JP4267510B2 - Evaluation method of contact load of press contact terminal - Google Patents

Description

The present invention relates to the evaluation (calculated) how the contact load of the pressure contact terminal seeking proper contact load between the core wire of the electric wire pressure contact terminal constituting the wire harness arranged in a car or a vehicle.

  Various electronic devices are mounted on automobiles as vehicles. For this reason, the said automobile has wired the wire harness. The wire harness includes a plurality of electric wires and connectors. The electric wire includes a conductive core wire and an insulating covering portion that covers the core wire. The connector includes a terminal fitting made of metal and an insulating connector housing that houses the terminal fitting. The terminal fitting is attached to the electric wire and electrically connected to the core wire of the electric wire. The connector housing is formed in a cylindrical shape or a box shape and accommodates the terminal fitting described above.

  The wire harness having the above-described configuration is routed in an automobile such that the connector is fitted to the connector of the electronic device described above. And a wire harness electrically connects each electric wire and an electronic device via the terminal metal fitting etc. which were mentioned above. The wire harness electrically connects the electronic devices described above according to a predetermined pattern, and supplies necessary signals and electric power to each electronic device.

  As the above-mentioned terminal fitting, for example, a plurality of press contact blades are provided, and an electric wire is press-fitted between these press contact blades, and the press contact blade cuts the coating portion of the wire and comes into contact with the core wire, thereby electrically connecting to the electric wire. In some cases, a press contact terminal (see, for example, Patent Document 1) is used. The above-described press contact terminals are formed by punching or bending a sheet metal having corrosion-resistant plated layers formed on both surfaces.

The above-described press contact terminal disclosed in Patent Document 1 is subjected to bending so that the core of the wire press-fitted between the press contact blades and the plating layer are in direct contact. And the press contact terminal prevents the electrical resistance value with the core wire from increasing with the contact with the core wire in the plating layer, and ensures the reliability of the electrical connection with the core wire. Yes.
JP 2000-348788 A

  The above-described press contact terminal disclosed in Patent Document 1 is manufactured by performing a complicated bending process so that the plating layer contacts the core wire. For this reason, the press-contact terminal disclosed in Patent Document 1 described above is bent or manufactured because the shape of the mold to be bent becomes complicated, the number of molds increases and the number of bending processes increases. There was a tendency for costs to increase.

  Further, even if the above-described sheet metal is punched and then a plating layer is formed on the outer surface to simplify the above-described bending process of the press contact blade, it is conceivable that the plating layer makes contact with the core wire. In this case, the cost required for the bending process can be reduced, but since the plating is performed again after the punching process is performed, the number of processes required for forming the plating layer is increased, and thus the manufacturing cost tends to increase. Met.

  For this reason, the above-described press contact terminal is required to ensure the reliability of electrical connection even if it contacts the core wire at a place where no plating is formed. In the case where the end face where the base material not plated with the press contact blade is exposed is brought into direct contact with the core wire, if the contact load between the press contact blade and the core wire is too weak, It is considered that rust occurs between the core wires. Furthermore, if the contact load between the press contact blade and the core wire is too weak, rust generated on the end face before press contact cannot be removed.

Therefore, the object of the present invention is to provide a pressure contact blade and a core wire that can ensure the reliability of electrical connection with the core wire even when the pressure contact blade is not plated and the base wire is exposed on the surface where the base material is exposed. and to provide an evaluation (calculated) how the contact load of the pressure contact terminal that can determine the appropriate contact load.

  In order to solve the above problems and achieve the object, the method for evaluating (calculating) the contact load of the press contact terminal according to the present invention includes a press contact blade that contacts the core wire of the press contact terminal, and the core wire. In the method of evaluating the contact load of the press contact terminal for obtaining an appropriate contact load, the base material constituting the press contact terminal is exposed at the end surface of the press contact blade contacting the core wire, and the contact load with the core wire is A plurality of different pressure contact terminals are manufactured, and after the weather resistance test is performed on the plurality of pressure contact terminals, the wire is pressed against the pressure contact blade to remove rust from the end surface of the pressure contact blade. The first lower limit is obtained, a plurality of press contact terminals having different contact loads with the core wire are manufactured, a weather resistance test is performed on the plurality of press contact terminals, and then an electric wire is connected to the press contact blade of the plurality of press contact terminals. The weather resistance test was performed after the pressure contact The second lower limit value of the contact load capable of preventing rust between the end face of the press contact blade and the core wire is obtained, and a value satisfying the first lower limit value and the second lower limit value is obtained. The suitable contact load is used.

  The method for evaluating (calculating) the contact load of the press contact terminal according to claim 2 is the method for evaluating (calculating) the contact load of the press contact terminal according to claim 1, wherein the first lower limit value of the contact load is used. Is determined by measuring an electrical resistance value between each of the press contact terminals in which the electric wire is press-contacted to the press contact blade and the core wire, and a first of the contact load and the electrical resistance value is measured. A relationship is obtained, and a value that is equal to or less than the electrical resistance value between the press contact terminal and the core wire, in which the electrical resistance value is regarded as a non-defective product, is obtained from the first relationship, and this value is calculated as the first lower limit value. It is characterized by that.

  The method for evaluating (calculating) the contact load of the press contact terminal according to claim 3 is the method for evaluating (calculating) the contact load of the press contact terminal according to claim 2, wherein the first lower limit value of the contact load is used. When a plurality of press contact terminals having a plating layer formed on the end face and having different contact loads with the core wire are manufactured, a weather resistance test is performed on the plurality of press contact terminals, and then the press contact blade is applied to the press contact blade. The electric wire is pressure-contacted, and an electrical resistance value between each press-contact terminal and the core wire is measured to obtain a second relationship between the contact load and the electrical resistance value, and the first The first lower limit value is obtained based on the relationship and the second relationship.

  The method for evaluating (calculating) the contact load of the press contact terminal according to claim 4 is the method for evaluating (calculating) the contact load of the press contact terminal according to claim 1, wherein the second lower limit value of the contact load is used. When determining the electrical resistance value between the core wire and each press contact terminal subjected to a weather resistance test and subjected to a weather resistance test by pressing the wire against the press contact blade, the contact A third relationship between the load and the electrical resistance value is obtained, and the electrical resistance value is less than or equal to the electrical resistance value between the press contact terminal and the core wire, which is regarded as a non-defective product, from the third relationship. A value is obtained, and this value is set as the second lower limit value.

  The method for evaluating (calculating) the contact load of the press contact terminal according to claim 5 is the method for evaluating (calculating) the contact load of the press contact terminal according to claim 4, wherein the second lower limit value of the contact load is used. When a plurality of press contact terminals having a plating layer formed on the end surface and different contact loads are manufactured, a weather resistance test is performed, and an electric wire is press-contacted to the plurality of press contact terminals and a weather resistance test is performed. Then, an electrical resistance value between each press contact terminal and the core wire is measured to obtain a fourth relation between the contact load and the electrical resistance value, and the third relation and the fourth relation are obtained. Based on the relationship, the second lower limit value is obtained.

  The method for evaluating (calculating) the contact load of the press contact terminal according to claim 6 of the present invention is the method for evaluating (calculating) the contact load of the press contact terminal according to any one of claims 1 to 5. Then, after obtaining the first lower limit value, a weather resistance test is performed on the pressure contact terminal in which the electric wire used when obtaining the first lower limit value is obtained, and the second lower limit value is obtained. It is said.

  According to the method for evaluating (calculating) the contact load of the press contact terminal according to the first aspect of the present invention, a weather resistance test is performed on each of the plurality of press contact terminals having different contact loads before press contact of the wire, and the wire is pressed. Then, the first lower limit value of the contact load at which rust is removed from the end face in contact with the core wire of the press contact blade is obtained. In addition, a weather resistance test is performed again on each of a plurality of press contact terminals that are subjected to a weather resistance test and have different contact loads after the press contact of the electric wire, and rust is generated between the end surface that contacts the core wire of the press contact blade and the core wire. A second lower limit value of the contact load that can prevent the above is obtained. A value satisfying the first lower limit value and the second lower limit value is defined as a contact load between the end face of the press contact blade and the core wire.

  Since the contact load is equal to or greater than both the first lower limit value and the second lower limit value, even if rust occurs on the end face of the press contact blade of the press contact terminal, if the electric wire is pressed into the press contact blade, the core wire and the press contact blade Rust can be removed from between. Moreover, it can prevent that rust arises between the end surface of a press-contacting blade, and a core wire, after pressing an electric wire to a press-contact terminal.

  According to the method for evaluating (calculating) the contact load of the press contact terminal according to the second aspect of the present invention, the electrical resistance value between each press contact terminal and the core wire and the contact load between the core wire of each press contact terminal 1 is obtained, a contact load value that is equal to or lower than the electrical resistance value of the non-defective product is obtained from this first relationship, and this value is set as a first lower limit value of the contact load. For this reason, the first lower limit value can be accurately obtained, and even if rust occurs on the end face of the press contact blade of the press contact terminal, if the electric wire is press contacted to the press contact blade, the rust is surely ensured between the core wire and the press contact blade. Can be removed.

  According to the method for evaluating (calculating) the contact load of the press contact terminal according to the third aspect of the present invention, the electrical resistance value of each press contact terminal having a plating layer formed on the end face and the core wire, and the press contact terminal A second relationship with the contact load with the core wire is obtained, and a first lower limit value is obtained based on the first relationship and the second relationship. The first lower limit value is the value of the contact load before the difference in electrical resistance value begins to occur between the first relationship and the second relationship as the contact load is gradually reduced. Is desirable.

  When the first lower limit value is obtained in this way, the electrical resistance value between the core wire and the press contact terminal can be maintained as in the case where the plating layer is formed on the end face.

  According to the method for evaluating (calculating) the contact load of the press contact terminal according to the fourth aspect of the present invention, the electrical resistance value between each press contact terminal and the core wire and the contact load between the core wire of each press contact terminal 3 is obtained, and from this third relation, the value of the contact load that is equal to or lower than the electrical resistance value of the non-defective product is obtained, and this value is set as the second lower limit value of the contact load. For this reason, the second lower limit value can be accurately obtained, and it is possible to reliably prevent rust from being generated between the end face of the press contact blade and the core wire after pressurizing the electric wire to the press contact terminal.

  According to the method for evaluating (calculating) the contact load of the press contact terminal according to the fifth aspect of the present invention, the electrical resistance value between each press contact terminal having a plating layer formed on the end face and the core wire, and each press contact terminal A fourth relationship with the contact load with the core wire is obtained, and a second lower limit value is obtained based on the third relationship and the fourth relationship. The second lower limit value is the value of the contact load before the difference in electrical resistance value begins to occur between the third relationship and the fourth relationship when the contact load is gradually reduced. Is desirable.

  When the second lower limit value is obtained in this way, the electrical resistance value between the core wire and the press contact terminal can be maintained as in the case where the plating layer is formed on the end face.

  According to the method for evaluating (calculating) the contact load of the press contact terminal according to the sixth aspect of the present invention, the first lower limit value and the second lower limit value are obtained using the same press contact terminal. For this reason, resource saving can be achieved.

  In addition, the weather resistance test described in this specification means that the test object such as a pressure contact terminal or a pressure contact terminal where a wire is pressed is left in an artificially created atmosphere such as rain, high temperature, low temperature, and high humidity. Thus, a test for knowing the weather resistance of the test object such as the above-described pressure contact terminal and the pressure contact terminal to which the electric wire is pressure contacted is shown. For this reason, the weather resistance test described in this specification indicates a so-called atmospheric exposure test.

  As described above, in the present invention according to claim 1, the contact load with the core wire of the press contact blade of the press contact terminal is equal to or greater than both the first lower limit value and the second lower limit value. Even if rust occurs on the end face of the press contact blade, rust can be removed from between the core wire and the press contact blade by pressing the electric wire to the press contact blade. For this reason, even if the end face of the press contact blade corrodes before the press contact of the wire, if the wire is pressed, rust is removed from between the core wire and the press contact blade, and the electrical resistance value with the core wire of the press contact terminal increases. Can be prevented.

  Moreover, it can prevent that rust arises between the end surface of a press-contacting blade, and a core wire, after pressing an electric wire to a press-contact terminal. Even if the end face of the press contact blade is about to be corroded after the electric wire is pressed, rust does not occur between the core wire and the press contact blade, and an increase in the electrical resistance value with the core wire of the press contact terminal can be prevented.

  Therefore, if the contact load with the core wire of the press contact blade is maintained above both the first lower limit value and the second lower limit value, the core wire is exposed on the surface where the base material to which the press contact blade is not plated is exposed. Even if it contacts, it can prevent that an electrical resistance value with a core wire increases by aging. For this reason, the reliability of the electrical connection with a core wire is securable. In this way, even when the base metal that is not plated with the press contact blade is exposed to the core wire, the contact load between the press contact blade and the core wire can ensure the reliability of electrical connection with the core wire. Can be requested.

  The present invention according to claim 2 determines a first relationship between an electrical resistance value between each press contact terminal and the core wire and a contact load between each press contact terminal and the core wire, and the contact load is determined from the first relationship. The first lower limit value is obtained. For this reason, the first lower limit value can be accurately obtained, and even if rust occurs on the end face of the press contact blade of the press contact terminal, if the electric wire is press contacted to the press contact blade, the rust is surely ensured between the core wire and the press contact blade. Can be removed. Therefore, it is possible to ensure an appropriate contact load between the press contact blade and the core wire, which can ensure the reliability of the electrical connection with the core wire even if it contacts the core wire on the exposed surface of the base material to which the press contact blade is not plated. Can be requested.

  According to the third aspect of the present invention, the core wire and the pressure contact terminal are equivalent to those in which the plating layer is formed on the end face by obtaining the first lower limit value based on the first relationship and the second relationship. It is possible to keep the electrical resistance value between. Therefore, even if the base metal that is not plated with the press contact blade is exposed to the core wire, an appropriate contact load between the press contact blade and the core wire can be secured to ensure the reliability of electrical connection with the core wire. It can be determined more reliably.

  The present invention according to claim 4 obtains a third relationship between the electrical resistance value of each press contact terminal and the core wire and the contact load between the core wire of each press contact terminal and the contact load from the third relationship. The second lower limit value is obtained. For this reason, the second lower limit value can be accurately obtained, and it is possible to reliably prevent rust from being generated between the end face of the press contact blade and the core wire after pressurizing the electric wire to the press contact terminal. Therefore, it is possible to ensure an appropriate contact load between the press contact blade and the core wire, which can ensure the reliability of the electrical connection with the core wire even if it contacts the core wire on the exposed surface of the base material to which the press contact blade is not plated. Can be requested.

  In the present invention according to claim 5, the core wire and the press contact terminal are equivalent to those in which the plating layer is formed on the end face by obtaining the first lower limit value based on the third relation and the fourth relation. It is possible to keep the electrical resistance value between. Therefore, even if the base metal that is not plated with the press contact blade is exposed to the core wire, an appropriate contact load between the press contact blade and the core wire can be secured to ensure the reliability of electrical connection with the core wire. It can be determined more reliably.

  In the present invention described in claim 6, the first lower limit value and the second lower limit value are obtained using the same pressure contact terminal. For this reason, resource saving can be achieved.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS. In the method for evaluating a contact load of a press contact terminal according to an embodiment of the present invention, the press contact terminal 1 in which the contact load F with the core wire 3 of the electric wire 2 is determined is formed by bending a conductive sheet metal or the like. . Of course, the electric wire 2 pressed against the press contact terminal 1 is a so-called covered electric wire provided with a conductive core wire 3 and an insulating covering portion 4 as shown in FIG. The core wire 3 is configured by twisting a plurality of strands. Each strand is made of a conductive metal. The covering portion 4 is made of an insulating synthetic resin and covers the core wire 3.

  As shown in FIGS. 1A and 1B, the press contact terminal 1 is integrally provided with a wire connecting portion 5 and an electrical contact portion 6. The electric wire connecting portion 5 includes a flat bottom wall 7 on which the electric wire 2 is positioned, a pair of side walls 8, a plurality of press contact portions 9, and a pair of caulking pieces 10. The planar shape of the bottom wall 7 is formed in a rectangular shape. The pair of side walls 8 are erected from both edges of the bottom wall 7 in the width direction. The pair of side walls 8 are opposed to each other with a space therebetween.

  The plurality of press contact portions 9 are arranged at intervals along the longitudinal direction of the bottom wall 7, that is, the wire connection portion 5. Each press contact portion 9 includes a pair of press contact blades 11a and 11b. The press contact blades 11 a and 11 b are erected with respect to the bottom wall 7. One press contact blade 11 a is connected to one side wall 8, and the other press contact blade 11 b is connected to the other side wall 8. The pair of press contact blades 11 a and 11 b extend from the side wall 8 in a direction approaching each other. The pair of press contact blades 11 a and 11 b are arranged at intervals from each other along the width direction of the bottom wall 7, that is, the electric wire connection portion 5.

  As shown in FIGS. 2 and 3, the press contact portion 9 presses the electric wire 2 between the press contact blades 11 a and 11 b, thereby cutting the covering portion 4 of the electric wire 2 so that the pair of press contact blades 11 a and 11 b are opposed to each other. An end face 12 (opposite to the core wire 3 of the electric wire 2) contacts the core wire 3 and is electrically connected to the electric wire 2. That is, it is in pressure contact with the electric wire 2.

  At this time, as shown in FIGS. 2 and 3, the press contact portion 9 generates a contact load F in a direction in which the pair of press contact blades 11 a and 11 b sandwich the core wire 3 of the electric wire 2 between each other. For this reason, when the electric wire 2 is press-contacted to the press contact terminal 1, the contact load F described above is generated between the end faces 12 of the press contact blades 11 a and 11 b and the core wire 3 of the electric wire 2. Further, the contact load F can be variously changed by changing dimensions such as thickness and width of the press contact blades 11a and 11b and a bending method.

  The pair of caulking pieces 10 are provided at one end of the wire connecting portion 5. The caulking pieces 10 are erected from both edges of the bottom wall 7 in the width direction. As shown in FIG. 1B, the pair of caulking pieces 10 are bent so that the edge on the side away from the bottom wall 7 approaches the bottom wall 7, and the electric wire 2 is sandwiched between the bottom wall 7. Then, the electric wire 2 is fixed. Thus, the pair of caulking pieces 10 caulks the electric wire 2.

  The electrical contact portion 6 is connected to the other end portion in the longitudinal direction of the wire connection portion 5. The electrical contact portion 6 includes a cylindrical tube portion 13 and a spring piece 14. The cylindrical portion 13 is continuous with the bottom wall 7 and the pair of side walls 8. The spring piece 14 is accommodated in the cylindrical portion 13, and a tab of a mating terminal fitting (not shown) that has entered the cylindrical portion 13 is pressed against the inner surface of the cylindrical portion 13 to fix the mating terminal fitting. .

  The press contact terminal 1 having the above-described configuration is manufactured as follows. First, as shown in FIGS. 5 and 6, a sheet metal 22 having a plating layer 21 formed on both surfaces 20 a and 20 b of the plate-like base material 20 constituting the press contact terminal 1 shown in cross section in FIG. 4 is obtained. A copper alloy such as copper or brass is used as the metal constituting the base material 20. As the base material 20, a metal having relatively low corrosion resistance is used. As the metal constituting the plating layer 21, tin, tin alloy, or the like is used. As the metal constituting the plating layer 21, it is desirable to use a metal having high corrosion resistance.

  Then, as shown in FIG. 7, the above-described press contact terminal 1 is formed by punching (pressing) a sheet metal 22 obtained by forming the plating layer 21 on the surfaces 20a and 20b of the base material 20 described above. The unnecessary portion is removed leaving the portion 23 to be connected and the chain band 24 for connecting the portions 23 for forming the press contact terminals 1 to each other. In the state shown in FIG. 7, a plurality of portions 23 for molding the above-described press contact terminal 1 are provided in parallel to each other, and the chain strip 24 is formed in a strip shape in which one ends of the bottom wall 7 of the press contact terminal 1 are connected to each other. . Furthermore, holes 25 for feeding the sheet metal 22 by a predetermined length are provided in the chain band 24 at equal intervals.

  Then, as shown in FIG. 8, the above-described press contact terminal 1 is formed by bending (pressing) the sheet metal 22 from which unnecessary portions have been removed. Then, after these press contact terminals 1 are separated from the chain band 24 and inserted into a terminal housing chamber of a connector housing (not shown), the electric wire 2 is press-fitted between the press contact blades 11 a and 11 b of the press contact portion 9. Thus, the above-described press contact terminal 1 is manufactured and assembled to the connector. The connector assembled in this way constitutes a wire harness routed in an automobile or the like, and supplies necessary signals and electric power to each electronic device mounted in the automobile.

  Further, as described above, the press contact blades 11 a and 11 b extend from the side wall 8 in a direction approaching each other, and after the plating layer 21 is formed, punching is performed to obtain the press contact terminal 1. For this reason, as shown in FIG. 3, in the press contact terminal 1, the base material 20 is exposed on the end face 12 of the press contact blades 11 a and 11 b that are in contact with the core wire 3. As shown in FIG. 3, the press contact terminal 1 has the base material 20 in direct contact with the core wire 3 without the plating layer 21 in contact with the core wire 3.

  The above-described contact load F is determined for the press contact terminal 1 having the above-described configuration and manufactured as described above. First, in step S1 and step S7 in FIG. 9, a plurality of press contact terminals 1 having the configuration shown in FIG. 1 and the like and having different contact loads F are manufactured. And it progresses to both step S2 and step S8.

  In step S2, a predetermined weather resistance test is performed on each of the plurality of press contact terminals 1 having different contact loads F with the core wire 3. Then, since the base material 20 is exposed, rust is generated on the end surfaces 12 of the press contact blades 11a and 11b described above. Then, the process proceeds to step S3.

  In step S <b> 3, the electric wire 2 is press-fitted between the press contact blades 11 a and 11 b of the plurality of press contact terminals 1 having different contact loads F with the core wire 3. That is, the electric wire 2 is press-contacted to each press-contact terminal 1. As the contact load F increases, the frictional force between the core wire 3 and the end surfaces 12 of the press contact blades 11a and 11b when the electric wire 2 is pressed is increased, and rust is removed from the end surface 12 described above. It will be. Then, the process proceeds to step S4.

  In step S4, the electrical resistance value between each press contact terminal 1 and the core wire 3 of the electric wire 2 press-contacted to each press contact terminal 1 is measured. Then, a first relationship A between the contact load F of each press contact terminal 1 indicated by a one-dot chain line in FIG. 10 and the electrical resistance value between each press contact terminal 1 and the core wire 3 is obtained. At this time, a regression curve of actually measured values (indicated by white squares in FIG. 10) is obtained, and the regression curve is defined as the first relationship A described above. Then, the process proceeds to step S5.

  In step S5, a plurality of press-contact terminals having the plating layer 21 formed on the end face 12 and having different contact loads F with the core wire 3 are manufactured. The same weather resistance test as in step S2 described above is performed on each press contact terminal having the plating layer 21 formed on the end face 12. And an electric wire is press-contacted to each press-contact terminal by which the plating layer 21 was formed in the end surface 12. FIG.

  The electrical resistance value between each press contact terminal in which the plating layer 21 is formed on the end face 12 and the core wire of the electric wire press-contacted to each press contact terminal is measured. And the 2nd relationship B of the contact load F of each press contact terminal in which the plating layer 21 was formed in the end surface 12 shown as a continuous line in FIG. 10, and the electrical resistance value between each press contact terminal and a core wire is shown. Ask. At this time, a regression curve of actually measured values (indicated by white circles in FIG. 10) is obtained, and the regression curve is defined as the second relationship B described above. Since the second relationship B indicates the electrical resistance value between the press contact terminal having the plating layer 21 formed on the end face 12 and the electric wire, the end face 12 has no rust, that is, the non-defective press contact terminal. The electrical resistance value with the electric wire is shown. According to FIG. 10, the electrical resistance values overlap each other when the contact load F increases, and the difference between the electrical resistance values increases as the contact load F decreases. Then, the process proceeds to step S6.

  In step S6, the value X of the contact load F and the electrical resistance value before the difference begins to occur between the first relationship A and the second relationship B shown in FIG. When the value X is equal to or greater than X, the press contact terminal 1 where the base material 20 is exposed from the end face 12 has the same electrical resistance value as the press contact terminal having the plating layer 21 formed on the end face 12. That is, when the contact load F is equal to or greater than the above-described value X, the electrical resistance value of the press contact terminal 1 at which the base material 20 is exposed from the end face 12 is equal to the electrical resistance value of the press contact terminal that is a good product. (Below)

  Thus, the first lower limit value X of the contact load F is obtained based on the first relationship A and the second relationship B. The first lower limit value X is a value of the contact load F that can remove rust from the end faces 12 of the press contact blades 11a and 11b of the press contact terminal 1 subjected to a weather resistance test before the wire 2 is pressed. In this way, the value X of the contact load F that is equal to or less than the electrical resistance value of the press contact terminal 1, which is regarded as a non-defective product, is obtained, and this value X is set as the first lower limit value of the contact load F. . After step S6, the process proceeds to step S14.

  In step S8, a predetermined weather resistance test is performed on each of the plurality of press contact terminals 1 having different contact loads F with the core wire 3. Then, since the base material 20 is exposed, rust is generated on the end surfaces 12 of the press contact blades 11a and 11b described above. Then, the process proceeds to step S9.

  In step S9, the electric wire 2 is press-fitted between the press contact blades 11a, 11b of the plurality of press contact terminals 1 having different contact loads F with the core wire 3. That is, the electric wire 2 is press-contacted to each press-contact terminal 1. At this time, as in step S3 described above, as the contact load F described above increases, the frictional force between the core wire 3 and the end faces 12 of the press contact blades 11a and 11b increases when the electric wire 2 is pressed. The rust is removed from the end face 12 described above. Then, the process proceeds to step S10.

  In step S10, a predetermined weather resistance test is again performed on each press contact terminal 1 in which the contact load F with the core wire 3 is different from each other and the electric wire 2 is press contacted. As the above-described contact load F increases, the end surfaces 12 of the press contact blades 11a and 11b and the core wire 3 come into close contact with each other, and rust is unlikely to be generated between the end surfaces 12 of the press contact blades 11a and 11b and the core wire 3. Become. Then, the process proceeds to step S11.

  In step S11, an electrical resistance value between each press contact terminal 1 and the core wire 3 of the electric wire 2 press-contacted to each press contact terminal 1 is measured. Then, a third relationship C between the contact load F of each press contact terminal 1 indicated by a dotted line in FIG. 11 and the electrical resistance value between each press contact terminal 1 and the core wire 3 is obtained. At this time, a regression curve of actually measured values (indicated by black squares in FIG. 11) is obtained, and the regression curve is set as the third relationship C described above. Then, the process proceeds to step S12.

  In step S <b> 12, a plurality of press contact terminals having the plating layer 21 formed on the end face 12 and having different contact loads F with the core wire 3 are manufactured. And an electric wire is press-contacted to each press-contact terminal by which the plating layer 21 was formed in the end surface 12. FIG. The same weather resistance test as in step S10 described above is performed on each press contact terminal on which the plating layer 21 is formed on the end face 12 and the electric wire is press contacted.

  The electrical resistance value between each press contact terminal in which the plating layer 21 is formed on the end face 12 and the core wire of the electric wire press-contacted to each press contact terminal is measured. And the 4th relationship between the contact load F of each press contact terminal by which the plating layer 21 was formed in the end surface 12 shown with a dashed-two dotted line in FIG. 11, and the electrical resistance value between each press contact terminal and a core wire is shown. D is obtained. At this time, a regression curve of actually measured values (indicated by black circles in FIG. 11) is obtained, and the regression curve is set as the fourth relation D described above. The fourth relationship D indicates the electrical resistance value between the press contact terminal having the plating layer 21 formed on the end face 12 and the electric wire, and therefore no rust is generated between the end face 12 and the core wire 3, that is, a non-defective product. The electrical resistance value with the electric wire of the press-contacting terminal is shown. According to FIG. 11, the electrical resistance values overlap each other when the contact load F increases, and the difference between the electrical resistance values increases as the contact load F decreases. Then, the process proceeds to step S13.

  In step S13, the value Y and the electrical resistance value of the contact load F before the difference starts to appear between the third relationship C and the fourth relationship D shown in FIG. When the contact load F is equal to or greater than this value Y, the press contact terminal 1 where the base material 20 is exposed from the end face 12 has the same electrical resistance value as the press contact terminal having the plating layer 21 formed on the end face 12. That is, if the contact load F is greater than or equal to the value Y, the electrical resistance value of the press contact terminal 1 at which the base material 20 is exposed from the end face 12 is equal to the electrical resistance value of the press contact terminal that is a non-defective product (hereinafter referred to as “good”) become).

  Thus, the second lower limit value Y of the contact load F is obtained based on the third relationship C and the fourth relationship D. This second lower limit value Y is a value of the contact load F that can prevent rust from occurring between the end face 12 of the press contact blades 11a, 11b of the press contact terminal 1 subjected to the weather resistance test after the press contact of the electric wire 2 and the core wire 3. It is. In this way, the value Y of the contact load F that makes the electrical resistance value equal to or less than the electrical resistance value of the press contact terminal that is regarded as a non-defective product is obtained, and this value Y is set as the second lower limit value of the contact load F. After step S13, the process proceeds to step S14.

  In step S14, the appropriate contact load F of the press contact terminal 1 described above satisfies a value that satisfies both the first lower limit value X determined in step S6 described above and the second lower limit value Y determined in step S13 described above. Determine. Thus, an appropriate contact load F that satisfies both the first lower limit value X and the second lower limit value Y of the press contact terminal 1 is determined. The appropriate contact load F thus determined is, of course, not less than the first lower limit value X described above and not less than the second lower limit value Y.

  In the press contact terminal 1 having the above-described configuration, the contact load F is set to a value satisfying both the first lower limit value X and the second lower limit value Y obtained as described above. For this reason, the press contact terminal 1 having the above-described configuration in which the base material 20 is exposed from the end surfaces 12 of the press contact blades 11a and 11b, even if rust is generated on the end surface 12 before the press contact of the wire 2, Rust on the end face 12 can be reliably removed.

  In addition, the press contact terminal 1 having the above-described configuration in which the base material 20 is exposed from the end surfaces 12 of the press contact blades 11 a and 11 b is formed between the end surface 12 and the core wire 3 even if rust is generated on the end surface 12 after the press contact of the electric wire 2. It is possible to surely prevent rust from occurring between them. For this reason, in the press contact terminal 1 having the above-described configuration, the electrical resistance value with the core wire 3 of the electric wire 2 is equal to the electrical resistance value of the press contact terminal 1 in which the plating layer 21 is formed on the end face 12. That is, the press contact terminal 1 having the above-described configuration prevents an increase in electrical resistance value with the core wire 3 of the electric wire 2 over time even when the base material 20 is exposed from the end surface 12. The reliability of electrical connection with the core wire 3 can be ensured.

  Furthermore, since the above-mentioned press contact terminal 1 can ensure the reliability of the electrical connection with the core wire 3 of the electric wire 2 without forming the plating layer 21 on the end face 12 of the press contact blade 11a, 11b, the press contact blade 11a, It is possible to easily perform the bending process when forming 11b, and it is not necessary to form the plating layer 21 on the end face 12 again. Therefore, it is possible to reduce labor, man-hours, mold costs, and the like for manufacturing the press contact terminal 1, and to reduce the cost of the press contact terminal 1.

  In this specification, the weather resistance test means that the test object such as the press contact terminal 1 or the press contact terminal 1 to which the electric wire 2 is pressed is artificially created in an atmosphere such as rain, high temperature, low temperature, or high humidity. 3 shows a test for knowing the weather resistance of the test object such as the pressure contact terminal 1 and the pressure contact terminal 1 to which the electric wire 2 is pressure-welded. For this reason, the weather resistance test described in this specification indicates a so-called atmospheric exposure test. In step S2, step S8, and step S10, for example, it is desirable to perform a temperature cycle test, a salt spray test, a heat resistance test, a cold resistance test, and the like defined by JIS (Japanese Industrial Standard) C 5432.

  The temperature cycle test is a test in which the above-described press contact terminal 1 and the press contact terminal 1 to which the electric wire 2 is pressed are left alternately in an atmosphere of −40 ° C. and an atmosphere of + 100 ° C. for 30 minutes. The salt spray test is a test in which salt water is continuously sprayed for 48 hours on the above-described press contact terminal 1 and the press contact terminal 1 to which the electric wire 2 is press contacted. The heat resistance test is a test in which the above-described press contact terminal 1 and the press contact terminal 1 to which the electric wire 2 is pressed are left in an atmosphere of + 85 ° C. for 96 hours. The cold resistance test is a test in which the press contact terminal 1 and the press contact terminal 1 to which the electric wire 2 is pressed are left in an atmosphere at −25 ° C. for 16 hours.

  According to the present embodiment, when the weather resistance test is performed on each of the plurality of press contact terminals 1 having different contact loads F before the press contact of the electric wire 2 and the electric wire 2 is press contacted, the core wires 3 of the press contact blades 11a and 11b A first lower limit value X of the contact load F at which rust is removed from the contacting end face 12 is determined. In addition, a weather resistance test is performed again on each of the plurality of press contact terminals 1 having different contact loads F after press contact of the electric wires 2, and the end face 12 and the core wire that are in contact with the core wire 3 of the press contact blades 11 a and 11 b are applied. 3, the second lower limit value Y of the contact load F that can prevent rust from occurring. A value satisfying the first lower limit value X and the second lower limit value Y is defined as a contact load F between the end faces 12 of the press contact blades 11 a and 11 b and the core wire 3.

  Since the contact load F is greater than or equal to both the first lower limit value X and the second lower limit value Y, even if rust occurs on the end faces 12 of the press contact blades 11a and 11b of the press contact terminal 1, the press contact blades 11a and 11b When the electric wire 2 is press-contacted, rust can be removed from between the core wire 3 and the press-contact blades 11a and 11b. For this reason, even if the end faces 12 of the press contact blades 11a and 11b corrode before the press contact of the electric wire 2, when the electric wire 2 is pressed, rust is removed from between the core wire 3 and the press contact blades 11a and 11b, and the press contact terminal 1 It is possible to prevent the electrical resistance value with the core wire 3 from increasing.

  Moreover, it can prevent that rust arises between the end surface 12 of the press contact blade 11a, 11b, and the core wire 3, after press-contacting the electric wire 2 to the press contact terminal 1. FIG. Even if the end faces 12 of the press contact blades 11a and 11b are to be corroded after the electric wire 2 is pressed, rust does not occur between the core wire 3 and the press contact blades 11a and 11b, and the electrical resistance value of the press contact terminal 1 to the core wire 3 Can be prevented from increasing.

  Therefore, the press contact blades 11a and 11b are plated by keeping the contact load F with the core wire 3 of the press contact blades 11a and 11b above both the first lower limit value X and the second lower limit value Y described above. Even if it contacts the core wire 3 on the surface where the base material 20 that is not exposed is exposed, it is possible to prevent the electrical resistance value with the core wire 3 from increasing due to secular change. For this reason, the reliability of the electrical connection with the core wire 3 can be ensured. Thus, even if it contacts with the core wire 3 in the surface where the preform | base_material 20 to which the press contact blade 11a, 11b is not plated is exposed, the press contact blade 11a, which can ensure the reliability of electrical connection with the core wire 3 An appropriate contact load F between 11b and the core wire 3 can be obtained.

  A first relationship A between an electrical resistance value between each press contact terminal 1 and the core wire 3 and a contact load F between the core wire 3 of each press contact terminal 1 is obtained, and a non-defective electrical product is obtained from the first relationship A. A value X of the contact load F that is equal to or less than the resistance value is obtained, and this value X is set as a first lower limit value X of the contact load F. For this reason, the first lower limit value X can be accurately obtained. Even if rust is generated on the end faces 12 of the press contact blades 11a and 11b of the press contact terminal 1, if the electric wire 2 is press contacted to the press contact blades 11a and 11b, the core wire 3 And rust can be reliably removed from between the contact blades 11a and 11b. Therefore, even if the press contact blades 11a and 11b are contacted with the core wire 3 on the exposed surface of the base material 20 on which the plating is not performed, the press contact blades 11a and 11b can ensure the reliability of the electrical connection with the core wire 3. An appropriate contact load F with the core wire 3 can be obtained reliably.

  A second relationship B between the electrical resistance value of each press contact terminal 1 on which the plating layer 21 is formed on the end face 12 and the core wire 3 and the contact load F between the core wire 3 of each press contact terminal 1 is obtained. Based on the relationship A and the second relationship B, the first lower limit value X is obtained. The first lower limit value X is the contact load F before the difference in electrical resistance value between the first relationship A and the second relationship B starts to occur as the contact load F is gradually reduced. Value X.

  When the first lower limit value X is obtained in this way, the electrical resistance value between the core wire 3 and the press contact terminal 1 can be maintained as in the case where the plating layer 21 is formed on the end face 12. Therefore, even if the press contact blades 11a and 11b are contacted with the core wire 3 on the exposed surface of the base material 20 on which the plating is not performed, the press contact blades 11a and 11b can ensure the reliability of the electrical connection with the core wire 3. An appropriate contact load F with the core wire 3 can be obtained more reliably.

  A third relationship C between the electrical resistance value of each press contact terminal 1 and the core wire 3 and the contact load F between the press contact terminal 1 and the core wire 3 is obtained, and a non-defective electrical product is obtained from the third relationship C. A value Y of the contact load F that is equal to or less than the resistance value is obtained, and this value Y is set as a second lower limit value Y of the contact load F. For this reason, the second lower limit value Y can be accurately obtained, and it is ensured that rust is generated between the end faces 12 of the press contact blades 11 a and 11 b and the core wire 3 after the electric wire 2 is press contacted to the press contact terminal 1. Can be prevented. Therefore, even if the press contact blades 11a and 11b are contacted with the core wire 3 on the exposed surface of the base material 20 on which the plating is not performed, the press contact blades 11a and 11b can ensure the reliability of the electrical connection with the core wire 3. An appropriate contact load F with the core wire 3 can be obtained reliably.

  A fourth relationship D between the electrical resistance value of each press contact terminal 1 on which the plating layer 21 is formed on the end face 12 and the core wire 3 and the contact load F between the core wire 3 of each press contact terminal 1 is obtained. Based on the relationship C and the fourth relationship D, the second lower limit value Y is obtained. The second lower limit value Y is the contact load F before the difference in electrical resistance value between the third relationship C and the fourth relationship D starts to occur as the contact load F is gradually reduced. Value Y.

  Thus, when the 2nd lower limit Y is calculated | required, the electrical resistance value between the core wire 3 and the press-contact terminal 1 can be maintained equivalent to what the plating layer 21 was formed in the end surface 12. FIG. Therefore, even if the press contact blades 11a and 11b are contacted with the core wire 3 on the exposed surface of the base material 20 on which the plating is not performed, the press contact blades 11a and 11b can ensure the reliability of the electrical connection with the core wire 3. An appropriate contact load F with the core wire 3 can be obtained more reliably.

  In the embodiment described above, the press contact terminal 1 for obtaining the first relation A and the press contact terminal 1 for obtaining the third relation C are separated. However, in the present invention, as shown in FIG. 12, the pressure contact terminal 1 used when obtaining the first relation A is used to obtain the third relation C after obtaining the first relation A. Also good. In FIG. 12, the same steps as those of the above-described embodiment are denoted by the same reference numerals and description thereof is omitted.

  In the case shown in FIG. 12, the process proceeds from step S6 to step S10. For this reason, in the case shown in FIG. 12, after obtaining the first lower limit value X, a weather resistance test is performed on the pressure contact terminal 1 that press-contacts the electric wire 2 used when obtaining the first lower limit value X. The second lower limit value Y is obtained. In this case, the first lower limit value X and the second lower limit value Y are obtained using the same press contact terminal 1. For this reason, resource saving can be achieved.

  In the present invention, in addition to the above-described temperature cycle test, salt spray test, heat resistance test and cold resistance test, various tests may be used as a weather resistance test.

  Moreover, in embodiment mentioned above, the electrical contact part 6 has shown the so-called female terminal metal fitting provided with the cylinder part 13 and the spring piece 14. In FIG. However, in the present invention, a so-called male terminal fitting in which the electrical contact portion 6 includes a plate-like or bar-like tab may be used as the press contact terminal.

  In addition, embodiment mentioned above only showed the typical form of this invention, and this invention is not limited to embodiment. That is, various modifications can be made without departing from the scope of the present invention.

It is explanatory drawing which shows the press-contact terminal by which the contact load was defined by the contact load evaluation method concerning one Embodiment of this invention, (a) is a perspective view of the press-contact terminal before an electric wire press-contacts, (b) is It is a perspective view of the press-contact terminal after an electric wire is press-contacted. It is sectional drawing which follows the II-II line | wire in FIG.1 (b). It is sectional drawing which follows the III-III line in FIG.1 (b). It is sectional drawing of the sheet metal which consists of a base material with which the press-contact terminal shown by FIG. 1 is shape | molded. It is sectional drawing of the sheet metal in which the plating layer was formed in both surfaces of the base material shown by FIG. It is a perspective view which shows the sheet metal shown by FIG. It is a perspective view which shows the state by which the punching process was given to the sheet metal shown by FIG. It is a perspective view which shows the state by which the bending process was given to the sheet metal shown by FIG. It is a flowchart which shows the process of determining the contact load of the press-contact terminal shown by FIG. It is explanatory drawing which shows the 1st relationship and 2nd relationship which are used by step S6 in FIG. It is explanatory drawing which shows the 3rd relationship and the 4th relationship which are used by step S13 in FIG. 10 is a modification of the flowchart shown in FIG. 9.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pressure contact terminal 2 Electric wire 3 Core wire 4 Covering part 11a, 11b Pressure contact blade 12 End surface 20 Base material A 1st relationship B 2nd relationship C 3rd relationship D 4th relationship X 1st lower limit Y 2nd lower limit

Claims (6)

In the method for evaluating the contact load of the press contact terminal to obtain an appropriate contact load with the press contact blade that contacts the core wire of the wire of the press contact terminal,
At the end surface of the press contact blade that contacts the core wire, the base material constituting the press contact terminal is exposed,
After producing a plurality of press contact terminals having different contact loads with the core wire and subjecting the plurality of press contact terminals to a weather resistance test, the wire is pressed against the press contact blade, and rust is generated from the end face of the press contact blade. Determining a first lower limit of the contact load to be removed;
After producing a plurality of pressure contact terminals having different contact loads with the core wire, and performing a weather resistance test on the plurality of pressure contact terminals, the wire is pressed against the pressure contact blades of the plurality of pressure contact terminals, and then the weather resistance test is performed. After applying, the second lower limit value of the contact load that can prevent the rust between the end face of the press contact blade and the core wire,
A method for evaluating a contact load of a press contact terminal, wherein a value satisfying the first lower limit value and the second lower limit value is set as the appropriate contact load.   When determining the first lower limit value of the contact load, an electrical resistance value between each press contact terminal in which the electric wire is press-contacted to the press contact blade and the core wire is measured, and the contact load and the electrical load are measured. A first relationship between the electrical resistance value and the electrical resistance value is determined to be a value equal to or lower than the electrical resistance value between the press contact terminal and the core wire, which is regarded as a non-defective product. 2. The method for evaluating a contact load of a press contact terminal according to claim 1, wherein this value is set as the first lower limit value. When determining the first lower limit of the contact load,
A plurality of press contact terminals having a plating layer formed on the end surface and having different contact loads with the core wire are subjected to a weather resistance test, and then the wire is pressed against the press contact blade. , Measuring an electrical resistance value between each press contact terminal and the core wire, and obtaining a second relationship between the contact load and the electrical resistance value,
The method for evaluating a contact load of a press contact terminal according to claim 2, wherein the first lower limit value is obtained based on the first relationship and the second relationship.   When determining the second lower limit value of the contact load, an electrical test is performed between each core contact terminal and the core wire subjected to a weather resistance test and subjected to a weather resistance test by pressing the wire against the press contact blade. A resistance value is measured to determine a third relationship between the contact load and the electrical resistance value. From the third relationship, between the press contact terminal and the core wire, the electrical resistance value is regarded as a good product. 2. The method for evaluating a contact load of a press contact terminal according to claim 1, wherein a value that is equal to or less than the electrical resistance value is obtained and the value is set as the second lower limit value. When obtaining the second lower limit of the contact load,
A plurality of press contact terminals having a plating layer formed on the end face and having different contact loads are manufactured, subjected to a weather resistance test, an electric wire is press-contacted to the plurality of press contact terminals, and the weather resistance test is performed. And measuring the electrical resistance value between the core wire and determining a fourth relationship between the contact load and the electrical resistance value,
The method for evaluating a contact load of a press contact terminal according to claim 4, wherein the second lower limit value is obtained based on the third relationship and the fourth relationship.   After obtaining the first lower limit value, a weather resistance test is performed on the pressure contact terminal that is press-contacted with the electric wire used when the first lower limit value is obtained, and the second lower limit value is obtained. The method for evaluating a contact load of a press contact terminal according to any one of claims 1 to 5.

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