JP2009054549A - Electric wire with terminal, and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric wire with a terminal which can secure a mechanical strength and can prevent a deterioration of a contact resistance as well while the same has a simple terminal structure which is hard to cause a crack, and to provide a manufacturing method of the electric wire with a terminal in which a break off of an electric wire can be prevented during its manufacture. <P>SOLUTION: On a conductor barrel 16 of a terminal 10 composing an electric wire with a terminal, there are formed a first crimping portion 16a of a low crimping height, a second crimping portion 16b of a high crimping height, and a relay crimping portion 16c of which the crimping height changes continuously between both of the above crimping portions 61a, 16b. The conductor barrel 16 can be manufactured by using a metal die which has a first pressing surface to correspond with the first crimping portion 16a, a second pressing surface to correspond with the second crimping portion 16b, and a relay pressing surface to correspond with the relay crimping portion 16c. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a terminal-attached electric wire included in an automobile wire harness and the like and a method for manufacturing the electric wire.

  Conventionally, crimping is frequently used as a means for crimping a terminal to the end of an insulated wire. This crimping is performed by caulking a conductor barrel formed on the terminal in advance to the end of the conductor of the insulated wire using a mold.

  With this crimping technique, it is difficult to set the crimp height of the conductor barrel. On the other hand, if the crimping height is set small (ie, the crimping degree is set high), the contact resistance between the conductor barrel and the conductor of the electric wire is reduced, but the reduction rate of the conductor cross-sectional area is high. There is a disadvantage that the mechanical strength is lowered. On the contrary, when the crimping height is set large (that is, the crimping degree is set high), the mechanical resistance can be kept high, while the contact resistance between the conductor barrel and the conductor of the wire is increased. Inconvenience arises.

Therefore, Patent Document 1 discloses a technique for simultaneously forming a portion with a high crimping height and a portion with a small crimping height on the conductor barrel. The portion where the crimping height is large contributes to maintenance of mechanical strength, and the portion where the crimping height is small contributes to a decrease in contact resistance. These portions can be simultaneously formed by using a mold having a pressing surface with a step in the middle.
JP 59-165390 A

  In the electric wire with a terminal described in Patent Document 1, there is a discontinuous step between a portion with a high crimping height and a portion with a small crimping height of the terminal, and the terminal has a step with the step. Cracks are likely to occur.

  Further, it is difficult to form a portion with a large crimping height and a portion with a small crimping height as described in Patent Document 1 using a conventional terminal having only a single conductor barrel. In practice, it is necessary to separately form a barrel for forming a portion with a high crimping height and a barrel for forming a portion with a small crimping height. This complicates the terminal structure.

  Furthermore, at the manufacturing stage, there is a possibility that a large shearing force may act on the end of the conductor due to the step, and when the end of the conductor is broken by this shearing force, there is a disadvantage that the resistance is increased.

  In view of such circumstances, the present invention provides a terminal-attached electric wire capable of achieving both ensuring of mechanical strength and reduction in contact resistance while having a simple terminal structure that is difficult to crack, and at the time of manufacturing the same. It aims at providing the manufacturing method of the said electric wire with a terminal which can control the fracture of an electric wire.

  As means for solving the problems, the present invention provides an insulated wire having a conductor and an insulating coating covering the conductor, the terminal of the insulating coating is exposed by removing the terminal of the insulating coating, and the terminal of the insulated wire A terminal-attached electric wire having a terminal to be crimped to the terminal, the terminal having a conductor barrel to be crimped to a terminal of the conductor of the insulated wire, and the conductor barrel is a tip side portion of the terminal of the conductor A first crimping portion that is crimped to the second crimping portion, and a second crimping portion that is crimped to a portion on the rear side of the tip end portion of the end of the conductor and has a greater crimping height than the first crimping portion; A crimping height that is interposed between the first crimping part and the second crimping part and continuously increases from the crimping height of the first crimping part to the crimping height of the second crimping part as it goes rearward. The relay pressure-bonding portion is integrally provided.

  Moreover, this invention is a method for manufacturing the said electric wire with a terminal, Comprising: The terminal shaping | molding process which shape | molds the terminal which has a conductor barrel crimped | bonded to the terminal of the conductor of the said insulated wire as said terminal, The said conductor barrel A crimping step of crimping to the end of the conductor by caulking by pressing the mold, and in the crimping step, a first pressing surface and a second pressing higher than the first pressing surface are used as the mold. And a relay pressing surface that is interposed between the first pressing surface and the second pressing surface and continuously changes from the height of the first pressing surface to the height of the second pressing surface. Using a mold having a pressing surface, the terminal is pressed by the pressing surface in a state where the alignment direction of the first pressing surface, the relay pressing surface, and the second pressing surface is aligned with the axial direction of the terminal. By means of the conductor barrel, the end of the conductor A first pressure-bonding portion that is pressure-bonded to the end-side portion, and a second pressure-bonding portion that is pressure-bonded to a portion behind the tip-side portion of the end of the conductor and has a pressure-bonding height greater than that of the first pressure-bonding portion. Crimping portion that is interposed between the first crimping portion and the second crimping portion and continuously increases from the crimping height of the first crimping portion to the crimping height of the second crimping portion toward the rear. A relay crimping portion having a height is formed.

  In the electric wire with terminal, the coexistence of the first crimping portion and the second crimping portion having different crimping heights makes it possible to ensure both the mechanical strength and the contact resistance. In addition, the presence of a relay crimping portion that makes these continuous between the two crimping portions effectively prevents cracks from occurring between the first crimping portion and the second crimping portion. Further, since the conductor barrel is continuous from the first crimping portion to the second crimping portion, it is not necessary to form a barrel individually for each crimping portion.

  Moreover, according to the said manufacturing method, as a metal mold | die for manufacturing the said electric wire with a terminal, the 2nd for forming the 1st press surface for forming the said 1st crimping part, and the said 2nd crimping part. By using a die having a relay pressing surface between the pressing surfaces, a large shearing force is prevented from acting on the conductor between the pressing surfaces, and the conductor is cut due to the shearing force and the electric resistance thereby Can be prevented.

  In the terminal-attached electric wire, the upper surface of the end connected to the first crimping portion of the relay crimping portion is continuously inclined from the same inclination as that of the first crimping portion as the distance from the first crimping portion increases. It is more preferable to form a curved surface having an increasing inclination. Similarly, the upper surface of the end connected to the second crimping portion of the relay crimping portion has a slope that continuously decreases to the same slope as the second crimping portion toward the second crimping portion. It is more preferable to form a curved surface having Such a curved surface can effectively suppress the occurrence of cracks at the boundary between the relay crimping portion and the first crimping portion and at the boundary between the relay crimping portion and the second crimping portion. To.

  Moreover, in the said manufacturing method, as the said metal mold | die, it is equivalent to the inclination of the said 1st press surface as the edge part by the side connected to the said 1st press surface among the relay press surfaces leaves | separates from the said 1st press surface. It is more preferable to use a mold having an inclination that continuously increases from the inclination. Similarly, as the mold, the end of the relay pressing surface on the side connected to the second pressing surface is continuously inclined to the same inclination as the inclination of the second pressing surface toward the second pressing surface. It is more preferable to use a mold having a decreasing slope. The use of such a mold also makes it possible to alleviate stress concentration at the boundary portion between the relay crimping portion and the first crimping portion and at the boundary portion between the relay crimping portion and the second crimping portion.

  As described above, in the electric wire with terminal according to the present invention, both the first crimping portion and the second crimping portion can ensure both mechanical strength and lower contact resistance. There is an effect that the crack of the terminal can be effectively suppressed by interposing the relay crimping portion therebetween. Further, since the conductor barrel is continuous from the first crimping portion to the second crimping portion, it is not necessary to form a barrel individually for each crimping portion.

  Moreover, according to the manufacturing method of the electric wire with a terminal which concerns on this invention, as a metal mold | die for manufacturing the said electric wire with a terminal, the 1st press surface for forming the said 1st crimping part and the said 2nd crimping part are used. By using a die having a relay pressing surface between the second pressing surface for forming, it is possible to prevent a large shearing force from acting on the conductor between the two pressing surfaces and to prevent the conductor resulting from the shearing force. There exists an effect which can prevent a cutting | disconnection and the increase in electrical resistance by this.

  A preferred embodiment of the present invention will be described with reference to the drawings. In this embodiment, the terminal-attached electric wire is manufactured by the following terminal molding process and crimping process.

1) Terminal shaping | molding process In this process, the terminal 10 as shown in FIG.1 and FIG.2, ie, the terminal 10 before crimping | bonding to the terminal of an electric wire, is shape | molded. This molding is performed by punching a terminal plate from a metal plate and bending the terminal plate in the same manner as a normal terminal.

  The said terminal 10 has the electrical contact part 12 and the wire crimping | compression-bonding part 14 back and forth like the conventional terminal. In this embodiment, the electrical contact portion 12 is female and is formed in a box shape into which a male terminal (not shown) can be inserted. The wire crimping portion 14 includes a pair of left and right conductor barrels 16 and a pair of left and right insulation barrels 18. The two conductor barrels 16 have a U-shaped front shape as shown in FIG. 2, and the two insulation barrels 18 have the same shape.

  Therefore, the terminal-attached electric wire according to this embodiment can be manufactured using a terminal having the same shape as a conventional terminal as it is.

2) Crimping step In this step, the conductor barrel 16 and the insulation barrel 18 are caulked by a common mold, so that the wire crimping portion 14 including both barrels 16 and 18 becomes an electric wire 20 as shown in FIG. Crimped to the terminal. The electric wire 20 has a conductor 22 composed of a plurality of strands and an insulating coating 24 covering the conductor 22, and a terminal treatment for removing the terminal of the insulating coating 24 is performed to expose the terminal of the conductor 22. is doing.

  In this crimping process, a mold base 28 as shown in FIG. 2 and a mold 30 as shown in FIG. 1 are used. Then, the wire crimping portion 14 is set on the mold base 28, and the die 30 with respect to the wire crimping portion 14 in a state where the end of the wire 20 is set inside the wire crimping portion 14. , The conductor barrel 16 of the wire crimping portion 14 is caulked so as to embrace the conductor 22, and similarly, the insulation barrel 18 is caulked so as to embrace the insulating coating 24.

  The mold 30 includes a conductor-side mold 30A having a conductor-side pressing surface 32 for caulking the conductor barrel 16, and an insulating-side mold having an insulating-side pressing surface 34 for caulking the insulation barrel 18. 30B. The conductor-side pressing surface 32 is lower than the insulating-side pressing surface 34, so that a step is provided between the pressing surfaces 32, 34.

  As a feature of this manufacturing method, the conductor-side pressing surface 32 used for caulking the conductor barrel 16 includes a first pressing surface 35 as shown in FIGS. 1 and 3 and its rear side (that is, opposite to the tip of the electric wire 20). And a relay pressing surface 38 interposed between the two pressing surfaces 35, 36.

  The first pressing surface 35 and the second pressing surface 36 are both horizontal surfaces, but the first pressing surface 35 is lower than the second pressing surface 36. The relay pressing surface 38 is inclined between the pressing surfaces 35 and 36 so that the pressing surfaces 35 and 36 are continuous. Specifically, the relay pressing surface 38 according to this embodiment forms a flat surface having an inclination connecting the rear end of the first pressing surface 35 and the front end of the second pressing surface 36. That is, the relay pressing surface 38 has a height that continuously changes from the height of the first pressing surface 35 to the height of the second pressing surface 36.

  Note that the boundary portion between the relay pressing surface 38 and the first pressing surface 35 and the second pressing surface 36, that is, the front and rear end portions of the relay pressing surface 38 have shapes or corners whose inclination changes discontinuously. Although it may be a shape having a corner, it is more preferable that the portion is constituted by a smooth curved surface as shown in FIG. In other words, the end 38a of the relay pressing surface 38 that is connected to the first pressing surface 35 has an inclination equivalent to the inclination of the first pressing surface 35 as the distance from the first pressing surface 35 increases (in the drawing). It is preferable that the curved surface has a slope that continuously increases from (horizontal), and an end 38b of the relay pressing surface 38 that is connected to the second pressing surface 36 is connected to the second pressing surface 36. It is preferable that the curved surface has a shape having an inclination that continuously decreases to an inclination (horizontal in the figure) equivalent to the inclination of the second pressing surface 36 as it goes.

  Further, portions of the relay pressing surface 38 other than the end portions 38a and 38b are not limited to planes, and may be appropriate curved surfaces.

  Using the mold 30 and the mold table 28 as described above, a terminal-attached electric wire as shown in FIG. 5 is manufactured. Specifically, the terminal 10 is a mold in a posture in which the alignment direction of the first pressing surface 35, the relay pressing surface 38, the second pressing surface 36, and the insulating-side pressing surface 34 matches the axial direction of the terminal 10. In a state where the terminal of the electric wire 20 is set in the terminal 10 while being set on the table 28, the entire mold 30 is lowered toward the mold table 28, whereby the conductor of the mold 30 is The side mold 30A and the insulation mold 30B caulk the conductor barrels 16 and 18 of the terminal 10 to the conductor 22 and the insulation coating 24 of the electric wire 20, respectively.

  Specifically, the conductor barrel 16 of the terminal-attached electric wire has a first crimping portion 16a having an upper surface having a shape corresponding to the first pressing surface 35 and an upper surface having a shape corresponding to the second pressing surface 36. A second crimping portion 16b and a relay crimping portion 16c having an upper surface having a shape corresponding to the relay pressing surface 38 are formed. The first crimping portion 16a is a portion that is crimped to the tip end portion of the end of the conductor 20, and the second crimping portion 16b is crimped to a portion behind the tip end portion of the end of the conductor. And a portion having a greater crimping height than the first crimping portion 16a. The relay crimping portion 16c is interposed between the first crimping portion 16a and the second crimping portion 16b, and the crimping height of the second crimping portion 16b is increased from the crimping height of the first crimping portion 16a toward the rear. It has a crimping height that continuously increases to the height.

  In this terminal-attached electric wire, the first crimping portion 16a having a small crimping height contributes to a decrease in contact resistance, and the second crimping portion 16b having a large crimping height contributes to securing mechanical strength (particularly tensile strength). . In addition, the presence of a relay crimping portion 16c that continues the crimping portions 16a and 16b between the crimping portions 16a and 16b effectively suppresses the generation of cracks at the portion between the crimping portions 16a and 16b. To do. Further, since the entire conductor barrel 16 is continuous from the first crimping portion 16a to the second crimping portion 16b, it is not necessary to form a barrel individually for each crimping portion.

  In particular, when the conductor side mold 30A as shown in FIG. 4, that is, the mold 30 in which the front end 38a and the rear end 38b of the relay pressing surface 38 are configured with a smooth curved surface, A relay crimping portion 16 c having a more preferable shape is formed on the terminal 10 of the electric wire with terminal formed by the mold 30.

  Specifically, the upper surface of the end connected to the first crimping portion 16a in the relay crimping portion 16c is a curved surface corresponding to the shape of the front end 38a of the relay pressing surface 38, that is, the first crimping. As the distance from the portion 16a increases, a curved surface having an inclination that continuously increases from an inclination equivalent to the inclination of the first crimping portion 16a is formed. Similarly, the upper surface of the end connected to the second crimping portion 16b in the relay crimping portion 16c is a curved surface corresponding to the shape of the rear end 38b of the relay pressing surface 38, that is, the second crimping. As it goes to the part 16b, it is formed into a curved surface having an inclination that continuously decreases to an inclination equivalent to the inclination of the second crimping part 16b. These upper surface shapes make it possible to effectively suppress the occurrence of cracks at the boundary between the relay crimping portion 16c and the first and second crimping portions 16a and 16b.

  Further, when the electric wire with terminal is manufactured, unlike the case where a mold in which the first pressing surface 35 and the second pressing surface 36 are directly adjacent to each other is used as shown in FIG. The interposition of the relay pressing surface 38 between 35 and the second pressing surface 36 prevents a large shearing force from acting on the conductor between the pressing surfaces 35, 36. Thereby, the cutting | disconnection of the conductor resulting from the said shear force and the increase in electrical resistance by this are prevented. In particular, when the mold 30 is used in which the front end 38a and the rear end 38b of the relay pressing surface 38 have a smooth curved surface as shown in FIG. It is also possible to alleviate stress concentration at the boundary between the crimping part 16a and the second crimping part 16b.

  In the present invention, the size of the step between the first crimping part 16a and the second crimping part 16b and the inclination of the relay crimping part 16c can be set as appropriate. Further, the insulation barrel 18 may be omitted depending on the specification.

It is a partial cross section side view which shows the manufacturing process of the electric wire with a terminal which concerns on embodiment of this invention. It is a front view which shows the said manufacturing process. It is a perspective view which shows the cross-sectional shape of the conductor side metal mold | die used at the said manufacturing process. It is sectional drawing which shows the suitable example of the shape of the conductor side press surface in the said conductor side metal mold | die. It is a side view which shows the electric wire with a terminal manufactured through the said manufacturing process. It is sectional drawing which shows the comparative example of the said conductor side metal mold | die.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Terminal 12 Electrical contact part 14 Wire crimping part 16 Conductor barrel 16a 1st crimping part 16b 2nd crimping part 16c Relay crimping part 18 Insulation barrel 20 Electric wire 22 Conductor 24 Insulation coating 30 Mold 30A Conductor side mold 30B Insulation mold Mold 32 Conductor side pressing surface 34 Insulating side pressing surface 35 First pressing surface 36 Second pressing surface 38 Relay pressing surface 38a Front end of relay pressing surface 38b Rear end of relay pressing surface

Claims (6)

A terminal-equipped electric wire having a conductor and an insulating coating covering the conductor, and having an insulated wire from which the end of the insulating coating is removed to expose the end of the conductor, and a terminal to be crimped to the end of the insulated wire And
The terminal has a conductor barrel that is crimped to the end of the conductor of the insulated wire,
The conductor barrel is crimped to a first crimping portion that is crimped to the distal end portion of the end of the conductor, and is crimped to a portion behind the distal end portion of the end of the conductor, and from the first crimping portion. A second pressure-bonding portion having a large pressure-bonding height, and a second pressure-bonding portion that is interposed between the first pressure-bonding portion and the second pressure-bonding portion, and from the pressure-bonding height of the first pressure-bonding portion toward the rear. A terminal-attached electric wire integrally having a relay crimping portion having a crimping height that continuously increases to a crimping height of. In the electric wire with a terminal according to claim 1,
The upper surface of the end connected to the first pressure-bonding portion of the relay pressure-bonding portion has a curved surface having an inclination that continuously increases from the same inclination as the inclination of the first pressure-bonding portion as the distance from the first pressure-bonding portion increases. An electric wire with a terminal characterized by In the electric wire with a terminal according to claim 1 or 2,
The upper surface of the end connected to the second pressure-bonding portion of the relay pressure-bonding portion has a curved surface having an inclination that continuously decreases to the same inclination as the inclination of the second pressure-bonding portion toward the second pressure-bonding portion. An electric wire with a terminal characterized by Manufacturing an electric wire with a terminal having a conductor and an insulating coating covering the conductor, and having an insulated wire from which the end of the insulating coating is removed to expose the end of the conductor, and a terminal to be crimped to the terminal of the insulated wire A method for
As the terminal, a terminal molding step of molding a terminal having a conductor barrel to be crimped to the terminal of the conductor of the insulated wire,
A crimping step of crimping the conductor barrel by crimping the conductor barrel by pressing a die,
In the crimping step, the mold is interposed between a first pressing surface, a second pressing surface higher than the first pressing surface, the first pressing surface and the second pressing surface, Using a mold having a pressing surface that is continuous with a relay pressing surface that continuously changes from the height of one pressing surface to the height of the second pressing surface, the first pressing surface, the relay pressing surface, and the first 2 The first crimping portion that is crimped to the conductor barrel by pressing the terminal with the pressing surface in a state where the alignment direction of the pressing surface and the axial direction of the terminal are aligned. A second crimping portion that is crimped to a portion on the rear side of the end portion of the end of the conductor and has a greater crimping height than the first crimping portion; the first crimping portion; 2 between the crimping part and from the crimping height of the first crimping part toward the rear Serial manufacturing method of terminal-equipped electric wire and forming a relay crimping portion having a crimp height second continuously increases until crimp height of the crimp portion. In the manufacturing method of the electric wire with a terminal according to claim 4,
As the mold, the end of the relay pressing surface that is connected to the first pressing surface is continuously increased from an inclination equivalent to the inclination of the first pressing surface as it is separated from the first pressing surface. The manufacturing method of the electric wire with a terminal characterized by using the metal mold | die which has. In the manufacturing method of the electric wire with a terminal according to claim 4 or 5,
As the mold, the end of the relay pressing surface on the side connected to the second pressing surface continuously decreases to an inclination equivalent to the inclination of the second pressing surface toward the second pressing surface. The manufacturing method of the electric wire with a terminal characterized by using the metal mold | die which has.

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