JP5874448B2 - Manufacturing method of electric wire with terminal - Google Patents

Description

The present invention relates to a method for producing a terminal with electric wire.

  As an electric wire with a terminal mounted on a vehicle such as an automobile, for example, a configuration in which a crimping piece of a terminal is crimped to a core wire that is exposed by peeling off an insulating coating at an end portion of the electric wire is known.

  In recent years, demand for so-called aluminum electric wires in which a core wire made of aluminum or an aluminum alloy is covered with an insulating coating is increasing from the viewpoint of weight reduction of the vehicle. Generally, a terminal made of copper or a copper alloy is used as a terminal connected to the aluminum electric wire.

  In such a configuration, since the core wire and the terminal of the electric wire are made of different metals, the connection portion between the core wire and the terminal has a slight amount of moisture and salt depending on the usage environment of the vehicle such as high temperature and humidity exposed to sea breezes. If it penetrates, there is a possibility that electrolytic corrosion will occur between the core wire and the terminal. Therefore, conventionally, measures for preventing electrolytic corrosion have been studied (for example, see Patent Document 1).

JP 2011-210593A

  In Patent Document 1, a solder seal in which an electric wire connecting portion is crimped in a state where an exposed core wire is sealed with solder, and a portion covered with an insulating coating of the electric wire and the solder seal are connected in a sealed state. It has been proposed to have a configuration including a seal connecting portion. However, such a configuration has a problem that the manufacturing cost is high.

  This invention is completed based on the above situations, Comprising: It aims at providing the electric wire with a terminal which can prevent an electric corrosion, suppressing its manufacturing cost, and its manufacturing method.

Further, the present invention provides an electric wire in which a core wire formed by twisting a plurality of strands made of aluminum or aluminum alloy is covered with an insulating coating, and an exposure exposed by peeling off the insulating coating at the end of the electric wire. A terminal having a crimping piece to be crimped to a core wire, and a method of manufacturing an electric wire with a terminal, which is made of copper or a copper alloy , and has an ionization tendency on a surface of a metal between copper and aluminum. After performing a pressing step of forming the crimping piece by pressing a metal base material on which a plating layer is formed, a coating forming step of forming an insulating coating made of an insulating material on the end face of the crimping piece run, after the crimping pieces formed by performing the press process was performed a crimping step of crimping the exposed core of the wire, the wire is placed in the crimping piece In a surface opposite to the electric wire mounting surface is, in the portion where the plating layer is peeled off in the bonding step, the manufacturing method of the electric wire with terminal performing a second film forming step of forming an insulating film made of an insulating material is there.

  The crimping piece of the terminal is formed, for example, by pressing a metal base made of copper or copper alloy into a predetermined shape. Therefore, regardless of whether or not the metal substrate is plated, copper or a copper alloy, which is a metal material constituting the metal substrate, is exposed at the end face of the pressed piece after pressing. If copper or copper alloy is exposed on the end face of the crimping piece, the salty water intrudes into it, causing the copper to act like an electrode due to the potential difference from the aluminum contained in the strands and corrode. There is a concern that the reaction is promoted and aluminum is eluted rapidly from the wire.

However, in the present invention, since an insulating film made of an insulating material is formed on the end face of the crimping piece, copper or a copper alloy is not exposed on the end face of the crimping piece. As a result, according to the present invention, since electric corrosion can be prevented only by forming an insulating film on at least the end face of the crimping piece, an electric wire with a terminal capable of preventing electric corrosion while suppressing manufacturing cost and A manufacturing method thereof can be provided.
In addition, since the surface of the metal substrate is plated with a metal that has an ionization tendency that is closer to that of the metal material (aluminum) than copper, the difference in ionization tendency between the surface of the metal substrate and the core wire ( (Potential difference) is reduced, which makes it difficult for electrolytic corrosion to occur, and suppresses the speed of electrolytic corrosion. As a result, according to the above configuration, electrolytic corrosion can be reliably prevented.
In addition, even when a terminal made of a metal base material on which a plating layer is formed is used, the plating layer peels off due to the contact between the crimping fitting and the metal base material in the operation of crimping the crimping piece to the exposed core wire. There is a case. In such a portion where the plating layer is peeled off, copper (alloy) constituting the metal base material is exposed, and there is a concern about the occurrence of electrolytic corrosion. Therefore, with the above configuration, since the copper (alloy) is not exposed even at the portion where the plating layer is peeled off, electrolytic corrosion can be prevented.

The plating layer may be a plating layer containing tin.
Such a configuration is suitable for prevention of electrolytic corrosion because the pinholes are few and a dense and uniform film is obtained, and it is possible to secure a predetermined electric conductivity or more. Furthermore, since the difference in ionization tendency between tin and aluminum is small, even if electrolytic corrosion occurs, the speed is suppressed.

The insulating coating may be composed of an insulating material selected from alumite, silica, copper oxide and copper sulfide.
With such a configuration, since the insulating coating is made of a material having high electrical insulation, a high electric corrosion prevention effect can be obtained.

  ADVANTAGE OF THE INVENTION According to this invention, the electric wire with a terminal which can prevent an electric corrosion, suppressing manufacturing cost, and its manufacturing method can be provided.

The side view of the electric wire with a terminal of Embodiment 1 Plan view of electric wire with terminal Partial plan view of chain terminal Partial plan view showing the state immediately before the exposed core wire is crimped by the crimping piece. Partial sectional view schematically showing the cross section of the terminal Partial rear view of chain terminal The fragmentary top view which shows the state just before crimping an exposed core wire with a crimping piece in the process of manufacturing the electric wire with a terminal of Embodiment 2. The partial back view of the chain terminal for creating the electric wire with a terminal explained in other embodiments (2)

<Embodiment 1>
The electric wire 10 with a terminal of Embodiment 1 which actualized this invention is demonstrated with reference to FIG. In the following description, the left side in FIGS. 1 and 2 is the front and the right side is the rear. Moreover, let the upper side in FIG. 1 and FIG. 5 be upper, and let the lower side be lower.

  As shown in FIGS. 1 and 2, the terminal-attached electric wire 10 of the present embodiment has a core wire crimping piece 25 (an example of a “crimping piece”) that is crimped to the wire 40 and the exposed core wire 41 exposed at the end of the wire 40. And a terminal 11 having. The terminal 11 is comprised from the metal base material 1 which forms the plating layer 3 on both surfaces of the metal plate made from copper or a copper alloy. The terminal 11 is formed into a shape as shown in FIG. 1 by bending the terminal piece 11A having a developed shape as shown in FIG.

  The plating layer 3 formed on the metal substrate is a plating layer 3 containing a metal whose ionization tendency is between copper and aluminum. Specifically, a plating layer 3 containing a metal such as nickel or tin can be mentioned. As the plating layer 3, a plating layer 3 containing tin (for example, a tin plating layer) is preferable. The tin plating layer has few pinholes and a dense and uniform film is obtained, so it is suitable for the prevention of electrolytic corrosion. In addition to ensuring a predetermined electrical conductivity, tin and aluminum differ in ionization tendency. Therefore, even if electrolytic corrosion occurs, the speed is suppressed, which is preferable.

  In the present embodiment, the terminal 11 includes a main body portion 12 having a substantially box shape that opens front and rear, and a male terminal tab (not shown) as a mating member is inserted into the main body portion 12 from the front. It is possible. On the rear side of the main body portion 12 of the terminal 11, a wire connecting portion 23 for placing and connecting the wire 40 is provided (details will be described later).

  The main body 12 of the terminal 11 is formed in a rectangular tube shape by bending a developed terminal piece 11A shown in FIG. 3 along the folding line L1. The main body 12 includes a bottom wall 13 extending forward and backward, a pair of side walls 14 and 15 raised from both side edges of the bottom wall 13, a ceiling wall 16 that continues from the side wall 14 and faces the bottom wall 13, and a side wall 15. And an outer wall 17 that overlaps the outside of the ceiling wall 16. A support piece 18 projecting toward the side wall 15 is provided at the side edge of the ceiling wall 16, and the support piece 18 is inserted into an insertion groove 19 formed in a cutout in the outer wall 17 and at the side of the insertion groove 19. By contacting the edge (the upper end surface of the side wall 15), the ceiling wall 16 can be supported in a posture substantially parallel to the bottom wall 13.

  An elastic contact piece 20 that can elastically contact the tab is provided from the front end of the bottom wall 13. Although details of the structure of the elastic contact piece 20 are not shown, after the tongue piece 20A that extends straight forward from the bottom wall 13 in the unfolded state shown in FIG. The main body 12 is formed by folding forward at a substantially central position in the length direction.

  A portion between the front and rear folded portions of the elastic contact piece 20 is a tab contact portion 20a that is opposed to the ceiling wall 16 and can be directly contacted with the tab. The portion protruding to the bottom is a support portion 20b that can come into contact with the bottom wall 13, and the tip portion 20c is bent upward in FIG.

  The elastic contact piece 20 can hold the tab inserted into the main body 12 in a state of being pinched between the ceiling wall 16 and the tab contact portion 20a, and is elastically deformed by being pressed by the tab. At this time, the elastic contact piece 20 is excessively bent by the support portion 20b being in contact with the bottom wall 13 and the tip portion 20c of the support portion 20b being in contact with the back side of the tab contact portion 20a. Can be regulated.

  The elastic contact piece 20 is formed to be narrower than the bottom wall 13. A locking hole 21 is formed in the bottom wall 13 so that when the terminal 11 is accommodated in a cavity of a housing (not shown), a lance provided in the cavity enters and can be locked. . A pair of stabilizers 22 functioning as guides for the insertion operation into the cavities and the like protrude from both side edges of the locking holes 21 (lower ends of the side walls 14 and 15).

  The wire connecting portion 23 of the terminal 11 is provided to extend rearward from the rear end of the bottom wall 13 of the main body portion 12. In the electric wire connection portion 23, two sets of crimping pieces 24 and 25 are provided at intervals from each other so as to extend from the bottom wall 13 of the main body portion 12 and extend in the width direction of the bottom wall 13. These two sets of crimping pieces 24 and 25 are formed so as to project symmetrically in the width direction.

  The electric wire 40 disposed in the electric wire connecting portion 23 is obtained by coating a core wire 41 formed by twisting metal wires 42 made of aluminum or aluminum alloy with an insulating coating 43 made of an insulating material. The terminal of the electric wire 40 is in a state where the insulation coating 43 is peeled off and the core wire 41 is exposed. The electric wire 40 is connected to the terminal 11 with the end of the exposed core wire 41 facing the main body 12 side.

  Of the two sets of crimping pieces 24, 25 of the electric wire connecting portion 23, the crimping piece 25 on the front side (main body 12 side) is a core wire crimping piece 25 that crimps the exposed core wire 41 and connects it to the terminal (an example of the crimping piece). The crimping piece 24 on the rear side (rear end side) is formed as an insulation coating crimping piece 24 that crimps a portion covered with the insulation coating 43 of the electric wire 40 and connects it to the terminal 11.

  An oxide film formed around the core wire 41 when the electric wire 40 is crimped on the surface 23A (the electric wire placement surface 23A, the surface arranged on the upper side in FIG. 1) on which the electric wire 40 of the core wire crimping piece 25 is arranged. A plurality of recesses 28 are provided for breaking (see FIGS. 3 and 4). The region 25 </ b> B where the plurality of recesses 28 are provided is a connection region 25 </ b> B where the electric wire 40 and the core wire crimping piece 25 are electrically connected.

  The hole edges of the recesses 28 have a parallelogram shape when viewed from the direction penetrating the paper surface of FIG. The plurality of recesses 28 are arranged at intervals in the direction in which the core wire 41 extends in a state in which the core wire crimping piece 25 is crimped to the core wire 41 and at intervals in the direction intersecting the direction in which the core wire 41 extends. (See FIG. 4).

  In the present embodiment, as shown in FIGS. 1 to 3, from the rear end face 12 </ b> A of the main body 12 to the front end face 24 </ b> A of the insulating covering crimping piece 24 through the end face 25 </ b> A of the core wire crimping piece 25. An insulating coating 29 made of an insulating material is formed on the end face (portion indicated by a bold line in the figure). In the vicinity of the end face 25A of the core wire crimping piece 25, as shown in FIG. 5, the copper (alloy) layer 2, the plating layer 3 covering the copper (alloy) layer 2, and the aluminum (alloy) constituting the exposed core wire 41 are provided. The layers 41 </ b> A overlap in order, and an insulating coating 29 is formed to cover the surface of the plating layer 3 and the end surface 25 </ b> A of the metal substrate 1.

  Further, the surface 23B opposite to the wire placement surface of the terminal 11 (the surface opposite to the surface on which the electric wires are arranged) is almost the entire area of the electric wire connecting portion 23 as shown in FIGS. The film is covered with an insulating film 29 made of an insulating material (the portion shown by shading in the figure). The plating layer 3 on the surface 23B opposite to the wire placement surface of the core wire crimping piece 25 may be peeled off by contact with the crimping fitting when the core wire crimping piece 25 is crimped to the exposed core wire 41. In the embodiment, the insulating film 29 is also formed on the part where the plating layer 3 is peeled off during the pressure bonding.

  Furthermore, in this embodiment, the electric wire placement surface 23A of the terminal 11 is covered with an insulating coating 29 made of an insulating material, except for the connection region 25B to which the exposed core wire 41 is electrically connected, as shown in FIG. ing. Specifically, in the electric wire placement surface 23 </ b> A, a region extending from the front end of the electric wire connection portion 23 to the front side edge of the core wire crimping piece 25 and the rear side edge of the core wire crimping piece 25 to the front end of the insulation coating crimping piece 24. The reaching region is covered with an insulating film 29 made of an insulating material (the portion shown by shading in the figure). As described above, in the present embodiment, since the insulating coating 29 is not formed in the connection region 25B, the electrical connection between the terminal 11 and the electric wire 40 is not adversely affected.

  The insulating coating 29 is preferably made of an insulating material selected from alumite, silica, copper oxide, copper sulfide and the like from the viewpoint of high electrical insulation.

Next, an example of the manufacturing method of the electric wire 10 with a terminal of this embodiment is demonstrated.
First, a pressing process for pressing the metal base 1 made of copper or copper alloy having the plating layer 3 formed on both sides into a predetermined shape (the shape shown in FIG. 3) is performed (pressing process). Pieces 24, 25, etc. are formed.

  Next, when a plurality of concave portions 28 are formed by pressing the connecting region 25B of the core wire crimping piece 25 using a mold in which a plurality of convex portions (not shown) are formed to protrude, the chain terminal shown in FIG. 30 is obtained.

  In the chain terminal 30, a plurality of terminal pieces 11 </ b> A are connected to the carrier 35. As shown in FIG. 3, the chain terminal 30 has a plurality of terminal pieces 11 </ b> A in the illustrated horizontal direction, that is, the longitudinal direction (extending direction) of the carrier 35, with respect to a carrier 35 having a strip shape extending along the illustrated horizontal direction. Are connected in a state of being arranged at substantially equal intervals along the line. Each terminal piece 11 </ b> A has a longitudinal direction in the illustrated vertical direction, that is, a position along the width direction of the chain terminal 30, and the respective front and rear end portions are respectively on one edge in the width direction of the carrier 35. It is connected.

  The rear end portion of the terminal piece 11A is connected to a connecting portion 36 protruding from the side edge of the lower carrier 35 in FIG. The connecting portion 36 is connected to the center of the terminal cover 11 </ b> A in the width direction of the rear end of the insulating coating crimping piece 24. The terminal pieces 11A, the connecting portion 36, and the carrier 35 are arranged side by side in the vertical direction in the drawing, that is, in the width direction when viewed from the entire chain terminal 30. The carrier 35 is formed with feed holes 33 and 34 that can be engaged with feed claws (not shown) provided in the processing machine for feeding the chain terminal 30. Since the feed holes 33 and 34 have different feed claws depending on the type of processing machine (for example, a press or a crimping machine), the circular feed holes 33 and the square feed holes 34 are formed according to the shape of the feed claws. Two types are provided.

  Next, the insulating coating 29 is formed from the end face 12A of the terminal 11 to the front end face 24A of the insulation coating crimping piece 24 via the end face 25A of the core crimping piece 25 from the end face 12A of the terminal portion 11. (Film formation process). In the present embodiment, in the coating forming step, the surface 23B opposite to the wire placement surface and the portion other than the connection region 25B of the wire placement surface 23A (from the front end of the wire connection portion 23 to the core wire crimping piece 25 The insulating coating 29 is also formed on the region extending to the front edge and the region extending from the rear edge of the core crimping piece 25 to the front end of the insulation coating crimping piece 24. When the insulating coating 29 is formed, the insulating coating 29 is prevented from being formed in the connection region 25B by masking the region where the recess 28 is formed (connection region 25B).

The insulating film 29 can be formed by, for example, anodizing, a method of coating SiO ₂ , exposing the copper or copper alloy constituting the metal substrate 1, and performing blackening or sulfuration. Here, since the copper (alloy) is exposed on the end face 12A of the metal substrate 1 after the pressing step, it is not necessary to expose the copper (alloy) when performing the blackening treatment or the sulfidation treatment.

The alumite treatment can be performed, for example, by plating the terminal 11 with aluminum and anodizing the aluminum plating. The coating of SiO ₂ can be performed, for example, by immersing the terminal 11 in an organic solution of polysilazane and baking at a predetermined temperature. The blackening treatment can be performed by, for example, immersing the terminal 11 in a blackening treatment solution containing NaClO ₄ , Na ₃ PO ₄ , and NaOH at 95 ° C. or less for 3 to 15 minutes. The sulfiding treatment can be performed, for example, by immersing the terminal 11 at 10 ° C. for 2 minutes in a sulfiding treatment solution containing ammonium sulfide and potassium hydroxide and having a pH adjusted to 12.3. The sulfidation treatment can also be performed by H ₂ S gas treatment. These methods can also be executed by known methods other than those described above.

  Next, by engaging the feed claws with the feed holes 33 and 34 formed in the carrier 35, the terminal pieces 11A are sequentially sent to the processing machine, and the terminal pieces 11A are bent in the process.

  Next, the insulation coating crimping piece 24 and the core wire crimping piece 25 provided in the wire connection portion 23 of each terminal piece 11 </ b> A are crimped to the electric wire 40, and the terminal 11 and the electric wire 40 are connected. Specifically, as shown in FIG. 4, after placing the end of the electric wire 40 (exposed core wire 41) on the electric wire placement surface 23 </ b> A of the terminal piece 11 </ b> A, Are respectively crimped to the electric wires 40 (crimping step).

  Next, the insulating coating 29 is formed also on the exposed portion of the copper (alloy) such as the portion where the plating layer 3 is peeled off of the core wire crimping piece 25 after the crimping (second coating forming step). The insulating coating 29 is formed by anodizing, sulfurating, exposing the copper or copper alloy constituting the metal substrate 1 and alumite treatment, a method of coating SiO2, and the same as in the above-described coating formation step. can do. By executing the second film forming step, the terminal-attached electric wire 10 having the shape shown in FIGS. 1 and 2 is obtained.

Next, functions and effects of this embodiment will be described.
In the present embodiment, since the insulating coating 29 made of an insulating material is formed on the end face 25A of the crimping piece 25, copper (alloy) is not exposed on the end face 25A of the core wire crimping piece 25. As a result, according to the present embodiment, since electrolytic corrosion can be prevented only by forming the insulating coating 29 on the end face 25A of the core wire crimping piece 25, it is possible to prevent electrolytic corrosion while suppressing the manufacturing cost. The electric wire with terminal 10 and the manufacturing method thereof can be provided.

  Moreover, according to this embodiment, since the insulating coating 29 is formed on the surface 23B opposite to the surface on which the exposed core wire 41 is arranged in the core wire crimping piece 25, copper (alloy) is formed on this surface. ) Can be prevented from being exposed, and thus, electrolytic corrosion can be surely prevented.

  In particular, according to the present embodiment, since the insulating coating 29 is also formed on the exposed portion of the copper (alloy) such as the portion where the plating layer 3 of the terminal 11 is peeled off, the core wire crimping piece 25 is exposed. Since the copper (alloy) is not exposed even when the plating layer 3 is peeled off due to the contact between the crimping fitting (not shown) and the metal substrate 1 by being crimped to the core wire 41, electrolytic corrosion Can be prevented.

  In addition, according to the present embodiment, since the insulating coating 29 is also formed on the surface of the core wire crimping piece 25 where the exposed core wire 41 is disposed, the effect of preventing electrolytic corrosion can be further ensured.

  Moreover, in this embodiment, since the plating layer 3 containing the metal between copper and aluminum is formed on the surface of the metal substrate 1, the ionization tendency is formed on the surface of the metal substrate 1. Since the plating with a metal whose ionization tendency is closer to the metal material [aluminum (alloy)] constituting the core wire 41 is applied, the difference in ionization tendency (potential difference) between the surface of the metal substrate 1 and the core wire 41 is small. As a result, it is difficult for electrolytic corrosion to occur, and the speed of electrolytic corrosion is suppressed. As a result, according to this embodiment, electrolytic corrosion can be reliably prevented.

  In addition, according to the present embodiment, the insulating coating 29 is made of an insulating material selected from alumite, silica, copper oxide, and copper sulfide. Therefore, the insulating coating 29 is made of a material having high electrical insulation, and has high electrolytic corrosion prevention. An effect can be obtained.

<Embodiment 2>
Next, the electric wire with a terminal according to the second embodiment of the present invention will be described with reference to FIG. The electric wire with terminal 50 of the present embodiment is different from the first embodiment in that the insulating coating 29 is not formed on the surface on which the exposed core wire 41 of the core wire crimping piece 25 is disposed. The same reference numerals are given to the same configurations as those in the first embodiment.
Since the configuration other than the above is the same as that of the first embodiment, the same effect as that of the first embodiment can be obtained by the second embodiment.

  In addition, since the insulating coating 29 is not formed in the surface 23A to which the exposed core wire 41 is arranged and connected in the electric wire with terminal 50 of the present embodiment, the electric connection between the electric wire 40 and the terminal 51 is improved. There is an effect that can be.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention.
(1) In the above embodiment, the terminal 11 having the insulating coating 29 formed on the surface 23B of the core wire crimping piece 25 opposite to the surface on which the exposed core wire 41 is disposed is shown. It may be a terminal having an insulating film formed only on the end face.
(2) The region where the insulating coating 29 is formed on the surface 23B opposite to the surface on which the exposed core wire 41 is disposed may be the entire region of the insulating coating crimping piece 24 in addition to the region shown in FIG. 6 (FIG. 8). See).
The form shown in FIG. 8 is different from the form shown in FIG. 6 only in the formation region of the insulating film 29 on the surface 23B opposite to the surface on which the exposed core wire 41 is arranged. ing.

DESCRIPTION OF SYMBOLS 1 ... Metal base material 2 ... Copper (alloy) layer 3 ... Plating layer 10, 50 ... Electric wire with a terminal 11, 51 ... Terminal 23 ... Electric wire connection part 23A ... Electric wire mounting surface (surface where an exposed core wire is arrange | positioned)
23B: Surface opposite to the surface where the exposed core wire is arranged 25: Core wire crimping piece (crimping piece)
25B ... End face (end face of the crimping piece)
29 ... Insulating coating 40 ... Electric wire 41 ... Core wire (exposed core wire)
41A ... Aluminum (alloy) layer 42 ... Wire 43 ... Insulation coating

Claims (3)

Crimping is applied to an electric wire in which a core wire formed by twisting a plurality of strands made of aluminum or aluminum alloy is covered with an insulating coating, and an exposed core wire exposed by peeling off the insulating coating at the end of the electric wire. A terminal having a piece, and a manufacturing method of an electric wire with a terminal comprising:
A press that is made of copper or a copper alloy, and on the surface of which the pressure-bonding piece is formed by pressing a metal base material on which a plating layer containing a metal between copper and aluminum is formed. After executing the process
A film forming step of forming an insulating film made of an insulating material on the end face of the crimping piece is performed,
After performing the crimping step of crimping the crimping piece formed by performing the pressing step to the exposed core wire of the electric wire, the crimping piece is opposite to the wire placement surface on which the electric wire is placed. In the method of manufacturing an electric wire with a terminal, a second film forming step is performed in which an insulating film made of an insulating material is formed on a portion where the plating layer is peeled off in the crimping step. The method for manufacturing an electric wire with terminal according to claim 1 , wherein the plating layer is a plating layer containing tin. The said insulation film is a manufacturing method of the electric wire with a terminal of Claim 1 or Claim 2 which consists of an insulating material chosen from alumite, a silica, copper oxide, and copper sulfide.

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