JP2018133226A - Electric wire with terminal, and manufacturing method of electric wire with terminal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric wire with terminal capable of preventing a gap from being generated between distal ends of a pair of caulking pieces, while maintaining caulking forces by the pair of caulking pieces.SOLUTION: The present invention relates to an electric wire 1 with terminal in which a terminal 10 is connected to a covered conductor 2. A core wire crimp part (second barrel) 13 of the terminal 10 which is crimped to a core wire 21 of the covered conductor 2 comprises: a bottom 131 on which the core wire is mounted; and a pair of caulking pieces 132 which rise from an end of the bottom in a width direction and are bent to hold the core wire and in which inner peripheral surfaces 132α of distal ends 132D are brought into contact with each other. Each of the paired caulking pieces includes: a first curved part 132A which is curved in such a manner that a curvature center is positioned inside the core wire crimp part; and a second curved part 132B which is provided between the first curved part and the distal end and curved in such a manner that a curvature center is positioned outside the core wire crimp part, and satisfies the relationship of a curvature radius Rof the first curved part>a curvature radius Rof the second curved part>a curvature radius Rof a boundary between the bottom and the caulking piece.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an electric wire with a terminal and a method for manufacturing an electric wire with a terminal.

  As the electric wire with terminal, the core wire crimping portion of the terminal for crimping the core wire of the electric wire has a base portion and a pair of crimping pieces extending from both sides of the base portion, and a pair of additional wires are inserted so as to embrace the core wire. It is known that the fastening pieces are crimped to the core wire, and the tip portions of the crimping pieces are bitten between the strands of the core wire (for example, see Patent Document 1). In such an electric wire with a terminal, the tip part is bitten between the strands of the core wire, so that the spring back of the crimping piece is suppressed, and the crimping force (crimping force of the terminal against the core wire) by the crimping piece is maintained. Has been.

Japanese Patent Application Laid-Open No. 2015-97202

However, in the electric wire with a terminal described in Patent Document 1, there is a possibility that a gap is generated between the tip portions of the pair of caulking pieces.
And if a clearance gap arises between the front-end | tip parts of a pair of crimping piece, foreign materials, such as water, may invade into the inside of a core wire crimping part from the clearance gap. In this case, for example, in a terminal-attached electric wire in which a terminal made of copper or a copper alloy is connected to a covered electric wire having a core wire made of a wire made of aluminum or an aluminum alloy, galvanic corrosion is caused by water that has entered the core wire crimping portion. Could occur.

  The problem to be solved by the present invention is to prevent a gap from being generated between the tip portions of a pair of crimping pieces while maintaining the crimping force (crimping force of the terminal against the core wire) by the pair of crimping pieces. It is providing the electric wire with a terminal which can be performed, and its manufacturing method.

[1] A terminal-attached electric wire according to the present invention is a terminal-attached electric wire in which a terminal is connected to a covered electric wire, and the core wire is placed on the core wire crimping portion of the terminal crimped to the core wire of the covered electric wire. And a pair of caulking pieces that are bent so as to rise from the widthwise end of the bottom part and embrace the core wire and the inner peripheral surfaces of the front end parts contact each other, and the pair of caulking pieces, A first bending portion that is curved so that the center of curvature is located inside the core crimping portion, and the center of curvature is provided between the first bending portion and the tip portion, and is located outside the core crimping portion. Each of the second curved portions curved in this manner, and satisfies the following formula (1).
R _A > R _B > R _C (1)
Where R _A is the radius of curvature of the first curved portion, R _B is the radius of curvature of the second curved portion, and R _C is the radius of curvature of the boundary between the bottom and the crimping piece. is there.

[2] In the above invention, the tip portions may be in close contact with each other via a tin plating layer formed on the inner peripheral surface of the tip portion.

[3] In the above invention, the tip of the tip may be disposed closer to the bottom than the top of the first curved portion.

[4] A method for manufacturing a terminal-attached electric wire according to the present invention is a method for manufacturing a terminal-attached electric wire in which a core wire crimping portion of a terminal is crimped to a core wire of a covered electric wire, and a terminal having a core wire crimping portion and a core wire A covered electric wire having an exposed core wire exposed portion, a step of placing the core wire on a bottom portion of the core wire crimping portion, and a pair of additional wires extending from both ends in the width direction of the bottom portion using a first mold; A first bending step in which the fastening pieces are bent so as to embrace the core wire so that the inner peripheral surfaces of the respective distal end portions of the crimping pieces are brought closer to each other, and a second mold is used to The inner peripheral surfaces are brought into contact with each other, and the center of curvature is provided between the first curved portion, the first curved portion, and the distal end portion located inside the core crimping portion, and the center of curvature is the center of the core crimping portion. The core wire is formed with the second curved portion located on the outside. And a second bending step of crimping the wire crimp portion, the manufacturing method of the electric wire with terminal which satisfies the following formula (1).
R _A > R _B > R _C (1)
Where R _A is the radius of curvature of the second curved portion, R _B is the radius of curvature of the first curved portion, and R _C is the radius of curvature of the boundary between the bottom and the crimping piece. is there.

  According to the present invention, a terminal-attached electric wire that prevents a gap from being generated between the tips of a pair of crimping pieces while maintaining the crimping force (the crimping force of the terminal against the core wire) by the pair of crimping pieces. And a manufacturing method thereof.

FIG. 1 is an exploded perspective view showing an electric wire with a terminal in an embodiment of the present invention. FIG. 2 is a side view showing the electric wire with terminal in the embodiment of the present invention. FIG. 3 is a view (a cross-sectional view taken along the line III-III in FIG. 2) perpendicular to the longitudinal direction of the terminal at the position of the second barrel of the electric wire with terminal. 4A to 4C are cross-sectional views illustrating a method for manufacturing a terminal-attached electric wire according to an embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is an exploded perspective view showing an electric wire 1 with a terminal according to an embodiment, and FIG. 2 is a side view showing the electric wire 1 with a terminal. As shown in these drawings, the electric wire with terminal 1 includes a covered electric wire 2 and a terminal 10 connected (crimped) thereto. The covered electric wire 2 includes a core wire 21 and an insulating outer skin 22 that covers the core wire 21. A core wire exposed portion where the core wire 21 is exposed from the insulating sheath 22 is formed at the end of the covered electric wire 2.

  The core wire 21 is a bundle of a plurality of strands 211 made of aluminum or an aluminum alloy, and is, for example, a stranded wire in which a plurality of strands 211 are twisted together. The core wire 21 is lighter than a core wire made of a bundle of a plurality of strands made of copper or a copper alloy. The core wire 21 may be a single wire composed of one strand. Examples of the material constituting the insulating skin 22 include insulating materials such as synthetic resins.

The terminal 10 is attached to the end of the covered electric wire 2 and electrically connects the covered electric wire 2 and the connection target. Therefore, the terminal 10 is preferably made of a metal material having good electrical conductivity, and is made of a metal material different from aluminum or an aluminum alloy (for example, a metal plate made of copper, copper alloy, iron, or the like). . In addition, when a terminal is formed from a metal plate made of aluminum or an aluminum alloy, a strong oxide film is likely to be formed on the surface of the terminal, so that there is a possibility that the continuity with a connection target is lowered.
The terminal 10 of the present embodiment is made of copper having good conductivity, and a copper plate having a tin plating layer on the surface is used. Thereby, when the terminal 10 is connected to the covered electric wire 2 having the core wire 21 made of aluminum or an aluminum alloy, galvanic corrosion of the core wire 21 can be suppressed.

  In manufacturing the terminal 10, generally, a terminal plate is cut out by punching a metal plate, and then the terminal 10 is formed by bending the plate. At this time, even when a copper plate having a tin plating layer is used, copper is exposed at the end face (cut surface) of the terminal-shaped plate material cut out by punching. For this reason, even if the terminal surface is covered with the tin plating layer, copper is exposed at the terminal end surface of the terminal 10 formed of such a plate material.

  The terminal 10 has a long outer shape, and a connection portion 11 connected to a connection target is formed on one end side (Y-axis negative direction side in the figure), and the other end side (Y-axis positive direction side in the figure). ), The first and second barrels 12 and 13 connected to the covered electric wire 2 are formed. Further, the terminal 10 has an elongated bottom portion extending along the longitudinal direction of the terminal, and this bottom portion constitutes a bottom portion 111 in the connection portion 11 and bottom portions 121 and 131 in the first and second barrels 12 and 13, respectively. doing.

The connection part 11 has a rectangular cylindrical part and a leaf spring part 14 provided in the rectangular cylindrical part. Then, a mating terminal (not shown) to be connected is inserted into the rectangular cylindrical portion, and the leaf spring portion 14 is brought into contact (pressure contact) with the mating terminal, whereby the terminal 10 and the mating terminal (connecting target) Are electrically connected to each other.
In addition, the structure of the connection part 11, a shape, and the connection method with a connection other party terminal are not specifically limited.

  The first barrel 12 is an open barrel type insulation barrel, and is crimped to a portion (hereinafter referred to as a covered portion) in which the core wire 21 of the covered electric wire 2 is covered with an insulating outer sheath 22. The first barrel 12 includes a bottom 121 and a pair of caulking pieces 122 extending from both ends of the bottom 121 in the width direction. A covered portion of the covered electric wire 2 is placed on the bottom portion 121.

  In the terminal-attached electric wire 1, the pair of crimping pieces 122 are bent so as to rise from both ends in the width direction (X-axis direction in the figure) of the bottom 121, and the covered portion of the covered electric wire 2 disposed on the bottom 121 is used. The first barrel 12 is crimped and fixed to the covered portion of the covered electric wire 2 by being bent (clamped) following the covered portion so as to be held.

The second barrel 13 is an open barrel type wire barrel, and is crimped to a portion where the core wire 21 in the covered electric wire 2 is exposed from the insulating outer sheath 22 (hereinafter referred to as a core wire exposed portion). That is, the second barrel 13 functions as a core wire crimping portion.
The second barrel 13 includes a bottom 131 and a pair of caulking pieces 132 extending from both ends of the bottom 131 in the width direction. On the bottom 131, the core wire exposed portion (core wire 21) of the covered electric wire 2 is placed.

  In the terminal-attached electric wire 1, the pair of caulking pieces 132 are bent so as to rise from both ends in the width direction (X-axis direction in the drawing) of the bottom portion 131, and the core wire exposed portion of the covered electric wire 2 disposed on the bottom portion 131. The second barrel 13 is crimped and fixed to the core wire exposed portion (core wire 21) of the covered electric wire 2 by being bent (clamped) so as to embrace the (core wire 21).

  Further, as shown in FIG. 1, the inner peripheral surface of the second barrel 13 including the bottom portion 131 and the pair of caulking pieces 132 is excluded from the inner peripheral surface 132α of the tip portion 132D of the pair of caulking pieces 132, A plurality of concave serrations 133 are provided. The plurality of serrations 133 are formed on the entire inner peripheral surface of the second barrel 13 excluding the tip. For this reason, even when the second barrel 13 is crimped to the core wire 21 made of aluminum or an aluminum alloy, the oxide film on the surface of the core wire 21 is broken at the edge portion of the serration 133, and the core wire 21 and the terminal 10 are connected. Can be connected electrically. In addition, the formation area of the serration 133 on the inner peripheral surface of the second barrel 13 only needs to include a portion in contact with the core wire 21.

  FIG. 3 is a diagram (III-III sectional view of FIG. 2) showing a cross section (hereinafter simply referred to as a cross section) orthogonal to the longitudinal direction of the terminal 10 at the position of the second barrel 13 of the electric wire 1 with a terminal. is there. As shown in this figure, the second barrel 13 has a symmetrical cross-sectional shape, and the pair of caulking pieces 132 are configured symmetrically. Note that the X-axis direction in the figure is the horizontal direction or the width direction, and the Z-axis direction in the figure is the vertical direction.

In the second barrel 13 crimped to the core wire 21, the bottom 131 is curved so as to swell downward. The curvature radius of the bottom 131 is larger than the curvature radii R _A and R _{B of a} first curved portion 132A and a second curved portion 132B described later.

The pair of caulking pieces 132 extending from both ends in the width direction of the bottom portion 131 are bent so as to rise from both ends in the width direction of the bottom portion 131. That is, the second barrel 13 is bent at a boundary portion 132 </ b> C between the end portion in the width direction of the bottom portion 131 and the lower end portion of the crimping piece 132. The center of curvature of the boundary portion 132C is located inside the second barrel 13, and the curvature radius _RC of the boundary portion 132C is the curvature radius of the first curved portion 132A and the second curved portion 132B described later. It is smaller than R _A and R _B.

  Further, the pair of caulking pieces 132 are bent so as to include a first bending portion 132A and a second bending portion 132B, respectively. The second bending portion 132B is provided in the vicinity of the distal end portion 132D of the crimping piece 132, and the first bending portion 132A is provided between the boundary portion 132C and the second bending portion 132B.

The center of curvature CA of the first curved portion 132 </ b> _A is located inside the second barrel 13. That is, the pair of caulking pieces 132 extending so as to rise from both ends (boundary portions 132C) in the width direction of the bottom portion 131 are curved toward the center in the left-right direction of the second barrel 13 in the first bending portion 132A. .

Center of curvature _{C B} of the second curved portion 132B is located outside of the second barrel 13. That is, the pair of caulking pieces 132 extending from the first curved portion 132A toward the center in the left-right direction of the second barrel 13 are directed toward the core wire 21 so as to bite the second curved portion 132B into the core wire 21. Curved downward.
The pair of caulking pieces 132 bent downward at the second bending portion 132B extend upward from the second bending portion 132B, and the tip end portion 132D is disposed at a position away from the core wire 21.

As described above, in the second barrel 13, the first curved portion 132A is curved so as to bulge outward from the second barrel 13, whereas the second curved portion 132B has the second curved portion 132B. It is curved so as to swell inside the barrel 13 (opposite to the first curved portion 132A).
The second bending portion 132B is positioned below the first bending portion 132A. Further, the distal end portion 132D is positioned above the second curved portion 132B (a position away from the core wire 21) without being bitten between the strands of the core wire 21.

In the present embodiment, the end portion 132D does not bite into the core wire 21 and the end surface (copper exposed surface) of the tip portion 132D is arranged away from the core wire 21, so the end surface (copper exposed surface) of the terminal 10 and the core wire The contact area with 21 is small.
The tip portions 132D are in contact with each other with the inner peripheral surfaces 132α facing each other. Here, since the terminal 10 is formed of a copper plate having a tin plating layer on the surface, the tip portions 132D of the pair of crimping pieces 132 are in close contact with each other via the tin plating layer.

Further, in the present embodiment, the position of the tip of the tip 132D of the pair of caulking pieces 132 is disposed closer to the bottom 131 than the highest position (top) of the first curved portion 132A. . That is, the tip of the tip 132D is made lower than the height of the top of the first curved portion 132A.
Thereby, in the electric wire with terminal 1, the tip portion 132D is prevented from interfering with surrounding components. For example, when the terminal 10 of the electric wire with terminal 1 is inserted into the terminal insertion hole of the connector, the tip portion 132D protrudes. It is possible to prevent the insertion of the terminal 10 into the terminal insertion hole from being hindered.

Further, in this embodiment, in the second barrel 13 which is crimped to the core wire 21, and the radius of curvature _{R A} of the first bending portion 132A, and the radius of curvature _{R B} of the second bending section 132B, the curvature of the boundary 132C The radius _RC satisfies the relationship of the following formula (1).
R _A > R _B > R _C (1)

In particular, the radius of curvature _{R C} of the boundary portion 132C is adapted remarkably small compared with the radius of curvature _{R B} of the curvature radius _{R A} of the first bending portion 132A the second bending section 132B, the boundary portion 132C Plastic deformation has occurred. As a result, the crimping piece 132 is less likely to spring back (elastic return) with the boundary portion 132C as a fulcrum, and the pair of crimping pieces 132 are separated from each other (in the direction of arrow C in the figure). It is difficult to displace.

On the other hand, the radius of curvature R _A of the first curved portion 132A is significantly larger than the radius of curvature R _C of the boundary portion 132C, and elastic deformation occurs in the first curved portion 132A. As a result, an elastic restoring force is generated in the caulking piece 132 with the center of the first bending portion 132A as a fulcrum.
This elastic restoring force is a force that rotates the tip side of the first bending portion 132A in the direction of pushing up from the bottom to the top. For this reason, the pair of caulking pieces 132 are urged in the direction in which the distal end portion 132D is separated from the core wire 21 (arrow A direction in the figure) while the distal end portions 132D are pressed against each other. If the tip 132D moves away from the core wire 21 due to this elastic restoring force, the crimping force by the crimping piece 132 (the crimping force of the second barrel 13 against the core wire 21) is reduced.

The radius of curvature _{R B} of the second bending section 132B is larger than the radius of curvature _{R C} of the boundary portion 132C, and is smaller compared to the radius of curvature _{R A} of the first bending portion 132A, the second The curved portion 132B is also elastically deformed. As a result, the caulking piece 132 has an elastic restoring force with the center of the second bending portion 132B as a fulcrum.
This elastic restoring force is a force that rotates the tip side of the second bending portion 132B in a direction of pushing down from the top to the bottom. For this reason, the pair of caulking pieces 132 are urged in a direction (arrow B direction in the figure) that suppresses the distal end portion 132D from separating from the core wire 21 while the distal end portions 132D are pressed against each other. Thereby, it can prevent that the crimping force by the crimping piece 132 falls by the elastic return force of the 1st curved part 132A, and the crimping force by the crimping piece 132 (crimping of the 2nd barrel 13 with respect to the core wire 21) Power) can be maintained.

  In the second barrel 13 shown in FIG. 3, the direction of the elastic return force generated at the first bending portion 132A of the caulking piece 132 on the left side in the drawing is the counterclockwise direction in the drawing, and the second bending portion The direction of the elastic restoring force generated at 132B is the clockwise direction in the figure. Further, the direction of the elastic return force generated at the first bending portion 132A of the caulking piece 132 on the right side in the drawing is the clockwise direction in the drawing, and the direction of the elastic return force generated at the second bending portion 132B is opposite to the drawing in the drawing. Clockwise direction.

In the present embodiment, during a first bending portion 132A and the distal end portion 132D, by providing the second bending section 132B of the center of curvature C _B is curved so as to be positioned in the barrel outside, the tip core of the unit The spring bag of the pair of caulking pieces 132 can be suppressed and the caulking force by the caulking pieces 132 (crimping force of the second barrel 13 against the core wire 21) can be maintained without biting between the lines. .

Further, due to the synergistic effect of the elastic return force of the first bending portion 132A and the elastic return force of the second bending portion 132B, the distal end portions 132D of the crimping pieces 132 are pressed against each other (the contact pressure between the distal end portions can be increased). ), The tip portions 132D can be brought into close contact with each other. Thereby, it can prevent that a clearance gap produces between tip part 132D of the crimping piece 132, and can prevent that foreign materials, such as water, penetrate | invade into the inside of the 2nd barrel 13 from between tip parts 132D.
Here, if the elastic restoring force generated in the second curved portion 132B in the direction of the arrow B in the drawing is too large, the tip portions 132D may be separated from each other and a gap may be generated between the tip portions. Therefore, the radius of curvature R _B of the second bending section 132B, is smaller than the radius of curvature of the first curved portion 132A.

In the present embodiment, the tip portions 132D are in contact with each other with a large contact pressure due to the synergistic effect of the elastic return force of the first bending portion 132A and the elastic return force of the second bending portion 132B. Thereby, the inner peripheral surfaces 132α of the tip end portion 132D are firmly adhered to each other through the tin plating layer.
Further, since the end portions 132D of the pair of caulking pieces 132 are arranged so that the end surfaces of the end portions 132D are away from the core wire 21 without being bitten between the strands of the core wire 21, they are made of aluminum or an aluminum alloy. The contact area between the core wire 21 and the end face (copper) of the terminal 10 is small.

  4A to 4C are cross-sectional views for explaining a method for manufacturing the terminal-attached electric wire 1 according to the present embodiment, particularly a method for crimping the second barrel 13 of the terminal 10 to the core wire 21 of the covered electric wire 2. FIG. As shown in these drawings, the process of crimping the second barrel 13 to the core wire 21 includes the first bending process using the first mold 5 and the second process using the second mold 6. Bending process.

First, as shown in FIG. 4A, the core wire 21 of the covered electric wire 2 is placed on the bottom 131 of the second barrel 13 in a state in which the pair of caulking pieces 132 are open to each other.
Next, as shown in FIG. 4B, a first bending process is performed. In this first bending step, the first mold 5 is used to curve a pair of caulking pieces 132 extending from both ends in the width direction of the bottom portion 131 so as to embrace the core wire 21, and The second barrel 13 is bent so that the inner peripheral surfaces 132α of the distal end portion 132D are close to each other. The first mold 5 includes an upper mold 51 and a lower mold 52.

  The upper die 51 is formed with a U-shaped main groove 51A that opens downward. A sub-groove 51B is formed in the center of the upper end of the main groove 51A. The sub-groove 51B includes arc-shaped groove walls on both the left and right sides, and gradually increases in width from the upper side to the lower side. On the other hand, the width of the lower mold 52 is set so as to be fitted to the main groove 51 </ b> A of the upper mold 51. An arcuate groove 52A is formed on the upper surface of the lower mold 52.

In the first bending step, the second barrel 13 on which the core wire 21 is placed on the bottom 131 is placed in the groove 52A of the lower die 52, and the core wire 21 and the second barrel 13 are placed on the upper die 51. The second barrel 13 is bent by being pressed (sandwiched) between the upper mold 51 and the lower mold 52 in a state of being accommodated in the main groove 51A. At this time, the second barrel 13 is bent at a boundary portion 132 </ b> C between the bottom portion 131 and the crimping piece 132. Further, the end portions 132D of the pair of caulking pieces 132 are guided into the sub-groove 51B and approach each other.
In addition, in order to make it easy to guide the front end portion 132D into the sub-groove 51B, it is preferable that the front end portion of the front end portion 132D is inclined (pointed).

  Next, as shown in FIG. 4C, a second bending process is performed. In the second bending step, the second barrel 13 is crimped using the second mold 6. The second mold 6 includes an upper mold 61 and a lower mold 62.

  The upper die 61 is formed with a main groove 61A that opens downward. The main groove 61A is configured symmetrically, and a sub-groove 61B is formed at the center of the upper end. The sub-groove 61B has groove walls on both the left and right sides, and gradually increases in width from the upper side to the lower side. In addition, a pair of convex portions 61C are formed at the center of the upper end of the main groove 61A. The pair of convex portions 61C is formed at the opening edge portion of the sub-groove 61B and protrudes downward from the upper end of the main groove 61A. On the other hand, the width of the lower mold 62 is set so as to be fitted to the main groove 61A of the upper mold 61. On the upper surface of the lower mold 62, an arc-shaped groove 62A is formed.

  In the second bending step, the second barrel 13 processed in the first bending step is placed in the groove 62A of the lower die 62, and the core wire 21 and the second barrel 13 are connected to the main groove 61A of the upper die 61. The second barrel 13 is crimped by pressurizing (squeezing) the upper die 61 and the lower die 62 in the state of being housed. At this time, the convex portion 61 </ b> C pushes down the distal end side of the crimping piece 132. By the above, the 2nd barrel 13 is crimped | bonded to the core wire 21 so that the 1st bending part 132A and the 2nd bending part 132B may be formed in the crimping piece 132, and the electric wire 1 with a terminal of this embodiment. Can be manufactured.

The configuration of the upper mold 61 of the second mold 6 (the shape and position of the main groove 61A, the sub-groove 61B, the convex portion 61C, etc.) is the same as that of the second barrel 13 that is crimped to the core wire 21. and the radius of curvature _{R a} of the curved portion 132A, and the radius of curvature _{R B} of the second bending section 132B, and the radius of curvature _{R C} of the boundary portion 132C is designed to satisfy the following relationship (1).
R _A > R _B > R _C (1)

In addition, “the electric wire with terminal 1” in the present embodiment corresponds to an example of “the electric wire with terminal” in the present invention, “covered electric wire 2” in the present embodiment corresponds to an example of “the covered electric wire” in the present invention, The “core wire 21” in the present embodiment corresponds to an example of the “core wire” in the present invention, the “terminal 10” in the present embodiment corresponds to an example of the “terminal” in the present invention, and the “second wire” in the present embodiment. The “barrel 13” corresponds to an example of the “core wire crimping portion” in the present invention.
Further, the “bottom part 131” in the present embodiment corresponds to an example of the “bottom part” in the present invention, and the “crimping piece 132” in the present embodiment corresponds to an example of the “crimping piece” in the present invention. The “boundary portion 132C” in the embodiment corresponds to an example of the “boundary portion” in the present invention, the “first curved portion 132A” in the present embodiment corresponds to an example of the “first curved portion” in the present invention, The “second curved portion 132B” in the present embodiment corresponds to an example of the “second curved portion” in the present invention, and the “tip portion 132D” in the present embodiment corresponds to an example of the “tip portion” in the present invention. To do.

  The embodiment described above is described for facilitating the understanding of the present invention, and is not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

  For example, in the above-described embodiment, the bottom 131 of the second barrel 13 is curved, but the bottom 131 may be flat. In addition, it is not essential to form a coating layer made of tin plating on the entire second barrel 13, and it is sufficient to form it on at least the inner peripheral surfaces (surfaces that contact each other) 132α of the pair of tip portions 132D.

DESCRIPTION OF SYMBOLS 1 ... Electric wire with a terminal 2 ... Covered electric wire 21 ... Core wire 211 ... Elementary wire 22 ... Insulation outer skin 10 ... Terminal 11 ... Connection part 111 ... Bottom part 12 ... 1st barrel 121 ... Bottom part 122 ... Clamping piece 13 ... 2nd barrel 131 ... bottom 132 ... caulking piece 132A ... first curved part 132B ... second curved part 132C ... boundary part 132D ... tip part 133 ... serration 5 ... first mold 51 ... upper mold 51A ... main groove 51B ... Sub-groove 52 ... Lower mold 52A ... Groove 6 ... Second mold 61 ... Upper mold 61A ... Main groove 61B ... Sub-groove 61C ... Projection 62 ... Lower mold 62A ... Groove C _A ... Center of curvature C _B ... Center of curvature R _A ... radius of curvature R _B ... radius of curvature R _C ... radius of curvature

Claims (4)

A terminal-attached electric wire with a terminal connected to a covered electric wire,
The core wire crimping portion of the terminal to be crimped to the core wire of the covered electric wire is bent so as to rise from the widthwise end portion of the bottom portion and to embrace the core wire. A pair of caulking pieces whose peripheral surfaces are in contact with each other;
The pair of caulking pieces is
A first bending portion that curves so that the center of curvature is located inside the core wire crimping portion;
A second bending portion that is provided between the first bending portion and the distal end portion and is bent so that the center of curvature is located outside the core crimping portion;
An electric wire with terminal that satisfies the following formula (1)
R _A > R _B > R _C (1)
Where R _A is the radius of curvature of the first curved portion, R _B is the radius of curvature of the second curved portion, and R _C is the radius of curvature of the boundary between the bottom and the crimping piece. is there. It is an electric wire with a terminal according to claim 1,
The said front-end | tip parts are the electric wires with a terminal which are mutually adhere | attached through the tin plating layer formed in the internal peripheral surface of the said front-end | tip part. It is an electric wire with a terminal according to claim 1 or 2,
A terminal-attached electric wire in which a tip of the tip is disposed closer to the bottom than a top of the first curved portion. In the method of manufacturing the terminal-attached electric wire in which the core wire crimping portion of the terminal is crimped to the core wire of the covered electric wire,
Preparing a covered electric wire having a core wire exposed portion where the core wire is exposed, and a terminal having a core wire crimping portion, and placing the core wire on the bottom of the core wire crimping portion;
Using a first mold, a pair of caulking pieces extending from both ends in the width direction of the bottom portion are bent so as to embrace the core wire, and the inner peripheral surfaces of the respective distal end portions of the caulking pieces are brought close to each other. 1 bending process;
Using the second mold, the inner peripheral surfaces of the tip portions are brought into contact with each other, and the first bending portion, the first bending portion, and the tip end having a center of curvature located inside the core wire crimping portion. A second bending step of crimping the core crimping portion to the core wire so as to form a second curved portion provided between the portions and having a center of curvature positioned outside the core crimping portion,
The manufacturing method of the electric wire with a terminal which satisfy | fills following (1) Formula.
R _A > R _B > R _C (1)
Where R _A is the radius of curvature of the second curved portion, R _B is the radius of curvature of the first curved portion, and R _C is the radius of curvature of the boundary between the bottom and the crimping piece. is there.

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