Crimp terminal, electric wiring with terminal, and manufacturing method of the same

Abstract

To obtain a crimp terminal in which burr hardly occurs when connecting a wiring by fastening processing.SOLUTION: A crimping terminal 1 is also constructed by a metal material by integrating a terminal connection part 10 and an electric wiring connection part 20. The electric wiring connection part 20 is constructed by performing so-called H-cut processing that an outer periphery at both end parts in a y-direction in a toric cross section is locally and linearly cut along a z-direction. Cut parts 20A and 20B cut are formed in parallel with each other along the z-direction, and both end part sides along the y-direction of the electric wire connection part are locally thinned thin film parts 21A and 21B. The thin film parts 21A and 21B are provided at a part where barr in the electric wiring connection part 20 is formed, and therefore a projection amount along the y-direction becomes small even if the burr is formed.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a closed barrel type crimp terminal, a wire with a terminal using the same, and a method for manufacturing the same.

Background Art

[0002] When wiring is used by being connected to an electrical component in an automobile or the like, the end of the wiring is connected to a terminal, and then the terminal is used after being connected in various forms. At this time, a crimp terminal in which the wiring (conductive wire) is crimped and fixed to the terminal is preferably used.

[0003] FIG. 5 is a side view (a) showing the structure of such a crimp terminal 9 and a cross-sectional view (b) in the A-A direction thereof. Here, the side view (a) shows a side along the extending direction of the wiring connected to the crimp terminal 9, and the cross-sectional view (b) shows a cross-section perpendicular to this extending direction. The left side of the crimp terminal 9 in FIG. 5(a) is a male type terminal and is a terminal connection portion 10 having a shape that is fitted and connected to other terminals.

[0004] The right side in FIG. 5(a) is a closed barrel type wire connection portion 90 having a closed annular shape (cylindrical shape) as shown in the cross-section of FIG. 5(b). The terminal connection portion 10 and the wire connection portion 90 are integrally formed of a metal material such as aluminum or copper having low electrical resistance and capable of being processed by plastic deformation.

[0005] FIG. 6 is a side view corresponding to FIG. 5(a) showing the process of connecting the wiring 100 to the crimp terminal 9. The x-direction, y-direction, and z-direction are defined as shown in the figure. The x-direction is the extending direction of the wiring 100 (the first direction), and the z-direction (vertical direction) is the pressing direction during caulking (the second direction). Here, the wiring 100 is composed of a core wire (electric wire) 100A formed by bundling a large number of thin-diameter conductive wires and covered with an insulating coating layer 100B, and the coating layer 100B is removed and exposed at one end thereof. As shown in FIG. 6(b), with the exposed core wire 100A inserted into the internal space of the wire connection portion 90, as shown in FIG. 6(c), pressure is applied to the wire connection portion 90 so as to compress it in the vertical direction (z-direction) in the figure to plastically deform (caulk) the wire connection portion 90, whereby the core wire 100A (wiring 100) is fixed to the wire connection portion 90.

[0006] In order to realize the state of FIG. 6(c), a jig (crimping device) for pressing and deforming the wire connection portion 90 from the state of FIG. 6(b) is used. At this time, after the crimp terminal 9 and the wiring 100 are formed into the form of FIG. 6(c), it is necessary to remove them from this jig in the same state. Patent Document 1 describes the structure of a crimping device that facilitates such an operation.

[0007] FIG. 7 is a cross-sectional view showing in detail the cross-sectional shapes before (a) and after (b) pressing (caulking) such a wire connection portion 90 corresponding to the cross-section of FIG. 5(b). Here, an upper die (the first die) 210 and a lower die (the second die) 220 that sandwich the wire connection portion 90 from the upper side (positive z-direction side) and the lower side (negative z-direction side) are used respectively. Here, the lower die 220 is fixed, and caulking is performed by pressing the upper die 210 downward.

[0008] As described above, the core wire 100A is composed of a large number of bundled conductors, but here it is simplified and shown hatched as a continuous body. Here, in the upper mold (first mold) 210, there is an upper contact portion 211 that protrudes downward (negative z-direction) particularly at the center and contacts the wire connection portion 90 from above in the state before clamping, an upper mold convex portion (first convex portion) 212 that protrudes downward on the left side of the wire connection portion 90, and an upper mold concave portion (first concave portion) 213 formed at a position symmetric to the upper mold convex portion 212 with the wire connection portion 90 interposed therebetween. Also in the lower mold 220, a lower contact portion 221, a lower mold convex portion (second convex portion) 222, and a lower mold concave portion (second concave portion) 223 are formed symmetrically with the upper contact portion 211, the upper mold convex portion 212, and the upper mold concave portion 213 in the upper mold 210 in the up-down and left-right directions. In FIG. 7(a), the shape of the wire connection portion 90 is the same as that in FIG. 5(b), but in this state, the wire connection portion 90 is clamped and fixed by the upper contact portion 211 and the lower contact portion 221 (fixing step).

[0009] In this state, the upper mold 210 can be pressed downward to perform a clamping process (pressing step). In the subsequent shape (FIG. 7(b)), the wire connection portion 90 and the core wire 100A are deformed into shapes corresponding to the inner surfaces of the upper mold 210 and the lower mold 220, whereby the core wire 100A is fixed to the wire connection portion 90 (crimp terminal 9). At this time, as shown in FIG. 7, by making the upper mold 210 and the lower mold 220 have a symmetric configuration in the y-direction and the z-direction, this clamping process can be stably performed.

Prior Art Documents

Patent Documents

[0010]

Patent Document 1

Disclosure of the Invention

Problems to be Solved by the Invention

[0011] After the pressing process is performed in this manner, as shown in region B in FIG. 7(b), burrs 91 that protrude on both sides in the left-right direction (y direction) and are thin in the z direction are formed on the deformed wire connection portion 90. FIG. 8 is a top view seen from the positive z direction showing the shape of the wire 900 with terminals in a state where the crimp terminal 9 after caulking with such burrs 91 formed is connected. Here, a line corresponding to the shape of the wire connection portion 90 after caulking in FIG. 7(b) (corresponding to the inner surface shapes of the upper die 210 and the lower die 220) is shown by a dotted line. The burrs 91 are formed at both ends in the y direction (the third direction) of the pressed wire connection portion 90. Here, actually, in FIG. 7, the upper convex portion 212 and the lower convex portion 222 are formed to have a certain length in the direction perpendicular to the paper surface (x direction), and in FIG. 8, corresponding to the outside of the ends of the upper convex portion 212 and the lower convex portion 222 in the x direction, the burrs 91 spread particularly widely on both end sides in the x direction.

[0012] When pressing and deforming (caulking) a wire connection portion having a closed cylindrical cross-sectional shape (closed barrel type) between the upper die and the lower die, burrs are likely to occur at the boundary between the upper die and the lower die in this way. Alternatively, as long as the volume of the metal material constituting the wire connection portion is kept constant during the deformation (compression) of the wire connection portion having such a closed shape, pressing is performed under the condition that such burrs are generated, and the metal material (wire connection portion) can be deformed and caulked by deforming the excess metal material into burrs during deformation. Therefore, when caulking is performed by combining the upper die and the lower die as described above, burrs are inevitably likely to be formed in this way.

[0013] Actually, the crimp terminal 9 in the form of a wire with terminals as described above is incorporated into a connector housing made of a resin material and used. At this time, the above-mentioned crimp terminal 9 is inserted, fitted, and fixed into a housing portion (connector housing cavity) provided in the connector housing. In this case, in the crimp terminal 9 (wire with terminals) in which the burr 91 is formed in this way, the inner surface of the connector housing cavity interferes with the burr 91, which becomes an obstacle to this operation. Therefore, an operation of removing the burr 91 after caulking is required. For this reason, a crimp terminal in which burrs are less likely to occur when wiring is connected by caulking is required.

[0014] The present invention has been made in view of such a situation, and an object thereof is to solve the above problems.

Means for Solving the Problems

[0015] The crimp terminal of the present invention is composed of a metal material, and in a state where a wire extending along the first direction is accommodated in a substantially cylindrical internal space having a central axis along the first direction, it is deformed by being pressed along a second direction perpendicular to the first direction, and the crimp terminal includes a wire connection portion for fixing the wire. In a cross section perpendicular to the first direction, the wire connection portion includes a thin-walled portion in which the thickness of the metal material constituting the outer wall of the closed substantially cylindrical shape is locally thinned in the circumferential direction at an end along a third direction perpendicular to the second direction. The thin-walled portions may be respectively formed at both ends of the wire connection portion along the third direction. In a cross section perpendicular to the first direction, the wire connection portion may have a shape in which a region including an end along the third direction on the outer wall is removed along the second direction. The wire with terminals of the present invention has the wire fixed to the wire connection portion of the crimp terminal. The manufacturing method of the wire with terminal of the present invention is a manufacturing method of a wire with terminal in which the wire is fixed to the crimp terminal. In a state where the wire is accommodated in the internal space of the wire connection part, on one side and the other side along the second direction rather than the thin part, a first mold and a second mold that respectively contact the wire connection part are brought into contact with the wire connection part and fixed. A fixing step; a pressing step of pressing the first mold and the second mold from the state fixed in the fixing step to the other side and the one side in the second direction, respectively, to deform the wire connection part and fix the wire connection part and the wire. The first mold includes a first convex portion that is located on one side in the third direction when viewed from the wire connection portion in the fixing step and protrudes toward the other side in the second direction. The second mold includes a second convex portion that is located on the other side in the third direction when viewed from the wire connection portion in the fixing step and protrudes toward the one side in the second direction. A first concave portion for guiding the second convex portion in the pressing step may be provided in the first mold, and a second concave portion for guiding the first convex portion in the pressing step may be provided in the second mold.

Advantages of the Invention

[0016] Since the present invention is configured as described above, it is possible to obtain a crimp terminal in which burrs are less likely to occur when connecting wiring by caulking.

Brief Description of the Drawings

[0017]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Embodiments for Carrying Out the Invention

[0018] The crimp terminal according to an embodiment of the present invention will be described. FIG. 1 is a side view (a) showing the structure of this crimp terminal 1 and a cross-sectional view (b) in the C-C direction thereof, corresponding to FIG. 5. This crimp terminal 1 also has a terminal connection portion 10 and an electric wire connection portion 20 integrated and made of a metal material, similar to the conventional crimp terminal 9. There is no difference in the terminal connection portion 10 from the above-mentioned crimp terminal 9. Also, the connection method of the wiring 100 (core wire 100A) thereto is the same. Here, in particular, the cross-sectional shape of the electric wire connection portion 20 (FIG. 1(b)) is different from that of the electric wire connection portion 90 (FIG. 5(b)).

[0019] As shown in FIG. 5(b), the above-mentioned electric wire connection portion 90 has a cylindrical shape, and since the wall thickness of the outer wall constituting this cylindrical shape is uniform in the circumferential direction, its cross-sectional shape is an annular shape. On the other hand, as shown in FIG. 1(b), in this electric wire connection portion 20, the outer peripheries of both ends in the y direction (horizontal direction) of the cross section of the above-mentioned annular shape are locally cut linearly along the z direction (vertical direction), and it is configured by so-called H-cut processing. In this case, the cut portions 20A, 20B that are cut are formed parallel to each other along the z direction, and become thin-walled portions 21A, 21B where both end sides along the y direction of the electric wire connection portion are locally thinned.

[0020] In this case, the cross-sectional shapes before and after caulking corresponding to FIG. 7 are shown in FIGS. 2(a) and 2(b). In this case, the upper die (first die) 210 and the lower die (second die) 220 are the same as those in FIG. 7. Therefore, in the form of FIG. 2(b) in which the wire connection portion 20 is deformed by the same process, burrs 22 are formed in the region D.

[0021] However, by the above-described H-cutting process, thin-walled portions 21A and 21B that are locally thinned are provided at portions where the burrs 22 are formed in the wire connection portion 20 (both end portions in the y direction). For this reason, the amount of the metal material constituting the burr 22 is reduced in this portion, and the burr 22 in FIG. 2(b) is shorter than the burr 91 in FIG. 7(b). Therefore, in the wire with terminals 300 manufactured in this way, as shown in FIG. 3 which is the top view corresponding to FIG. 8, even if the burr 22 is formed, the protruding amount along the y direction is small.

[0022] In the above example, the wire connection portion 20 in which the thin-walled portions 21A and 21B are formed on both end portions in the y direction due to the H-cutting process of the cylindrical shape is used. Generally, since the H-cutting process can be easily performed by partially cutting the surface of the cylindrical shape or the like, this wire connection portion 20 (crimp terminal 1) can be obtained easily and inexpensively.

[0023] On the other hand, as shown in FIG. 1(b), in this case, since a wide region on both end portions in the y direction of the wire connection portion 20 becomes thin, the mechanical strength of the entire wire connection portion 20 may be greatly reduced.

[0024] In contrast, FIG. 4 is a cross-sectional view of the wire connection portion 30 in which the thin-walled portions 31A and 31B are formed by forming the substantially arc-shaped cutout portions 30A and 30B on both end portions in the y direction instead of performing the H-cutting process. In this case, since a thinned region is provided only near the boundary between the upper die 210 and the lower die 220 in FIG. 2(a), the decrease in the overall mechanical strength of the wire connection portion 30 is reduced.

[0025] In FIG. 1, since the cut portions 20A and 20B are formed over the entire surface along the x-direction inside the wire connection portion 20, generation of burrs is particularly suppressed over the entire x-direction. However, as described above, burrs are particularly likely to occur outside the ends of the upper convex portion 212 and the lower convex portion 222 in the used mold. Therefore, such a thin-walled portion may be formed only at such locations. In this case, the wire connection portion is not thinned more than necessary, and the mechanical strength of the wire connection portion can be maintained high.

[0026] As described above, in the above example, the cross-sectional shape of the wire connection portion after caulking is as shown in FIG. 2(b). However, this cross-sectional shape is determined by the shapes of the inner surfaces of the upper mold (the first mold) and the lower mold (the second mold) to be used, and the shape is set as appropriate. In any shape, it is clear that burrs as described above become an obstacle in the wire with terminals. In this case, as long as the wire is fixed to the closed barrel type terminal by the caulking process combining the first mold and the second mold as described above, the above configuration is effective.

[0027] Also, when burrs become large only on one side in the y-direction of FIG. 8, for example, due to the machining accuracy of the first mold and the second mold, the thin-walled portion of the wire connection portion may be provided only on this side. That is, it is not essential to provide the thin-walled portion on both sides.

[0028] Also, as described above, actually, the terminal connection portion and the wire connection portion are integrally formed. Therefore, as a processing method for forming the thin-walled portion, for example, a method that can be easily performed after the terminal connection portion and the wire connection portion are integrally formed as described above can be appropriately used. This method is not limited to the methods shown in FIGS. 1(b) and 4.

[0029] The present invention has been described based on the embodiments. It is understood by those skilled in the art that these embodiments are examples, and various modifications are possible in the combination of each of these components, and such modifications are also within the scope of the present invention.

Explanation of Symbols

[0030] 1, 9 Crimp Terminals 10 Terminal Connection Part 20, 30, 90 Wire Connection Parts 20A, 20B Cut Parts 21A, 21B, 31A, 31B Thin Wall Parts 22, 91 Burrs 30A, 30B Notches 100 Wiring 100A Core Wire (Wire) 100B Coating Layer 210 Upper Mold (First Mold) 211 Upper Contact Part 212 Upper Mold Projection (First Projection) 213 Upper Mold Depression (First Depression) 220 Lower Mold (Second Mold) 221 Lower Contact Part 222 Lower Mold Projection (Second Projection) 223 Lower Mold Depression (Second Depression) 300 Wire with Terminal

Claims

1. A crimp terminal including a wire connection portion that is made of a metal material, houses a wire extending along a first direction in a substantially cylindrical internal space having a central axis along the first direction, and is deformed by being pressed along a second direction perpendicular to the first direction to fix the wire, wherein in a cross section perpendicular to the first direction, the wire connection portion includes a thin-walled portion in which the thickness of the metal material constituting the outer wall of the substantially cylindrical shape is locally thinned in the circumferential direction at an end along a third direction perpendicular to the second direction. The crimp terminal is characterized by this.

2. The crimp terminal according to claim 1, wherein the thin-walled portions are respectively formed at both ends along the third direction in the wire connection portion.

3. The crimp terminal according to claim 1 or 2, wherein in a cross section perpendicular to the first direction, the wire connection portion has a shape in which a region including an end along the third direction on the outer wall is removed along the second direction.

4. A wire with a terminal, characterized in that the wire is fixed to the wire connection portion of the crimp terminal according to claim 1 or 2.

5. A method for manufacturing a wire with a terminal, in which the wire is fixed to the crimp terminal according to claim 1 or 2, the method comprising: a fixing step of housing the wire in the internal space of the wire connection portion and bringing a first mold and a second mold into contact with and fixing them to the wire connection portion on one side and the other side along the second direction, respectively, which are on the side of the wire connection portion other than the thin-walled portion; a pressing step of pressing the first mold and the second mold from the state fixed in the fixing step to the other side and the one side in the second direction, respectively, to deform the wire connection portion and fix the wire connection portion and the wire; The method for manufacturing a wire with a terminal is characterized by including these steps.

6. The first mold includes a first convex portion that is located on one side in the third direction when viewed from the wire connection portion in the fixing step and protrudes toward the other side in the second direction; The second mold includes a second convex portion that is located on the other side in the third direction when viewed from the wire connection portion in the fixing step and protrudes toward the one side in the second direction. The manufacturing method of the wire with a terminal according to claim 5, characterized in that a first concave portion for guiding the second convex portion in the pressing step is provided in the first mold, and a second concave portion for guiding the first convex portion in the pressing step is provided in the second mold, respectively.

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