JP2019057447A - Method of manufacturing terminal - Google Patents

Abstract

To provide a method of manufacturing a terminal, enabling a terminal in which galvanic corrosion is hard to occur to be easily manufactured.SOLUTION: The method of manufacturing a terminal includes: a step S1 of applying nickel plating to a copper plate material 40 as a substrate of a terminal 10, thereby forming a first nickel plating layer 51 on the copper plate material 40; a step S2 of applying tin plating to the steel plate material 40, thereby forming a first tin plating layer 61 on the first nickel plating layer 51; a step S3 of punching the copper plate material 40, thereby forming a terminal constituent plate material 12 in a predetermined shape; a step S5 of removing a part of the first tin plating layer 61, thereby forming a nickel exposure part 55 in which the first nickel plating layer 51 is exposed; a step S6 of applying nickel plating to the nickel exposure part 55, thereby forming a second nickel plating layer 52 on the first nickel plating layer 51; and a step S7 of applying tin plating to the second nickel plating layer 52, thereby forming a second tin plating layer 62 on the second nickel plating layer 52.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a method for manufacturing a terminal, and more particularly to a method for manufacturing a terminal formed of a copper plate material.

  As a material for a terminal attached to an electric wire, copper is often used for reasons such as excellent conductivity and economy. On the other hand, in automobiles and the like, in order to reduce the weight of a vehicle, an aluminum wire made of light aluminum is often used as an electric wire in a wire harness. When a copper terminal is attached to a core wire made of aluminum, if the connecting portion between the core wire and the terminal is exposed to water, a battery circuit is formed between the core wire and the terminal via an electrolyte such as water. The base metal (aluminum) elutes in the electrolyte and corrodes (galvanic corrosion). In order to prevent such galvanic corrosion, a copper terminal is plated and a plating layer is formed on the surface of the terminal.

  However, since such a terminal is generally produced by punching a copper plate material into a predetermined terminal shape and bending it, it is difficult to prevent galvanic corrosion at the end face of the terminal. That is, although the plating layer is formed on the surface of the copper terminal, since the end surface thereof becomes a cut surface at the time of punching, the copper which is the base material is exposed at the end surface. Therefore, galvanic corrosion occurs between the copper exposed at the end face and the aluminum core wire.

  A method of preventing galvanic corrosion by sealing and covering the connecting portion between the core wire of the electric wire and the terminal with a resin has been proposed (see, for example, Patent Document 1). Since it is necessary to apply a predetermined thickness to a predetermined portion, this resin application operation is very complicated. In addition, it is very difficult to manually apply an appropriate amount of resin to an appropriate portion of the terminal, and with this method, it is difficult to stably prevent galvanic corrosion.

JP 2010-108828 A

  The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to provide a method of manufacturing a terminal that can easily manufacture a terminal that is unlikely to cause galvanic corrosion.

  According to one aspect of the present invention, there is provided a method for manufacturing a terminal capable of easily manufacturing a terminal that is unlikely to cause galvanic corrosion. This manufacturing method includes a first nickel plating step of forming a first nickel plating layer on the copper plate by applying nickel plating to a copper plate as a terminal base material, and after the first nickel plating step. The copper plate material is subjected to tin plating to form a first tin plating layer on the first nickel plating layer, and after the first tin plating step, the copper plate material is A punching step for punching to form a terminal-constituting plate material having a predetermined shape, and nickel after removing the first tin plating layer after the punching step to expose the first nickel plating layer A tin removing step for forming an exposed portion; and a second nickel plating layer for forming a second nickel plated layer on the first nickel plated layer by performing nickel plating on the nickel exposed portion after the tin removing step. And second tin plating for forming a second tin plating layer on the second nickel plating layer by applying tin plating to the second nickel plating layer after the second nickel plating step and the second nickel plating step Process.

  Since the terminal manufactured by such a manufacturing method has a tin plating layer formed on the entire surface and end face, galvanic corrosion is unlikely to occur on the surface and end face of the terminal. Further, since the nickel plating layer is formed on the entire surface as the underlayer of the tin plating layer, the effect of suppressing galvanic corrosion is exhibited over a long period of time. The above manufacturing method only adds a plating process and a tin removal process to the conventional terminal manufacturing process, and does not require a process of manually applying a resin. It is possible to manufacture a difficult terminal very easily.

  The terminal may include a crimping portion that is crimped to the electric wire and a connector portion that accommodates therein an elastic piece that is electrically connected to the counterpart terminal. In this case, in the tin removal step, it is preferable to remove the first tin plating layer in a portion constituting the crimp portion of the terminal. By doing in this way, about the crimping | compression-bonding part of a terminal, since a nickel plating layer and a tin plating layer can be formed also in the end surface of the terminal which copper exposed by the punching process, galvanic corrosion is suppressed effectively. be able to.

  Further, it is preferable to perform a terminal forming step of forming the terminal component plate material into the shape of the terminal after the punching step and before the tin removing step. In this case, since the terminal can be formed on the same mold from the punching step, it is difficult to cause a position shift in the terminal forming step, and accurate molding can be realized. Moreover, it can prevent that a plating layer peels off by the bending process in a terminal formation process.

  According to the present invention, a terminal in which galvanic corrosion does not easily occur can be manufactured very simply by simply adding a plating process and a tin removal process to the conventional terminal manufacturing process.

FIG. 1 is a perspective view showing an example of a terminal manufactured by the method for manufacturing a terminal according to the present invention. FIG. 2 is a plan view of the terminal of FIG. FIG. 3 is a flowchart showing a method for manufacturing a terminal according to an embodiment of the present invention. 4A is a schematic cross-sectional view showing the state of the base material after the first nickel plating step of FIG. 4B is a schematic cross-sectional view showing the state of the base material after the first tin plating step of FIG. FIG. 4C is a schematic cross-sectional view showing the state of the base material after the punching step of FIG. FIG. 4D is a schematic cross-sectional view showing a state of the base material after the tin removal step of FIG. 3. 4E is a schematic cross-sectional view showing the state of the base material after the second nickel plating step of FIG. FIG. 4F is a schematic cross-sectional view showing the state of the base material after the second tin plating step of FIG. 3. FIG. 5 is a schematic view showing a punched plate material formed by the punching process of FIG. FIG. 6 is a diagram schematically showing the treatment in the tin removal step of FIG.

  Hereinafter, an embodiment of a method for manufacturing a terminal according to the present invention will be described in detail with reference to FIGS. 1 to 6, the same or corresponding components are denoted by the same reference numerals, and redundant description is omitted. Moreover, in FIG. 1 to FIG. 6, the scales and dimensions of each component are exaggerated and some components may be omitted.

  In order to facilitate understanding of a method for manufacturing a terminal according to the present invention, first, an example of a terminal manufactured by the manufacturing method will be described. FIG. 1 is a perspective view showing an example of a terminal manufactured by the terminal manufacturing method according to the present invention, and FIG. 2 is a plan view. A terminal 10 shown in FIGS. 1 and 2 is formed using copper as a base material, and a crimping portion 20 to be crimped to an electric wire and a counterpart terminal (not shown) are inserted and electrically connected to the counterpart terminal. Connector part 30 to be provided.

  The crimping portion 20 includes a pair of crimping pieces 21 and 21 that are crimped to the core wire exposed at the end of an electric wire (not shown), and a pair of crimping pieces 22 and 22 that are crimped to the sheath of the wire. And have. By positioning the core wire of the electric wire between the crimping pieces 21 and 21, and crimping these crimping pieces 21 and 21, the crimping pieces 21 and 21 are crimped to the core wire, and between the terminal 10 and the core wire Electrical connection is achieved. Similarly, the covering of the electric wire is positioned between the crimping pieces 22, 22, and by crimping these crimping pieces 22, 22, the crimping pieces 22, 22 are crimped to the coating, The electric wire is fixed.

  The connector part 30 has a substantially rectangular parallelepiped outer shape, and an insertion space 31 into which a counterpart terminal is inserted is formed inside. The connector portion 30 includes an elastic piece 32 that extends obliquely inside the insertion space 31, and the elastic piece 32 elastically contacts with a counterpart terminal inserted into the insertion space 31, thereby the terminal 10 and the counterpart terminal. An electrical connection is established between them.

  Next, the manufacturing method of the terminal in one embodiment of the present invention will be described by taking the case of manufacturing the terminal 10 as an example. FIG. 3 is a flowchart showing a process for manufacturing the terminal 10 described above. 4A to 4F are schematic cross-sectional views showing the state of the base material of the terminal in each step of FIG.

  First, as shown in FIG. 4A, when manufacturing the terminal 10, first, a copper plate material 40 as a base material of the terminal is prepared, nickel plating is performed on the copper plate material 40, and nickel plating is performed on the copper plate material 40. The layer 51 is formed (first nickel plating step S1). In this nickel plating, nickel or various nickel alloys can be used as a plating material. Moreover, this 1st nickel plating process S1 can be performed using a well-known method and apparatus.

  Next, as shown in FIG. 4B, tin plating is performed on the copper plate material 40 to form a tin plating layer 61 on the nickel plating layer 51 (first tin plating step S2). In this tin plating, tin or various tin alloys can be used as a plating material. Moreover, this 1st tin plating process S2 can be performed using a well-known method and apparatus.

  And the copper plate material 40 in which the nickel plating layer 51 and the tin plating layer 61 are formed on the surface in this way is transferred to a punching device (not shown), and as shown in FIG. 4C, the copper plate material 40 is transferred by this punching device. A punching plate material 41 having a predetermined shape is formed by punching (punching step S3). At this time, as shown in FIG. 5, in the punched plate material 41, a plurality of terminal constituting plate materials 12 having a shape corresponding to the terminals 10 are formed side by side. Each terminal component plate 12 has a shape that can be formed into a terminal 10 shown in FIG. 1 by bending. Here, as shown in FIG. 4C, the end face 42 of the punched plate member 41 is a punched cut surface, so that copper is exposed.

  In the example shown in FIG. 5, each terminal component plate 12 includes parts 121 and 121 constituting the crimping pieces 21 and 21 of the terminal 10, parts 122 and 122 constituting the crimping pieces 22 and 22, and a connector part. 30 includes a part 130 constituting a rectangular parallelepiped outer shape and a part 132 constituting an elastic piece 32. Further, unevenness is formed on a part of the surface of the terminal component plate 12 by pressing. These terminal component plate members 12 are connected to each other by a connecting portion 43 extending between adjacent terminal component plate members 12.

  Next, by bending each component part of the terminal component plate 12 described above, it is molded into the shape of the terminal 10 as shown in FIG. 1 to produce a terminal molded product (terminal molding step S4). . In addition, this terminal shaping | molding process S4 can be performed using a well-known method and apparatus.

  Thereafter, as shown in FIG. 6, for example, the terminal molded product 10 ′ described above is placed in a bathtub 71 that holds a solvent 70 (for example, STRIP SOLDER-S manufactured by Ishihara Chemical Co., Ltd.) that dissolves tin (or a tin alloy). Only the crimping part 20 is immersed. Thereby, the tin plating layer 61 formed on the surface of the crimping part 20 of the terminal molded product 10 ′ is removed (tin removal step S <b> 5). By this tin removal step S5, as shown in FIG. 4D, the tin plating layer 61 on the copper base material 40 of the crimping part 20 is removed, and the nickel plating layer 51 is exposed to form a nickel exposed part 55. The reason for removing the tin plating layer 61 in this way is that it is difficult to form a nickel plating layer on the tin plating layer 61.

  Next, only the crimping part 20 of the terminal molded product 10 ′ is immersed in, for example, a nickel plating solution to perform nickel plating, thereby forming the nickel plating layer 52 on the nickel exposed part 55 as shown in FIG. 4E. (Second nickel plating step S6). By this second nickel plating step S6, the nickel plating layers 51 and 52 of the crimping part 20 of the terminal molded product 10 ′ become thicker than the nickel plating layer 51 of the connector part 30, and the copper base material 40 of the crimping part 20 The end face 42 is also covered with the nickel plating layer 51. In this nickel plating, nickel or various nickel alloys can be used as a plating material as in the first nickel plating step S1.

  Then, only the crimping portion 20 of the terminal molded product 10 ′ is immersed in, for example, a tin plating solution to perform tin plating, thereby forming a tin plating layer 62 on the nickel plating layer 52 described above, as shown in FIG. 4F. (Second tin plating step S7). By this second tin plating step S <b> 7, in the crimping portion 20, the copper base material 40 is covered with the tin plating layer 62 including the end face 42 of the copper base material 40. In this tin plating, tin or various tin alloys can be used as a plating material as in the first tin plating step S2.

  Through the above-described steps S1 to S7, the terminal 10 having the tin plating layer 61 or 62 formed on the surface can be manufactured.

  In general, galvanic corrosion proceeds faster as the difference in standard electrode potential between different metals electrically connected to each other increases. Since the standard electrode potential difference between tin and aluminum is smaller than the standard electrode potential difference between copper and aluminum, the tin plating layers 61 and 62 are formed on the entire surface of the terminal 10 and the end face of the crimp portion 20 by the above-described steps S1 to S7. By forming, the galvanic corrosion in the surface of the terminal 10 and the end surface of the crimp part 20 is suppressed. Moreover, in the connector part 30, since the tin plating layer 61 is interposing between the copper base material 40 and the other party terminal, the electrical continuity between the other party terminal and the terminal 10 can be improved.

  Further, since the nickel plating layers 51 and 52 are present on the entire surface as the underlayer of the tin plating layers 61 and 62, it is less likely to peel than when the tin plating layers 61 and 62 are formed on the surface of the copper base material 40. It has become. Therefore, the effect of suppressing galvanic corrosion and the effect of improving electrical continuity are exhibited over a long period of time.

  Furthermore, the terminal manufacturing method described above is merely to add a process using a plating material or a solvent to the conventional terminal manufacturing process, and does not require a process of manually applying a resin. Therefore, it is possible to manufacture a terminal that is unlikely to generate galvanic corrosion very easily.

  In the embodiment described above, the nickel plating step and the tin plating step are performed before and after the terminal forming step S4, respectively, but the terminal forming is not performed without performing the first nickel plating step S1 and the first tin plating step S2. It seems that the same effect can be obtained even if the second nickel plating step S6 and the second tin plating step S7 are performed on the entire terminal molded product 10 ′ after the step S4. However, since the connector part 30 of the terminal molded product 10 ′ after the terminal molding process S4 has a complicated shape, if the terminal molded product 10 ′ is plated, the plating thickness of the connector part 30 varies. Will occur. As a result, a change occurs in the pressure at which the elastic piece 32 comes into contact with the counterpart terminal, and it may be difficult to ensure stable electrical continuity between the counterpart terminal and the terminal 10. On the other hand, in the above-mentioned embodiment, since the nickel plating and the tin plating are performed on the connector portion 30 in the state of the copper plate material 40 before the terminal molding step S4, the thickness of the plating layer by these plating is small. It becomes uniform. In addition, for the crimping part 20 where galvanic corrosion is a problem, after the tin plating layer is removed after the terminal forming step S4, the nickel plating and the tin plating are performed again to thereby expose the copper in the punching step S3. A nickel plating layer and a tin plating layer can also be formed on the ten end faces 42. Therefore, galvanic corrosion can be effectively suppressed even at the end face 42 of the terminal 10 where copper is exposed in the punching step S3.

  The terminal forming step S4 described above may be performed any time after the punching step S3, but is performed immediately after the punching step S3 and before the tin removing step S5 as in the above-described embodiment. It is preferable. In this way, since the terminals can be molded on the same die from the punching process, it is difficult to cause a positional shift in the terminal molding process, and accurate molding can be realized. Moreover, when performing a terminal shaping | molding process after a tin removal process, a 2nd nickel plating process, and a 2nd tin plating process, the plating layer formed in the 2nd nickel plating process and the 2nd tin plating process However, peeling of the plating layer can be prevented by performing the terminal forming step before the tin removing step.

  The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and it goes without saying that the present invention may be implemented in various forms within the scope of the technical idea.

DESCRIPTION OF SYMBOLS 10 Terminal 10 'Terminal molded product 12 Terminal component board material 20 Crimp part 21,22 Clamping piece 30 Connector part 31 Insertion space 32 Elastic piece 40 Copper board material 41 Punching board material 42 End surface 51 Nickel plating layer (1st nickel plating layer)
52 Nickel plating layer (second nickel plating layer)
55 Nickel exposed part 61 Tin plating layer (first tin plating layer)
62 Tin plating layer (second tin plating layer)
70 Solvent 71 Bathtub

Claims (3)

A first nickel plating step of forming a first nickel plating layer on the copper plate by applying nickel plating to the copper plate as a terminal substrate;
After the first nickel plating step, a first tin plating step of performing tin plating on the copper plate material to form a first tin plating layer on the first nickel plating layer;
After the first tin plating step, a punching step of punching the copper plate material to form a terminal-constituting plate material having a predetermined shape;
After the punching step, a tin removal step of forming a nickel exposed portion in which a part of the first tin plating layer is removed to expose the first nickel plating layer;
A second nickel plating step of forming a second nickel plating layer on the first nickel plating layer by performing nickel plating on the nickel exposed portion after the tin removal step;
And a second tin plating step of forming a second tin plating layer on the second nickel plating layer by applying tin plating to the second nickel plating layer after the second nickel plating step. A method of manufacturing a terminal characterized by the above. The terminal includes a crimping portion to be crimped to the electric wire, and a connector portion for accommodating therein an elastic piece electrically connected to the counterpart terminal,
2. The method for manufacturing a terminal according to claim 1, wherein, in the tin removal step, the first tin plating layer in a portion constituting the crimp portion of the terminal is removed.   The terminal according to claim 1, further comprising a terminal forming step of forming the terminal component plate material into the shape of the terminal after the punching step and before the tin removing step. Manufacturing method.

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