand 13a) and multiple strength members 14 may be arranged so as to be twisted together. Also, multiple conductors 13 each having a strength member 14 covered with a conductor may be twisted together. Also, the conductor may be arranged so as to cover the outer periphery of the central strength member 14. In other words, in the case of a covered conductor 11 containing a strength member, there is no particular limitation on its cross-sectional shape as long as it has at least one conductor and at least one strength member.

The tension member 14 may be a metal wire such as a steel wire, or may be made of resin or fiber-reinforced resin. The tension member 14 may also be made of a bundle of multiple fibers such as aramid fibers.

The conductor 13 is made of, for example, copper, a copper alloy, aluminum, or an aluminum alloy, and a covering 15 that covers the conductor 13. The conductor 13 is more deformed during crimping than the tensile body 14. In particular, when the tensile body 14 is made of a nonmetallic material, the tensile body 14 hardly deforms at all compared to the conductor 13. In other words, the tensile body 14 is made of a material that is relatively hard (e.g., has a high Young's modulus) compared to the conductor 13.

Here, this embodiment is effective when the cross-sectional area of the conductor 13 (total cross-sectional area of the wires 13a) is 0.3 sq. or less. Also, for example, since the conductor 13 is used together with the tensile body 14, the cross-sectional area of the conductor 13 may be 0.05 sq. or less. By using the tensile body 14, for example, even if the cross-sectional area of the conductor 13 is 0.05 sq. or less, the tensile strength of the conductor at the conductor crimping portion 7 can be ensured to be 50 N or more.

The terminal 1 is formed by connecting a terminal body 3 and a crimping portion 5. The terminal 1 is made of, for example, copper, a copper alloy, aluminum, or an aluminum alloy. The terminal body 3 is a round terminal provided with a bolt fastening portion. The terminal body 3 may be a female terminal into which a male terminal or the like is inserted from the front end, or may be an insertion tab of a male terminal.

The crimping portion 5 has a conductor crimping portion 7 that crimps the conductor 13 exposed from the coating portion 15 at the tip side of the coated conductor wire 11, and a coating crimping portion 9 that crimps the coating portion 15 of the coated conductor wire 11. In this embodiment, the conductor crimping portion 7 is tubular (approximately cylindrical) that is closed in the circumferential direction, and the coating crimping portion 9 is an open barrel type. Note that the coating crimping portion 9 is not necessarily required.

In addition, serrations (not shown) may be provided in the circumferential direction (perpendicular to the longitudinal direction) on a portion of the inner surface of the conductor crimping portion 7. By forming serrations in this manner, the oxide film on the surface of the conductor 13 is easily destroyed when the conductor 13 is crimped, and the contact area with the conductor 13 can be increased.

In this embodiment, the compression amount of the part of the conductor crimping portion 7 on the coating portion 15 side is larger than the compression amount of the part of the conductor crimping portion 7 on the tip side of the conductor 13. In other words, the compression rate of the part of the conductor crimping portion 7 on the coating portion 15 side is smaller than the compression rate of the part of the conductor crimping portion 7 on the tip side of the conductor 13. The compression rate of the conductor crimping portion 7 is the cross-sectional area of the conductor 13 after compression/the cross-sectional area of the conductor 13 before compression at that part. For this reason, the height of the conductor crimping portion 7 is not constant, but a gradient is formed in which the height gradually increases from the coating crimping portion 9 side toward the terminal body 3 side.

Next, a method for manufacturing the electric wire with terminal 10 will be described. FIG. 3 is a perspective view showing the terminal 1 and the covered conductor wire 11 before crimping. As described above, the terminal 1 has a terminal body 3 and a tubular portion 7a. The tubular portion 7a is tubular and closed in the circumferential direction. The tubular portion 7a may be formed, for example, by rolling a plate member, butting the ends together, and joining them by welding in the longitudinal direction, or the terminal 1 may be formed by expanding the tubular member. The tubular portion 7a corresponds to the conductor crimping portion 7.

First, as described above, the coating 15 at the tip of the coated conductor 11 is stripped off to expose the conductor 13 at the tip. Next, the conductor 13 is inserted into the tubular portion 7a. At this time, the tip of the conductor 13 may protrude from the tip of the tubular portion 7a.

In addition, a terminal processing section may be formed at the tip of the conductor 13 before inserting the conductor 13 into the tubular section 7a. The terminal processing section is a processing section that integrates the individual strands of the conductor 13 so that they do not come apart. The terminal processing section can be formed, for example, by compressing at least the tip of the conductor 13 from the outer periphery. In this way, by compressing the tip of the conductor 13 from the outer periphery, the strands 13a are prevented from coming apart, making it easier to insert the conductor 13 into the tubular section 7a.

As an end processing section, the wires 13a may be plated together or separately at least at the tip of the conductor 13. In this way, plating is applied from the outer periphery to the tip of the conductor 13, which prevents the wires 13a from coming apart and makes it easier to insert the wires into the tubular section 7a. The end processing section is not limited to methods using compression or plating, and for example, the tip of the conductor 13 may be soldered or welded to prevent the wires 13a from coming apart. Multiple end processing methods, such as compression from the outer periphery and batch plating, may be used in combination.

Next, the terminal 1 with the coated conductor wire 11 placed in the crimping portion 5 is set in a mold. FIG. 4(a) is a cross-sectional view showing molds 21a and 21b for manufacturing the terminal-attached electric wire 10 before crimping. The molds 21a and 21b have, for example, a substantially semi-cylindrical cavity extending in the longitudinal direction, and the conductor crimping blade die 23 corresponding to the conductor crimping portion 7 and the coating crimping blade die 25 corresponding to the coating crimping portion 9 have shapes corresponding to the shape of the tubular portion 7a of the conductor crimping portion 7 and the open barrel shape of the coating crimping portion 9, respectively.

Here, in a cross section parallel to the axial direction of the crimping portion 5, the crimping surface of the conductor crimping blade die 23 is not perpendicular to the compression direction, but is formed so that the inner diameter gradually decreases from the side of the coating crimping blade die 25 (the right side in the figure, hereinafter simply referred to as the rear end side) to the opposite side of the coating crimping blade die 25 (the left side in the figure, hereinafter simply referred to as the tip side). In other words, the die 21b (conductor crimping blade die 23) that crimps the conductor crimping portion 7 is formed so that the portion that crimps a part of the conductor crimping portion 7 on the rear end side (the coating portion 15 side) protrudes toward the opposing die 21a compared to the portion that crimps a part of the conductor crimping portion 7 on the tip side (the tip side of the conductor 13).

Figure 4(b) shows the state immediately after the upper die 21b is lowered to start crimping. When the die 21b shown in the figure is used to crimp the conductor crimping portion 7 and the conductor 13, crimping of a part of the conductor crimping portion 7 on the coating portion 15 side (a part on the rear end side of the conductor crimping portion 7) can be started before crimping of a part of the conductor crimping portion 7 on the tip side of the conductor 13 (a part on the tip side of the conductor crimping portion 7) in the longitudinal direction of the coated conductor 11. In other words, when crimping of a part of the conductor crimping portion 7 on the coating portion 15 side starts, crimping of the part of the conductor crimping portion 7 on the tip side of the conductor 13 is not yet started.

When the die 21b is further lowered from this state, the dies 21a and 21b mesh as shown in FIG. 4(c), and the conductor crimping portion 7 and the conductor 13 are completely crimped together. For example, in the case of a tubular conductor crimping portion 7, the conductor 13 is crimped into a substantially circular shape. In other words, the terminal 1 is electrically connected to the coated conductor 11.

At this time, the area where crimping begins first (a part of the rear end side of the conductor crimping portion 7) is pressed harder than the other area (a part of the front end side of the conductor crimping portion 7), so the extension (movement) of the conductor 13 is restricted compared to the other areas. Therefore, the conductor 13 preferentially extends toward the front end side, and extension toward the rear end side is suppressed. As a result, it is possible to suppress the conductor 13 from spreading between the conductor crimping portion 7 and the coating portion 15.

The front and rear ends of the dies 21a and 21b (the portions corresponding to the front and rear ends of the conductor crimping portion 7) may be tapered (not shown). In this way, the front and rear ends of the conductor crimping portion 7 can be gradually expanded in diameter after crimping (a so-called bell-mouth shape). In this case, the bell-mouth shaped portion on the rear end side causes the conductor 13 to stretch toward the rear end, but since it is only a small portion of the entire conductor crimping portion 7, it is possible to suppress the conductor 13 from expanding toward the coating portion 15 side.

As mentioned above, the compression ratio of the conductor 13 varies depending on the location of the conductor crimping portion 7. Here, it is desirable that the compression ratio of the conductor crimping portion 7 is in the range of 35 to 70%, for example. If the compression ratio is too small (i.e., strong crimping), there is a risk of the conductor 13 breaking. On the other hand, if the compression ratio is too large (i.e., weak crimping), the pull-out force of the conductor 13 becomes small, and there is a risk of the conductor 13 coming loose. In other words, it is desirable to set the compression shape and compression amount of the conductor crimping portion 7 so that even the area with the smallest compression ratio of the conductor crimping portion 7 has a compression ratio of 35% or more, and even the area with the largest compression ratio (excluding the bell-mouth portion) has a compression ratio of 70% or less.

In this way, the terminal-equipped electric wire 10 can be obtained. Furthermore, a wire harness can be obtained in which multiple terminal-equipped electric wires, including the obtained terminal-equipped electric wire 10, are integrated.

As described above, according to this embodiment, since the coated conductor 11 having the tensile member 14 inside is used, sufficient tensile strength can be ensured even with a small diameter. In addition, during crimping, the conductor 13 is preferentially deformed relative to the tensile member 14, so the conductor 13 stretches toward the front and rear ends of the conductor crimping portion 7. However, by first crimping a part of the rear end side of the conductor crimping portion 7, it is possible to suppress the stretching of the conductor 13 toward the rear end side from the front end side. Therefore, it is possible to suppress the spread of the conductor 13 at the rear end side of the conductor crimping portion 7, and to suppress the conductor 13 from being damaged due to contact with the edge of the terminal 1 or other parts.

In addition, because the conductor crimping portion 7 is tubular, the conductor 13 can be crimped reliably from the entire circumference 360°. As described above, by forming a terminal processing portion at the tip of the conductor 13, the conductor 13 can be easily inserted into the tubular portion 7a even if it is a thin conductor 13. Note that, in order to further improve the ease of inserting the conductor 13 into the conductor crimping portion 7, the rear end of the tubular portion 7a before crimping may be enlarged in diameter.

In addition, by simply changing the shape of the die 21b (conductor crimping blade die 23), it is possible to manufacture electric wires with terminals in the same process as in the conventional method. Note that the shape of the conductor crimping blade die 23 is not limited to a die shape that is entirely tapered from the rear end to the front end, as in the example shown in FIG. 4.

For example, as shown in FIG. 5(a), a straight section may be provided at the rear end of the conductor crimping blade die 23, and the diameter may be tapered from the middle of the front-rear direction toward the front end. Alternatively, as shown in FIG. 5(b), instead of forming a taper, the rear end of the conductor crimping blade die 23 may be convex in the compression direction, forming a step between the rear end and the front end. Alternatively, as shown in FIG. 5(c), the rear end of the conductor crimping blade die 23 may be convex, forming a step between the rear end and the front end, and further toward the front end than the step, a tapered shape may be formed that expands in diameter as it approaches the front end. Although not shown, the step or taper may be formed in multiple steps.

In this way, when crimping the conductor crimping portion 7 and the conductor 13, the shape of the leading end of the conductor crimping blade die 23 may be formed to protrude in the compression direction compared to the rear end so that crimping of the rear end of the conductor crimping portion 7 begins before the leading end of the conductor crimping portion 7. In either case, as described above, the leading and rear ends of the conductor crimping blade die 23 may be enlarged in diameter to correspond to the bell-mouth shape after crimping.

Second Embodiment
Next, a second embodiment will be described. Fig. 6 is a diagram showing a manufacturing process of the electric wire with terminal 10 according to the second embodiment. In the following description, the same reference numerals as in Figs. 1 to 5 are used for configurations having the same functions as those in the first embodiment, and duplicated descriptions will be omitted.

In the second embodiment, the die 21b that crimps the conductor crimping portion 7 is divided into at least two parts. For example, as shown in FIG. 6(a), the conductor crimping blade dies 23a and 23b are constructed as separate bodies. The crimping surfaces of both the conductor crimping blade dies 23a and 23b are perpendicular to the compression direction. In other words, there is no need to form a tapered shape or a stepped shape as in the first embodiment.

First, as shown in FIG. 6(a), the terminal 1 with the coated conductor wire 11 placed in the conductor crimping section 7 is set in the mold. At this time, the conductor crimping blade die 23a is placed on the rear end side of the conductor crimping section 7, and the conductor crimping blade die 23b is placed on the front end side of the conductor crimping section 7.

From this state, as shown in FIG. 6(b), only the conductor crimping blade die 23a is operated to crimp a portion of the rear end side of the conductor crimping portion 7. In other words, the die that crimps the portion of the conductor crimping portion 7 on the coating portion 15 side is operated first to crimp it.

Next, as shown in FIG. 6(c), the conductor crimping blade die 23b is operated to crimp a portion of the tip side of the conductor crimping portion 7. That is, the die for crimping the portion of the conductor crimping portion 7 on the tip side of the conductor 13 is operated later to crimp it. In this way, by changing the timing of crimping depending on the portion of the conductor crimping portion 7 rather than crimping the entire conductor crimping portion 7 all at once, it is possible to obtain the same effect as in the first embodiment.

The conductor crimping blade die 23a may be narrower in width (the vertical length of the conductor crimping portion) than the conductor crimping blade die 23b, since it is a temporary crimp near the rear end of the conductor crimping portion 7. In the illustrated example, the timing of crimping the coating portion 15 by the coating crimping blade die 25 is simultaneous with that of the conductor crimping blade die 23b, but it may also be simultaneous with that of the conductor crimping blade die 23a. The die 21b may be divided into three or more parts instead of two parts.

According to the second embodiment, it is possible to obtain the same effect as the first embodiment. In addition, by changing the crimping timing by using multiple dies, it is not necessary to change the compression rate depending on the part of the conductor crimping portion 7, and the overall compression rate of the conductor crimping portion 7 can be made approximately constant. Therefore, more appropriate compression conditions can be set.

Third Embodiment
Next, a third embodiment will be described. Fig. 7 is a diagram showing a manufacturing process of the electric wire with terminal 10 according to the third embodiment. In the third embodiment, the crimping surface of the die 21b (conductor crimping blade die 23) that crimps the conductor crimping portion 7 has a plurality of concave and convex shapes in the axial direction of the conductor crimping portion 7.

In this embodiment, the terminal 1 with the coated conductor wire 11 placed in the conductor crimping portion 7 is first set in the die as shown in FIG. 7(a). From this state, the die 21b is operated to crimp the conductor crimping portion 7 as shown in FIG. 7(b). FIG. 7(c) is an enlarged view of the Y portion in FIG. 7(b) during crimping.

As described above, the die 21b (conductor crimping blade die 23) has multiple convex portions 24a and concave portions 24b formed in the axial direction of the conductor crimping portion 7. In this case, the portion of the convex portion 24a begins to be compressed earlier than the portion of the concave portion 24b. That is, as in the first embodiment, compression of the part of the conductor crimping portion 7 corresponding to the convex portion 24a begins first, and compression of the other portion corresponding to the concave portion 24b begins later.

In this case, for example, when the conductor 13 is compressed by the protruding portion 24a on the rear end side (R in the figure), the conductor 13 tries to stretch in the front and rear directions (T, U in the figure). Similarly, when the conductor 13 is compressed by another protruding portion 24a adjacent to the protruding portion 24a on the rear end side (S in the figure), the conductor 13 tries to stretch in the front and rear directions (V, W in the figure).

At this time, part of the extension U of the conductor 13 toward the tip side associated with the preceding compression R and part of the extension V of the conductor 13 toward the rear end side associated with the compression S can be absorbed by the recess 24b, which starts compression later. On the other hand, when the compression of the conductor 13 starts by the recess 24b, the extension (movement) of the conductor 13 is restricted because the protrusion 24a is compressed more strongly. Therefore, by performing the compression R on the rear end side relatively first, it is possible to suppress the extension of the conductor 13 toward the rear (extension further rearward than the compression R) that is caused by the compression S on the tip side and the compression by the recess 24b. Therefore, the extension of the conductor 13 toward the rear end side of the conductor crimping part 7 is suppressed, and the spread between the covering part 15 can be suppressed.

According to the third embodiment, it is possible to obtain the same effect as the first embodiment. That is, in the first embodiment, the rear end side is compressed first and the front end side is compressed later, but in this embodiment, this configuration is repeated multiple times in the front-rear end direction. Therefore, although the compression rate is not constant depending on the part, it is possible to reduce the difference in compression rate depending on the part compared to the first embodiment. In addition, there is no need to divide the mold 21b into multiple parts, and the structure is simple.

Fourth Embodiment
Next, a fourth embodiment will be described. Fig. 8 is a diagram showing a manufacturing process of the electric wire with terminal 10 according to the fourth embodiment. In the fourth embodiment, the plate thickness of the conductor crimping portion 7 of the terminal 1 is not constant, and a thick portion 27 is formed on the rear end side. More specifically, in the conductor crimping portion 7 of the terminal 1 before crimping, the thickness of the rear end side (the coating portion 15 side) of the conductor crimping portion 7 is thicker than the thickness of the tip side (the tip side of the conductor 13) of the conductor crimping portion 7.

In this embodiment, first, as shown in FIG. 8(a), the terminal 1 with the coated conductor wire 11 placed in the conductor crimping portion 7 is set in a mold. At this time, the mold 21b used may be the same as that of the conventional embodiment. From this state, the mold 21b is operated to crimp the conductor crimping portion 7 as shown in FIG. 8(b).

The die 21b (conductor crimping blade die 23) crimps the entire conductor crimping portion 7 with the same amount of compression, but as described above, the thickness of the conductor crimping portion 7 on the coating portion 15 side is thicker than the thickness of the conductor crimping portion 7 on the tip side of the conductor 13. Therefore, in the area corresponding to the thick portion 27, the amount of compression of the conductor 13 is greater by the difference in thickness.

In other words, compression begins first in the area corresponding to the thick portion 27, and compression of other areas follows later. Therefore, as in the first embodiment, when areas of the conductor crimping portion 7 other than the thick portion 27 are compressed, the extension (movement) of the conductor 13 is restricted in a portion of the rear end side of the conductor crimping portion 7 where the thick portion 27 is formed. This makes it possible to suppress further extension of the conductor 13. This prevents the conductor 13 from extending toward the rear end side of the conductor crimping portion 7, and prevents it from spreading between the conductor 13 and the coating portion 15.

According to the fourth embodiment, the same effects as those of the first embodiment can be obtained. In addition, there is no need to divide the die 21b into multiple parts, the structure is simple, and the entire conductor crimping portion 7 can be made to a substantially constant height.

Although the embodiment of the present invention has been described above with reference to the attached drawings, the technical scope of the present invention is not limited to the above-mentioned embodiment. It is clear that a person skilled in the art can come up with various modified or revised examples within the scope of the technical ideas described in the claims, and it is understood that these also naturally fall within the technical scope of the present invention.

For example, the conductor crimping portion 7 is formed in a tubular shape, but is not limited to this. For example, a terminal 1a in which the conductor crimping portion 7 and the coating crimping portion 9 are both open barrel shaped may be used, as in the terminal-attached electric wire 10a shown in FIG. 9. Note that the terminal-attached electric wire 10a has a crimping form corresponding to the first embodiment, but any of the second to fourth embodiments may be combined with the terminal-attached electric wire 10a. In this way, the form of the conductor crimping portion 7 is not particularly limited, and may be another form, such as an overlap type. It goes without saying that the above-mentioned embodiments can be combined with each other.

1, 1a... Terminal 3... Terminal body 5... Crimping portion 7... Conductor crimping portion 7a... Tubular portion 9... Coating crimping portion 10, 10a... Electric wire with terminal 11... Covered conductor wire 13... Conductor wire 13a... Elemental wire 14... Tensile strength member 15... Covering portion 21a, 21b... Molds 23, 23a, 23b... Conductor crimping blade die 24a... Convex portion 24b... Concave portion 25... Coating crimping blade die 27... Thick portion 101... Terminal 103... Terminal body 107... Conductor crimping portion 111... Covered conductor wire 113... Conductor wire 113a... Elemental wire 114... Tensile strength member 115... Covering portion

Claims (8)

A method for manufacturing an electric wire with a terminal in which a coated conductor wire and a terminal are electrically connected, comprising the steps of:
The covered conductor wire includes a tension member, a conductor wire, and a covering portion that covers the tension member and the conductor wire,
the terminal has a conductor crimping portion to which the conductor exposed from the coating at the tip of the coated conductor is crimped,
When the conductor crimping portion and the conductor are crimped, crimping of a part of the conductor crimping portion on the coating portion side is started before crimping of a part of the conductor crimping portion on the tip side of the conductor in the longitudinal direction of the coated conductor, so that a compression amount of the part of the conductor crimping portion on the coating portion side during crimping is made larger than a compression amount of the part of the conductor crimping portion on the tip side of the conductor,
a method for manufacturing an electric wire with a terminal, comprising the steps of: deforming the conductor more than the tensile body, thereby extending the conductor toward the tip side of the conductor crimping portion, and first crimping a portion of the rear end side of the conductor crimping portion, which is a part of the conductor crimping portion on the coating side, thereby suppressing extension of the conductor further toward the rear end side. The method for manufacturing an electric wire with terminal according to claim 1, characterized in that the die for crimping the conductor crimping portion is formed so that the portion for crimping the part of the conductor crimping portion on the coating portion side protrudes in the compression direction compared to the portion for crimping the part of the conductor crimping portion on the tip side of the conductor. The method for manufacturing an electric wire with terminal according to claim 1 or 2, characterized in that the die for crimping the conductor crimping portion has multiple concave and convex shapes in the longitudinal direction of the conductor crimping portion. The method for manufacturing an electric wire with terminal according to claim 1, characterized in that the die for crimping the conductor crimping portion is divided into at least two parts, and the die for crimping the part of the conductor crimping portion on the coating side is operated first to crimp, and the die for crimping the part of the conductor crimping portion on the tip side of the conductor is operated later to crimp. The method for manufacturing an electric wire with a terminal according to any one of claims 1 to 3, characterized in that, in the conductor crimping portion of the terminal before crimping, the thickness of the conductor crimping portion on the side of the covering portion is thicker than the thickness of the conductor crimping portion on the tip side of the conductor. 6. The method for manufacturing an electric wire with terminal according to claim 1, wherein the compression amount of a part of a rear end portion of the conductor crimping portion is greater than other portions and is greater than the compression amount of a tip side of the conductor crimping portion and a central portion of the conductor crimping portion . 7. The method for manufacturing an electric wire with a terminal according to claim 6, wherein a thickness of the conductor crimping portion on the side of the covering portion is greater than a thickness of the conductor crimping portion on the side of the tip of the conductor. A method for producing a wire harness, comprising integrating a plurality of electric wires with terminals produced by the method for producing an electric wire with terminal according to claim 6 or 7.

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