JP2023152377A - Manufacturing method of crimp structure - Google Patents

Abstract

To provide a manufacturing method of a crimp structure in which a conductor and a crimp member are crimped, which has good conductivity and can suppress the occurrence of contact corrosion of different metals.SOLUTION: A manufacturing method of a crimp structure includes a step of crimping a conductor 10 and a plurality of crimping members 20 in a state where the conductor 10 of an electric wire is arranged between the plurality of crimping members 20, the conductor 10 and each of the plurality of crimp members 20 contain the same metal element, each of the plurality of crimp members 20 is formed by casting, and in a cross section perpendicular to the longitudinal direction of the conductor 10, the conductor 10 and the plurality of crimping members 20 are crimped such that the porosity of the portion surrounded by the plurality of crimping members 20 is 2% or less.SELECTED DRAWING: Figure 1

Description

The present invention relates to a method for manufacturing a crimp structure.

Terminals are used in products such as wire harnesses to connect electric wires and equipment. BACKGROUND ART In recent years, aluminum is increasingly being used for electric wires in order to reduce the weight of vehicles and improve fuel efficiency.

Patent Document 1 discloses a wire harness connection structure for connecting two or more electric wires whose core wires have different tensile strengths using a joint terminal. One of the electric wires has an aluminum core, and the other has a copper core. In the above connection structure, the core wires of two or more electric wires are covered together with a joint terminal, and the joint terminal is compressed at a high compression rate from the base end toward the distal end.

Japanese Patent Application Publication No. 2015-50082

In the wire harness of Patent Document 1, an electric wire whose core wire is aluminum and an electric wire whose core wire is copper are used. In such a wire harness, contact corrosion between different metals of copper and aluminum may occur due to water adhering to the core wire due to dew condensation. Therefore, in order to suppress the contact corrosion of dissimilar metals, additional elements such as waterproofing or anticorrosion treatment of the dissimilar metal contact portions are required, which may lead to an increase in the size and cost of the parts.

In addition, in the wire harness of Patent Document 1, since aluminum and copper are used for the core wire, contact corrosion of different metals occurs between the core wire and the terminal regardless of whether aluminum or copper is used for the terminal. There is a risk.

The present invention has been made in view of the problems of the prior art. An object of the present invention is to provide a method for manufacturing a crimping structure in which a conductor and a crimping member are crimped, which has good conductivity and can suppress the occurrence of contact corrosion of different metals.

A method for manufacturing a crimping structure according to an aspect of the present invention includes the step of crimping a conductor and a plurality of crimping members with the conductor of an electric wire disposed between the plurality of crimping members. In the above method, the conductor and each of the plurality of crimp members include the same metal element. Each of the plurality of crimping members is formed by casting, and the conductor and the plurality of crimping members are arranged so that the porosity of the portion surrounded by the plurality of crimping members is 2% or less in a cross section perpendicular to the longitudinal direction of the conductor. and are crimped.

According to the present invention, it is possible to provide a method for manufacturing a crimping structure in which a conductor and a crimping member are crimped, which has good conductivity and can suppress the occurrence of contact corrosion of different metals.

It is a front view showing an example of the manufacturing method of the crimp structure concerning this embodiment. It is a top view showing an example of the manufacturing method of the crimp structure concerning this embodiment. FIG. 2 is a front view showing an example of a crimping member according to the present embodiment. FIG. 2 is a plan view showing an example of a crimping member according to the present embodiment. It is a side view showing an example of the crimp member concerning this embodiment. It is a front view showing an example of the compression jig concerning this embodiment. It is a top view showing an example of the compression jig concerning this embodiment. It is a graph showing the relationship between the space between crimping jigs and the porosity. It is a graph showing the relationship between porosity and resistance value.

Hereinafter, a method for manufacturing a crimp structure according to this embodiment will be described in detail using the drawings. Note that the dimensional ratios in the drawings are exaggerated for convenience of explanation and may differ from the actual ratios. Further, in this embodiment, the radial direction of the conductor is assumed to be the X direction and the Y direction, and the longitudinal direction of the conductor perpendicular to the X direction and the Y direction is assumed to be the Z direction.

As shown in FIGS. 1 and 2, the method for manufacturing a crimping structure according to the present embodiment includes crimping a conductor 10 and a plurality of crimping members 20 in a state in which a conductor 10 of an electric wire is arranged between a plurality of crimping members 20. It includes the process of By crimping the conductor 10 and the plurality of crimping members 20, the conductor 10 and the plurality of crimping members 20 can be electrically and mechanically coupled.

The electric wire may include a conductor 10 and an insulating layer coated on the outer surface of the conductor 10. The number of electric wire conductors 10 to be crimped is not particularly limited, and may be one, two, three, four, five, or six or more.

The conductor 10 includes a plurality of wires 11 in this embodiment. However, the conductor 10 may be composed of only one strand 11, or may be a collective stranded wire in which a plurality of strands 11 are bundled. Further, the conductor 10 may be composed of only one stranded wire, or may be a composite stranded wire composed of a plurality of aggregated stranded wires bundled together. The diameters of the plurality of wires 11 may be the same or different. If the diameters of each composition are the same, the strands 11 may be difficult to break during crimping.

From the viewpoint of electrical conductivity, the conductor 10 may contain at least one metal selected from the group consisting of gold, silver, copper, aluminum, magnesium, and alloys containing these metal elements. Among these, from the viewpoint of lightweight, it is preferable that the conductor 10 contains aluminum.

The insulating layer can suppress electrical leakage from the conductor 10. The insulating layer may contain a resin composition. The resin composition may include thermoplastic resins such as polyolefins and polyvinyl chloride. Thermoplastic resins such as these have excellent flexibility and insulation properties.

In this embodiment, two pressure bonding members 20 having the same shape are used. In this embodiment, an example is described in which the crimp member 20 is a joint terminal. Each of the plurality of crimping members 20 includes a curved portion 21 and engaging portions 22 provided at both ends of the curved portion 21, as shown in FIGS. 3 to 5. Then, by engaging the two crimp members 20 at the engaging portions 22, a space for arranging the conductor 10 can be formed in a portion surrounded by the two crimp members 20.

The curved portion 21 has an arch shape when viewed from the Z direction, and extends in the Z direction. The inner diameter D21 of the curved portion 21 may be, for example, 1 mm or more and 100 mm or less, although it depends on the diameter and number of conductors 10 arranged inside. The inner diameter D21 may be 3 mm or more, 5 mm or more, or 10 mm or more. Further, the inner diameter D21 may be 50 mm or less, 30 mm or less, or 20 mm or less.

The outer diameter D22 of the curved portion 21 is larger than the inner diameter D21, and may be, for example, 1 mm or more and 150 mm or less, depending on the diameter and number of conductors 10 arranged inside. The outer diameter D22 may be 5 mm or more, 10 mm or more, 15 mm or more, or 20 mm or more. Further, the outer diameter D22 may be 100 mm or less, 50 mm or less, or 30 mm or less.

The radial thickness T21 of the curved portion 21 may be 1 mm or more and 20 mm or less. By setting the thickness T21 to 1 mm or more, the strength of the terminal can be improved. Furthermore, by setting the thickness T21 to 20 mm or less, crimping can be facilitated. The thickness T21 may be 3 mm or more, or 5 mm or more. Moreover, the thickness T21 may be 15 mm or less, or may be 10 mm or less.

In each crimp member 20, the width Y21 between the engaging portions 22 may be the same as the inner diameter D21 described above. That is, the width Y21 may be 1 mm or more and 100 mm or less. The width Y21 may be 3 mm or more, 5 mm or more, or 10 mm or more. Further, the width Y21 may be 50 mm or less, 30 mm or less, or 20 mm or less.

The radial width Y22 of the engaging portion 22 may be the same as the thickness T21 described above, or may be a value smaller than the thickness T21. That is, the width Y22 may be 1 mm or more and 20 mm or less. The width Y22 may be 3 mm or more, or may be 5 mm or more. Moreover, the width Y22 may be 15 mm or less, or may be 10 mm or less.

The length Z21 of the pressure bonding member 20 in the Z direction may be 10 mm or more and 100 mm or less. When the length Z21 is 10 mm or more, a sufficient crimp portion of the conductor 10 can be secured. Furthermore, by setting the length Z21 to 100 mm or less, handling becomes easier. The length Z21 may be 20 mm or more, or may be 30 mm or more. Moreover, the length Z21 may be 70 mm or less, or may be 40 mm or less.

As shown in FIG. 5, the engaging part 22 includes a plurality of convex parts 23 protruding from the curved part 21 when viewed from the Y direction, and a plurality of concave parts 24 provided between the plurality of convex parts 23. There is. The convex portions 23 and the concave portions 24 are arranged alternately in the Z direction. Then, by inserting the convex part 23 of the other crimp member 20 into the concave part 24 of one crimp member 20, the convex part 23 and the concave part 24 engage with each other, so that the crimp members 20 are bonded together during crimping. It is possible to suppress slipping and movement in the Z direction.

The width of the convex portion 23 in the Z direction may be 1 mm or more, 2 mm or more, or 3 mm or more. Further, the width of the convex portion 23 in the Z direction may be 10 mm or less, 8 mm or less, or 6 mm or less. The widths of the plurality of protrusions 23 may be the same or different. In this embodiment, the crimping member 20 has four convex portions 23, and the width Z22 of the convex portion 23 at one end in the Z direction is longer than the width Z23 of the other three convex portions 23. ing.

The width of the recess 24 in the Z direction may be 1 mm or more, 2 mm or more, or 3 mm or more. Further, the width of the recess 24 in the Z direction may be 10 mm or less, 8 mm or less, or 6 mm or less. The widths of the plurality of recesses 24 may be the same or different. In this embodiment, the crimping member 20 has four recesses 24, and the width Z24 of the recess 24 at one end in the Z direction is longer than the width Z25 of the other three recesses 24.

The length X21 of the protrusion 23 and the recess 24 in the X direction (the height of the protrusion 23 or the depth of the recess 24) may be 1 mm or more, 3 mm or more, or 5 mm or more. Good too. Further, the length X21 may be 10 mm or less, 8 mm or less, or 7 mm or less.

Although the convex portion 23 and the concave portion 24 have an angular shape when viewed from the Y direction in this embodiment, they are not limited to such a shape, and may have a shape with rounded corners. Further, the number of the convex portions 23 and the concave portions 24 is not particularly limited, and may be two or more, or three or more, for example. Further, the number of the convex portions 23 and the concave portions 24 may be, for example, 100 or less, 50 or less, 10 or less, or 5 or less.

Further, the plurality of crimping members 20 only need to include two or more crimping members 20, and may include three or more crimping members 20, or four or more crimping members 20. The fewer the number of crimping members 20, the easier the handling. On the other hand, the larger the number of crimping members 20, the more complex the shape can be accommodated. Moreover, by using a plurality of crimping members 20, arbitrary locations on the conductor 10 can be crimped. That is, it is possible to crimp not only the axial end portions of the conductor 10 but also the axial center portion of the conductor 10. Thereby, it is also possible to crimp a branch portion of the conductor 10 that branches into two or more. Each of the plurality of crimping members 20 may have the same shape or may have different shapes. Furthermore, the shape of the combined body in which the plurality of crimping members 20 are combined may be a polygonal cylinder instead of a cylinder.

In the state where the plurality of crimping members 20 are engaged, the cross-sectional area of the plurality of crimping members 20 cut along the X-Y plane is the cross-sectional area of the conductor 10 crimped by the plurality of crimping members 20 cut along the X-Y plane. May be larger than . This makes it easier for current to flow from one conductor 10 to the other conductor 10 via the crimp member 20.

The conductor 10 and each of the plurality of crimp members 20 contain the same metal element. When the conductor 10 and the plurality of crimping members 20 are crimped using dissimilar metals, contact corrosion of dissimilar metals is likely to occur due to the presence of water between the dissimilar metals. Therefore, in order to suppress the contact corrosion of dissimilar metals, it is necessary to perform anti-corrosion processing such as providing an anti-corrosion coating between the conductor 10 and the plurality of crimping members 20 so that moisture is less likely to adhere thereto. However, in this embodiment, the conductor 10 and each of the plurality of crimping members 20 contain the same metal element. Therefore, contact corrosion between different metals is less likely to occur between the conductor 10 and the plurality of crimping members 20. The metal element is preferably aluminum from the viewpoint of lightweight.

From the viewpoint of electrical conductivity, each of the plurality of crimping members 20 may contain at least one metal selected from the group consisting of gold, silver, copper, aluminum, magnesium, and alloys containing these metal elements. Among these, from the viewpoint of lightweight, each of the plurality of pressure bonding members 20 preferably contains aluminum.

Each of the plurality of crimp members 20 is formed by casting. Mechanical properties can be improved by forming each of the plurality of crimping members 20 by casting rather than by drawing like a general terminal. For example, common wrought aluminum materials tend to have poorer stress relaxation properties at terminals than wrought copper materials. However, by using a cast aluminum material for the crimp member 20, stress relaxation characteristics can be improved compared to the case where a wrought copper material is used.

Casting also allows for more flexible shapes than stretching. Therefore, for example, in order to remove an oxide film on the surface of the conductor 10, an oxide film removal structure such as a protrusion can be easily formed. With such a removal structure, the oxide film can be actively removed during pressure bonding, and the contact resistance can also be reduced. Moreover, since the above-mentioned removal structure can be formed by casting without going through a plurality of steps, the work load can be reduced compared to the case where the crimp member 20 is manufactured by stretching.

The conductor 10 and the plurality of crimping members 20 are crimped by a plurality of compression jigs 30. In this embodiment, the plurality of compression jigs 30 include two compression jigs 30 having the same shape. However, the shapes of the plurality of compression jigs 30 may be different from each other. As shown in FIGS. 6 and 7, the compression jig 30 includes a rectangular base 31 and a notch 32 in which a portion of the base 31 is cut out.

The length X31 of the base portion 31 in the X direction may be, for example, 10 mm or more and 100 mm or less. The length X31 may be 20 mm or more, or may be 25 mm or more. Moreover, the length X31 may be 70 mm or less, or may be 40 mm or less.

The length Y31 of the base portion 31 in the Y direction may be, for example, 50 mm or more and 300 mm or less. The length Y31 may be 60 mm or more, or may be 70 mm or more. Moreover, the length Y31 may be 200 mm or less, or may be 100 mm or less.

The length Z31 of the base portion 31 in the Z direction corresponds to the compression width of the pressure bonding member 20. The length Z31 may be shorter than the length Z21 of the pressure bonding member 20 in the Z direction. The length Z31 may be 40% or more, 50% or more, or 60% or more of the length Z21. Further, the length Z31 may be 90% or less, 80% or less, or 70% or less of the length Z21. The length Z31 may be 10 mm or more and 100 mm or less.

The cutout portion 32 has a trapezoidal column shape. Therefore, when the compression jigs 30 are closed, a hexagonal space is formed by the notch 32 between the two compression jigs 30 when viewed from the Z direction. The hexagonal space can prevent the force for crimping the conductor 10 from being biased to one side, so that the conductor 10 can be crimped uniformly. The shape between the compression jigs 30 may not be hexagonal but may be a heptagonal or more polygonal shape. Even with such a shape, uneven crimping of the conductor 10 can be suitably suppressed.

The length Y32 of the upper base of the notch 32 when viewed from the Z direction may be, for example, 1 mm or more and 50 mm or less. The length Y32 may be 3 mm or more, 5 mm or more, or 10 mm or more. Further, the length Y32 may be 30 mm or less, or may be 20 mm or less.

The length Y33 of the lower base of the notch 32 when viewed from the Z direction may be longer than the length Y32 of the upper base. The length Y33 may be, for example, 1 mm or more and 100 mm or less. The length Y33 may be 3 mm or more, 5 mm or more, or 10 mm or more. Moreover, the length Y33 may be 50 mm or less, or may be 30 mm or less.

The height X32 of the notch 32 when viewed from the Z direction may be, for example, 1 mm or more and 50 mm or less. The height X32 may be 3 mm or more, 5 mm or more, or 10 mm or more. Moreover, the height X32 may be 30 mm or less, or may be 20 mm or less.

Next, how the conductor 10 and the plurality of crimping members 20 are crimped by the method for manufacturing a crimping structure according to the present embodiment will be described with reference to FIGS. 1 and 2.

First, the conductor 10 is placed between a plurality of crimping members 20. Then, the conductor 10 and the plurality of crimping members 20 are arranged in a space formed by the notch 32 of the compression jig 30. Each of the plurality of crimping members 20 is arranged perpendicular to the Y direction, which is the arrangement direction of the compression jigs 30. That is, the plurality of crimping members 20 are arranged such that the direction in which the plurality of crimping members 20 face each other (X direction) is perpendicular to the direction in which the plurality of compression jigs 30 face each other (Y direction).

Next, the compression jig 30 applies pressure to the plurality of compression bonding members 20 from the outside. Thereby, the conductor 10 and the plurality of crimp members 20 are crimped together with the conductor 10 disposed between the plurality of crimp members 20 .

Each of the plurality of crimp members 20 includes an engaging portion 22 in which the plurality of crimp members 20 engage with each other, and when each of the plurality of crimp members 20 is engaged with the engaging portion 22, the conductor 10 and the plurality of crimp members 20 may be crimped. Thereby, the crimping members 20 are engaged with each other by the engaging portions 22, so that it is possible to suppress the crimping members 20 from sliding and moving in the Z direction during crimping.

In this method, the conductor 10 and the plurality of crimp members 20 are crimped so that the porosity of the portion surrounded by the plurality of crimp members 20 is 2% or less in a cross section perpendicular to the longitudinal direction of the conductor 10 . When the porosity after crimping is 2% or less, the electrical resistance between the conductor 10 and the crimping member 20 becomes small, so a crimping structure with good electrical conductivity can be provided. The porosity can be obtained by analyzing the image of a cross section perpendicular to the longitudinal direction of the conductor 10 in the crimping structure and quantifying the proportion of voids between the wires 11 in the area surrounded by the plurality of crimping members 20. can.

As explained above, the method for manufacturing a crimping structure according to the present embodiment includes the step of crimping the conductor 10 and the plurality of crimping members 20 in a state where the conductor 10 of the electric wire is arranged between the plurality of crimping members 20. There is. The conductor 10 and each of the plurality of crimp members 20 contain the same metal element. Each of the plurality of crimp members 20 is formed by casting. In a cross section perpendicular to the longitudinal direction of the conductor 10, the conductor 10 and the plurality of crimp members 20 are crimped so that the porosity of the portion surrounded by the plurality of crimp members 20 is 2% or less.

Since the conductor 10 and each of the plurality of crimp members 20 contain the same metal element, contact corrosion between different metals is unlikely to occur between the conductor 10 and the plurality of crimp members 20. In the crimp structure, since the porosity of the portion surrounded by the plurality of crimp members 20 is 2% or less, the crimp structure has good electrical conductivity. Therefore, the method according to the present embodiment provides a crimping structure in which the conductor 10 and the crimping member 20 are crimped, which has good conductivity and can suppress the occurrence of contact corrosion of different metals. I can do it.

Further, each of the plurality of crimping members 20 is formed by casting. Therefore, since it has superior mechanical properties compared to terminals formed by general stretching, the crimping member 20 is deformed during crimping, and the conductor 10 is prevented from being excessively crimped and cut. I can do it. In addition, since the crimping member 20 is formed by casting, it can be applied even to complex shapes, and can be applied not only to joint terminals but also to structural members such as battery pack casings and inverter cases. be able to.

Hereinafter, the present embodiment will be described in more detail with reference to Examples and Comparative Examples, but the present embodiment is not limited to these Examples.

[Example 1]
First, the engaging portions of the two crimp members were engaged with each other while the conductor of one electric wire was sandwiched between the two crimp members. As the conductor, an electric wire containing an aluminum wire was used. Moreover, a press-bonding member made of cast aluminum was used as the press-bonding member. As shown in FIGS. 3 to 5, each crimp member has an inner diameter D21 of 13.6 mm, an outer diameter D22 of 26 mm, a thickness T21 of 6.2 mm, a width Y21 of 13.6 mm, and a width Y22 of 5.85 mm. be. Further, each crimping member has a length X21 of 6 mm, a length Z21 of 36 mm, a width Z22 of 6 mm, a width Z23 of 4 mm, a width Z24 of 6 mm, and a width Z25 of 4 mm.

The conductor produced as described above and the two crimping members were placed in the space formed by the notches of the two compression jigs, as shown in FIGS. 8 and 9. At this time, the two crimping members were arranged so that the direction in which the two crimping members faced each other was perpendicular to the direction in which the two compression jigs faced each other. Each compression jig has a length X31 of 30 mm, a height X32 of 10.83 mm, a length Y31 of 80 mm, a length Y32 of 12.5 mm, and a length Y33 of 80 mm, as shown in FIGS. The length Z31 is 24 mm.

Next, as shown in FIGS. 1 and 2, with one compression jig fixed, the other compression jig is connected between the surface of one compression jig and the surface of the other compression jig. The conductor was moved and the plurality of crimping members were crimped together until the space L between them became 0 mm. That is, the conductor and the plurality of crimping members were crimped with the conductor of the electric wire disposed between the plurality of crimping members.

[Example 2]
A crimp structure was produced in the same manner as in Example 1 except that the space L was changed to 1 mm.

[Example 3]
A crimp structure was produced in the same manner as in Example 1 except that the space L was changed to 2 mm.

[Example 4]
A crimp structure was produced in the same manner as in Example 1 except that the space L was changed to 3 mm.

[Comparative example 1]
A crimp structure was produced in the same manner as in Example 1 except that the space L was changed to 5 mm.

[evaluation]
The porosity and resistance value of the crimped structure produced as described above were measured.

(porosity)
The porosity was determined by image analysis of a cross section perpendicular to the longitudinal direction of the conductor in the crimped structure, and the porosity of the portion surrounded by a plurality of crimped members was quantified. Table 1 and FIG. 8 show the relationship between space L and porosity.

(Resistance value)
The resistance value was determined by measuring the electrical resistance between the wire and the crimping member in the crimping structure. Table 1 and FIG. 9 show the relationship between porosity and resistance value.

As shown in Table 1 and FIGS. 8 and 9, by compressing the crimping member and the conductor so that the space L is 3 mm or less, the electrical resistance between the wire and the crimping member is stably maintained at 200 μΩ or less. I was able to do that. In other words, by reducing the porosity of the conductor to 2% or less, the electrical resistance between the wire and the crimping member can be stably kept at 200 μΩ or less, proving that the crimping structure has good electrical conductivity. .

Although this embodiment has been described above, this embodiment is not limited to these, and various modifications can be made within the scope of the gist of this embodiment.

10 Conductor 20 Crimp member 22 Engagement part

Claims (3)

crimping the conductor and the plurality of crimping members in a state where the conductor of the electric wire is arranged between the plurality of crimping members,
Each of the conductor and the plurality of crimping members contains the same metal element,
Each of the plurality of crimp members is formed by casting,
Manufacturing a crimping structure in which the conductor and the plurality of crimping members are crimped so that the porosity of the portion surrounded by the plurality of crimping members is 2% or less in a cross section perpendicular to the longitudinal direction of the conductor. Method. The method for manufacturing a crimp structure according to claim 1, wherein the metal element is aluminum. Each of the plurality of crimp members includes an engaging portion where the plurality of crimp members engage with each other,
3. The method of manufacturing a crimping structure according to claim 1, wherein the conductor and the plurality of crimping members are crimped together while each of the plurality of crimping members is engaged with the engaging portion.

Images