JP2006286604A - Metallic material for wiring connection fixture - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optimum metallic material for a wiring connection fixture which prevents occurrence of glows and growth of cuprous oxide, and suppresses heat generation. <P>SOLUTION: The metallic material for a wiring connection fixture has an average roughness Ra of ≤0.3 μm and a maximum roughness Rt of ≤2.0 μm. The ratio of the maximum roughness Rt to the average roughness Ra, and Rt/Ra is ≤10. The metallic material is preferably a metal excellent in strength and conduction, such as stainless steel, Ni alloy or copper alloy, which has a tensile strength of ≥500 MPa and a conductivity of ≥30% IACS. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a metal material for a wiring connection device in which at least one of the metal members of the wiring connection device is a copper alloy material, and more particularly to a metal material for a wiring connection device that can prevent the occurrence of glow and the growth of cuprous oxide. Is.

  Wiring connection devices are widely used for electrical connections such as electrical appliance outlets and lighting switches. A metal is generally used for the connecting portion, and electrical connection is made by contacting the metals. Conventionally, heat generation has been a problem in the contact portion. It has been found that a minute discharge (glow) is generated at the contact portion, which causes the growth of cuprous oxide to increase the contact resistance and generate heat.

  There has been proposed a copper alloy for a wiring connector that is less prone to proliferation of glow and cuprous oxide by reviewing the alloy components (see, for example, Patent Document 1).

JP 60-255944 A

  However, even if the alloy components were examined, it was not possible to prevent heat generation due to the occurrence of glow and the growth of cuprous oxide. An object of the present invention is to provide a metal material that can prevent the occurrence of glow and proliferation of cuprous oxide and is suitable for wiring connection devices such as electrical appliance outlets and lighting switches.

The present inventors have made a detailed study on the contact portion of the wiring connection device, found that there is a relationship between the roughness (roughness) of the material surface and the occurrence of glow, and further studies based on this knowledge, the present invention It came to complete.
That is, the present invention
(1) At least one of the metal members in the wiring connection between the metal members is a metal material for a wiring connection device in which copper or a copper alloy material is used, and the average roughness Ra of the surface of at least one connection portion of the metal members is A metal material for a wiring connector characterized by excellent anti-glow properties having a maximum roughness Rt of 2.0 μm or less, and (2) a ratio Rt between the average roughness Ra and the maximum roughness Rt. / Ra is 10 or less, and provides a metal material for a wiring connector according to (1), which has excellent glow resistance.

  The metal material for a wiring connector of the present invention limits the average roughness Ra and the maximum roughness Rt, and further limits the ratio of the average roughness Ra and the maximum roughness Rt, thereby generating glow and cuprous oxide. Propagation can be prevented, heat generation can be suppressed, and it is an optimal metal material for wiring connection devices.

  A preferred embodiment of the present invention will be described in detail. In the present invention, the definition of roughness follows JIS B 0601: 2001. That is, in the present invention, the average roughness Ra refers to the arithmetic average roughness of the JIS B 0601: 2001. Similarly, in the present invention, the maximum roughness Rt is the roughness curve of the JIS B 0601: 2001. It refers to the maximum cross-sectional height.

In the present invention, at least one of the metal members in the wiring connection between the metal members is copper or a copper alloy material.
In the present invention, the average roughness Ra of the surface of at least one connection part (contact point) of the metal member is 0.3 μm or less and the maximum roughness Rt is 2 μm or less, and any metal member has an average roughness Ra of It is preferable that it is 0.3 μm or less and the maximum roughness Rt is 2 μm or less.
In the present invention, the metal member having an average roughness Ra of 0.3 μm or less and a maximum roughness Rt of 2 μm or less is a copper or copper alloy material, and a metal material that is not a copper or copper alloy material (for example, , Ni alloy material).
The reason why the average roughness Ra is 0.3 μm or less and the maximum roughness Rt is 2 μm or less is that the occurrence of glow can be remarkably reduced.
Roughness is one of the guidelines indicating the unevenness of the material surface, and it is considered that the voltage applied to the tip of the unevenness is concentrated to cause glow discharge.
In the present invention, when the average roughness Ra exceeds 0.3 μm, glow discharge tends to occur. Preferably it is 0.2 micrometer or less.
Further, when the maximum roughness Ra exceeds 2 μm, glow discharge is likely to occur. Preferably it is 1 micrometer or less.
The average roughness Ra and the maximum roughness Rt are preferably as small as possible.

In the present invention, the ratio Rt / Ra between the maximum roughness Rt and the average roughness Ra is preferably 10 or less.
The reason why the ratio Rt / Ra between the maximum roughness Rt and the average roughness Ra is 10 or less is that the generation of glow can be further reduced. When Rt / Ra exceeds 10, it is considered that there is a site with locally large irregularities, and glow discharge is likely to occur at that site.
In the present invention, Rt / Ra is preferably 5 or less. In addition, the smaller Rt / Ra is more preferable.

  Since the metal for wiring connection devices of the present invention is required to have contact pressure and electrical conductivity at a contact point, a metal having excellent strength and conductivity is generally used. Among them, stainless steel, Ni alloy, and copper alloy are preferable because they are excellent in strength and conductivity. More preferably, the tensile strength is 500 MPa or more, and the conductivity is 30% IACS or more.

As a more preferred example of the above,
(1) Sn is 0.1 to 10 mass%, P is 0.001 to 0.5 mass%, and the balance is a copper alloy composed of copper and inevitable impurities,
(2) a copper alloy comprising 0.1 to 1.0 mass% of Cr, 0.05 to 5 mass% of at least one element of Sn or Zn, and the balance of copper and inevitable impurities;
(3) 1.0 to 5.0 mass% of Ni, 0.3 to 1.3 mass% of Si, 0.05 to 5.0 mass% in total of at least one element of Mg, Sn, and Zn, with the balance being copper And a copper alloy composed of unavoidable impurities, or (4) a copper alloy composed of 0.5 to 3.0 mass% Fe, 0.1 to 1.0 mass% P, and the balance consisting of copper and unavoidable impurities.

  The metal material for a wiring connector according to the present invention is repeatedly manufactured by casting, hot rolling, cold rolling, heat treatment and the like by a general manufacturing method. Further, as a method for controlling the average roughness Ra and the maximum roughness Rt, the surface is washed with an acid / alkali or the like, and the roll roughness in the cold rolling process is changed.

  The present invention will be described below in more detail based on examples, but the present invention is not limited thereto.

  A plate material having a thickness of 0.15 to 0.25 mm made of a commercially available copper alloy and non-ferrous material was obtained, and the tensile strength, hardness, and conductivity were investigated. Tensile strength was measured according to JIS Z 2241 by cutting a JIS-5 test piece from the rolling parallel direction. The hardness was measured from the material surface according to JIS Z 2244 at a load of 100 g. The electrical conductivity was measured at a distance of 100 mm between terminals in accordance with JIS H 3200 by cutting out a test piece having a width of 10 mm and a length of 150 mm from the rolling parallel direction. The results are shown in Tables 1 and 2.

  The surface of the plate material is polished with various count emery paper (abrasive paper with SiC abrasive grains attached to the surface) in the same direction as the rolling direction (direction parallel to the rolling), and materials having different surface roughness It was created. That is, the plate material was fixed on a smooth surface plate, the count was increased in order from # 230 emery paper and polished 30 times with 8 stages of emery paper up to # 4000, and then the surface was washed. It was judged that the cuprous oxide on the surface layer was removed by the polishing, and the evaluation described later was performed.

  The surface roughness was measured according to JIS H 3406. The stylus was scanned 4 mm in the direction perpendicular to the rolling direction of the material or the direction polished with emery paper, and the measurement was repeated three times to obtain the average value.

These plate materials were evaluated for glow resistance and cuprous oxide growth characteristics.
FIG. 1 shows a schematic diagram of a measuring apparatus for glow resistance and cuprous oxide growth characteristics of the present invention.
The anti-glow property was evaluated as follows. That is, the copper wire 2 having a diameter of 2 mm is attached to the holder 1 with a load adder, the sample 3 of the present invention and the comparative example is placed on the sample holder 4 and brought into contact with the copper wire 2, and the slidac 8 and the variable resistor 6 is used to set the current flowing between the copper wire 2 and the sample 3 to 4A. Next, the sample holder 4 was vibrated by a vibrator 5, and the voltage waveform between the copper wire 2 and the sample 3 was observed by an oscilloscope 7. When glow (microdischarge) occurs between the copper wire 2 and the sample 3, the waveform of the oscilloscope 7 changes. Therefore, the frequency added until the waveform change occurs is defined as a glow resistance characteristic.

  Next, cuprous oxide growth characteristics were evaluated as follows. At the same time as the occurrence of the glow was confirmed, the vibration by the vibrator 5 was stopped, and the sample 3 was left for 60 minutes. Next, the sample 3 was taken out, the cuprous oxide produced on the surface of the sample 3 was collected, and the weight was measured. This weight is shown in Tables 3 to 7 as cuprous oxide growth. The results are shown in Tables 3-7.

As is apparent from Tables 3 to 7, the comparative example No. Nos. 85 to 120 have a large Ra or Rt, so that they have inferior anti-glow properties and a large amount of cuprous oxide.
In contrast, no. It can be seen that the plate materials of the present invention shown in Nos. 1 to 84 are excellent in the anti-glow property and the growth amount of cuprous oxide is small.

It is a schematic diagram of the measuring apparatus of the glow-proof characteristic and cuprous oxide growth characteristic of this invention.

Explanation of symbols

1 Holder with load adder 2 Copper wire 3 Sample 4 Sample holder 5 Vibrator 6 Variable resistor 7 Oscilloscope 8 Slidac

Claims (2)

  In the wiring connection between the metal members, at least one of the metal members is a metal material for a wiring connection device in which copper or a copper alloy material is used, and the average roughness Ra of the surface of at least one connection portion of the metal member is 0.3 μm. Hereinafter, a metal material for a wiring connector having a maximum roughness Rt of 2.0 μm or less and excellent glow resistance. The metal material for a wiring connector according to claim 1, wherein the ratio Rt / Ra between the average roughness Ra and the maximum roughness Rt is 10 or less, and has excellent glow resistance.

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