JP5290812B2 - Crimp terminal for high strength thin wire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a crimp terminal capable of obtaining a required crimp strength by using the same crimp terminal material as a conventional one relative to a high strength small diameter wire having 0.45 mm or less of wire diameter and tensile strength higher than the tensile strength of the crimp terminal material. <P>SOLUTION: In this crimp terminal for crimping a wire barrel 3 to a high strength small diameter wire 6 having 0.45 mm or less of wire diameter and tensile strength higher than the tensile strength of the crimp terminal material, thickness T of both side wall parts 3a of the wire barrel 3 is 0.65 times or more, desirably 0.8 times or more of the wire diameter (d) of the high strength small diameter wire 6. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a crimp terminal that is used for a wire harness of an automobile, and is particularly crimped to a high-strength thin wire having a thin wire diameter and high tensile strength.

  An example of a conventional crimp terminal is shown in FIG. The crimp terminal 1 generally has a contact portion 2 with a counterpart terminal, a wire barrel 3 that is crimped to a conductor end of an electric wire, and an insulation barrel 4 that is crimped to an insulating coating end of the wire ( (See Patent Documents 1 and 2). A serration (groove) 5 is formed on the inner surface of the wire barrel 3 in order to increase the pressure bonding strength. The illustrated example is a case where the contact portion 2 is female, but the contact portion 2 may be male. The crimp terminal 1 is formed by punching or bending from one conductive metal plate.

  A conventional crimp terminal is formed of a metal plate (copper alloy plate) having higher tensile strength than an electric wire (copper stranded wire).

Japanese Utility Model Publication No. 5-72053 Japanese Utility Model Publication No. 6-36216

  Recently, the use of a high-strength thin wire (for example, Corson alloy wire) whose wire diameter is thin and whose tensile strength is higher than that of a copper wire has been studied due to the demand for lighter and thinner wire harnesses. The high-strength thin wire under investigation has a wire diameter of 0.45 mm or less and a tensile strength higher than that of a conventional crimp terminal material. As a result, when a conventional crimp terminal is crimped to a high-strength thin wire, the repulsive force of the high-strength thin wire is large and it is difficult to obtain sufficient crimp strength.

  In order to solve this problem, it is conceivable to use a crimp terminal formed of a metal plate having a tensile strength higher than that of a high-strength thin wire, but such a crimp terminal not only increases the cost but also crimps. Work becomes difficult.

  The object of the present invention is to use the same crimp terminal material as the conventional one for the high-strength thin wire whose wire diameter is 0.45 mm or less and whose tensile strength is higher than the tensile strength of the crimp terminal material. It is in providing the crimp terminal which can be obtained.

In order to achieve the above object, the crimp terminal for a high-strength thin wire according to the present invention has a wire diameter of 0.45 mm or less and a high-strength thin wire made of a copper alloy stranded wire having a higher tensile strength than a copper stranded wire . A crimp terminal for crimping a wire barrel, wherein a copper alloy plate having a tensile strength higher than that of the copper stranded wire and lower than that of the high-strength thin wire is used as a crimp terminal material , and at least on both side wall portions of the wire barrel. The thickness is 0.65 times or more the wire diameter of the high-strength thin-diameter wire.

  In the crimp terminal for high-strength thin wire according to the present invention, the thickness of at least both side walls of the wire barrel is preferably 0.8 times or more the wire diameter.

  Further, the crimp terminal for high-strength thin wire according to the present invention has an inner peripheral length of the bottom portion of the high-strength thin wire when the thickness of the bottom portion of the wire barrel is thinner than the thickness of both side wall portions. It is preferable to make it half or less.

  According to the present invention, the thickness of the both side walls of the wire barrel is 0.65 times or more, preferably 0.8 times or more the wire diameter of the high-strength thin-diameter wire, so that the wire barrel has a high-strength thin-diameter. Since the spring back of the wire barrel when crimped to the wire is reduced and the repulsive force of the high-strength thin wire can be suppressed, the crimp strength of the wire barrel crimping portion can be increased.

  In addition, when the thickness of the bottom of the wire barrel is thinner than the thickness of both side walls, the inner circumference of the thin bottom is made half or less of the outer circumference of the high-strength thin wire. The crimping strength of the crimping part can be ensured.

Sectional drawing of the wire barrel part which shows one Example of the crimp terminal for high intensity | strength thin wires which concerns on this invention. Sectional drawing of the wire barrel part which shows the other Example of the crimp terminal for high intensity | strength thin wires which concerns on this invention. (A) is sectional drawing which shows the state which crimped the conventional crimp terminal to the high intensity | strength thin wire, (B) is a sectional view which shows the state which crimped the crimp terminal which concerns on this invention to the high strength thin wire. The graph which shows the result of having measured the springback amount when crimping the conventional crimp terminal (normal terminal) and the crimp terminal of this invention to the high-strength thin wire, respectively. The graph which shows the result of having measured the crimping | compression-bonding intensity | strength of the crimping | compression-bonding part which crimped the conventional crimp terminal and the crimp terminal of this invention to the high-strength thin wire, respectively. The perspective view which shows an example of the conventional crimp terminal.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows an embodiment of a crimp terminal for high strength thin wire according to the present invention. The crimp terminal 1 is for crimping the wire barrel 3 to the high-strength thin wire 6.

The high-strength thin wire 6 is, for example, a stranded wire obtained by twisting seven Corson alloy strands, and the wire diameter (diameter) d is 0.45 mm or less (the cross-sectional area is 0.13 mm ² or less). As a material for the high-strength thin wire 6, in addition to the Corson alloy, an alloy (for example, Cu-2.3) containing a trace element (Zn, Sn, Mg, etc.) based on a Cu—Ni—Si alloy (Corson alloy) is used. Ni-0.55Si-0.15Sn-0.5Zn-0.1Mg alloy, Cu-3.75Ni-0.9Si-0.15Sn-0.5Zn-0.1Mg alloy), beryllium copper alloy (C1720W), or the like may be used.

  Such a high-strength thin wire 6 has a tensile strength higher than the tensile strength of the material of the crimp terminal 1 (for example, FAS680 (a copper alloy plate manufactured by Furukawa Electric Co., Ltd., the same as before)) It is difficult to be compressed and deformed even by crimping the barrel 3. Incidentally, the tensile strength of the material of the crimp terminal 1 is about 600 to 700 MPa, whereas the tensile strength of the high-strength thin wire 6 is 800 MPa or more. The high-strength thin wire 6 having a strand diameter of 0.31 mm made of Corson alloy is about 1200 MPa, where the tensile strength of the material of the crimp terminal 1 is the JIS No. 5 shape according to JISZ2201 for the material. These samples were measured according to JISZ2241. The tensile strength of the high-strength thin wire 6 was also measured according to JISZ2241.

  In the crimp terminal 1 of this embodiment, the thickness T of the both side walls 3a of the wire barrel 3 is 0.65 times or more, more preferably 0.8 times or more the wire diameter d of the high-strength thin wire 6. There is a feature in the point (the reason is described later). The thickness t of the bottom 3b of the wire barrel 3 is the same as that of a conventional crimp terminal. In addition, the plate | board thickness of the normal crimp terminal crimped | bonded to the electric wire with a wire diameter exceeding 0.45 mm is about 0.13-0.15 mm. On the other hand, the thickness T of the both side walls 3a of the wire barrel 3 of the crimp terminal 1 according to the present invention is set to 0.65 times or more of the wire diameter d when the wire diameter d is 0.31 mm, for example. 20 mm or more, more preferably 0.80 times or more of the wire diameter d, and 0.25 mm or more.

  FIG. 2 shows another embodiment of the crimp terminal for high-strength thin wire according to the present invention. In the crimp terminal 1, the thickness of the bottom 3 b of the wire barrel 3 is set to 0.65 times or more the wire diameter d, as is the thickness of the side walls 3 a. The rest is the same as the crimp terminal of Example 1.

  Thus, when the thickness T of the both side walls 3a of the wire barrel 3 is 0.65 times or more the wire diameter d of the high-strength thin wire 6, conventional crimping is lower than the high-strength thin wire. Even when a terminal material is used, the crimping strength can be improved. Such knowledge has been confirmed by the following experiment. That is, when a normal crimp terminal (plate thickness 0.15 mm) is crimped to a high-strength thin wire 6 having a wire diameter of 0.31 mm (see FIG. 3A), the thickness of both side walls of the wire barrel When crimping a 0.20mm crimp terminal (see Fig. 3B), the springback amount after crimping (when the crimping tool is released from the bottom dead center of the crimping tool during crimping, the wire barrel is The amount returned by swelling was measured, and the result as shown in FIG. 4 was obtained. According to FIG. 4, it can be seen that the springback amount is reduced by about 12% by increasing the thickness of the wire barrel 3. Since the amount of springback is reduced, the pressure acting between the high-strength thin wire and the wire barrel is increased, so that the crimping strength is improved.

  Actually, a crimp terminal with a normal plate thickness (plate thickness of 0.15 mm), a crimp terminal with a normal plate thickness of +0.05 mm (plate thickness of 0.20 mm), and a crimp terminal with a normal plate thickness of +0.10 mm (plate thickness of 0.2 mm). The results of measuring the “crimp strength” by crimping three types of crimp terminals (25 mm) to a high-strength thin wire having a wire diameter of 0.31 mm are as shown in FIG. The “crimping strength” is a force when the wire breaks or pulls out when the crimping terminal is fixed and the wire is pulled. According to FIG. 5, it can be seen that the pressure bonding strength increases as the thickness of the wire barrel increases. The effect is that the compression strength can be improved by about 3% at a normal plate thickness of +0.05 mm, and the compression strength can be improved by about 14% at a normal plate thickness of +0.10 mm. The crimping strength is required to be 50 N or more in consideration of the tensile force applied at the time of manufacturing the wire harness and when the wire harness is assembled in the automobile assembly process.

  From the above experimental results, when the wire diameter of the high-strength thin wire is 0.31 mm, the optimum lower limit for the thickness of both side walls of the wire barrel is normal crimp terminal thickness + 0.05 mm = 0.2 mm It was considered that when the wire diameter was 0.65 times or more, a compression strength of 50 N or more was obtained. Moreover, it can be seen that if the thickness of both side wall portions of the wire barrel is set to the normal crimp terminal thickness +0.10 mm = 0.25 mm, that is, 0.8 times or more of the wire diameter, higher crimp strength can be obtained. It was. In the experiment, a high-strength thin wire having a wire diameter of 0.31 mm was used. However, since the crimping strength is proportional to the cross-sectional area, it is clear that the same result can be obtained even when the wire diameter is different.

  As shown in FIG. 1, when the thickness t of the bottom 3b of the wire barrel 3 is thinner than the thickness T of both side walls 3a, the inner circumference of the bottom 3b is set to the outer circumference of the high-strength thin wire 6. It is preferable to make it half or less. This is due to the following reason. That is, if the inner peripheral length of the thin bottom portion 3b is set to half or less of the outer peripheral length of the high-strength thin wire 6, the wire barrel 3 is crimped to the high-strength thin wire 6 as shown in FIG. When this is done, the thickness of the corners P on both sides of the bottom of the crimping part is not reduced, and the same crimping strength as when the entire wire barrel 3 is thick can be secured. On the other hand, if the inner peripheral length of the thin bottom portion 3b is longer than half of the outer peripheral length of the high-strength thin wire 6, the thickness of the corner portions P on both sides of the bottom side of the press-bonded portion is reduced and the pressure-bonded portion is pressed. There is a possibility that the side wall portions 3a are easily opened and the pressure bonding strength is lowered.

1: Crimp terminal 2: Contact part 3: Wire barrel 3a: Side wall part 3b: Bottom part 4: Insulation barrel 5: Serration 6: High strength thin wire

Claims (3)

A crimp terminal for crimping a wire barrel to a high-strength thin wire made of a copper alloy stranded wire having a wire diameter of 0.45 mm or less and a tensile strength higher than that of a copper stranded wire. A copper alloy plate having high strength and lower tensile strength than the high-strength thin wire is used , and the thickness of at least both side walls of the wire barrel is 0.65 times or more the wire diameter of the high-strength thin wire. Crimp terminal for high-strength thin wire characterized by Wa at least both side wall thickness of the ear barrel claim 1 high-strength thin wire crimp terminal, wherein the set to 0.8 times the wire diameter of the high strength thin line.   3. The high strength according to claim 1 or 2, wherein the thickness of the bottom of the wire barrel is thinner than the thickness of both side walls, and the inner peripheral length of the bottom is less than half of the outer peripheral length of the high-strength thin wire. Crimp terminal for thin wire.

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