JP2010146925A - Contactor material for electric motor and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a contactor material for an electric motor which hardly generates contact obstacles, and a method of manufacturing the same. <P>SOLUTION: Concerning the contactor material for an electric motor, a middle layer 2 and the outermost surface layer 3 are arranged on a base body 1, and the outermost surface layer 3 is arranged on a part of the surface of the base body 1. Copper (oxygen-free copper, tough-pitch copper) or its alloy (brass, phosphor bronze, nickel silver, Corson alloy or the like), iron or its alloy (SUS, 42 alloy or the like) are suitably used as the base body 1, nickel or nickel alloy, cobalt or cobalt alloy, copper or its alloy are suitably used as the middle layer 2, and silver or its alloy, palladium or its alloy, rhodium or its alloy, and gold or its alloy are suitably used as the outermost surface layer 3. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a contact material for a motor and a manufacturing method thereof.

  A noble metal material may be used as a contact material for a motor. In recent years, cost reduction of contact materials for motors has been studied, and in addition to contact materials composed of precious metals or their alloys, investigations have been made on contact materials with precious metals on the surface. Yes.

  For example, it is known to provide a contact material for a motor with a clad material (see Patent Document 1). It has been proposed to provide a noble metal by plating (see Patent Document 2). In Patent Document 2, it is preferable to apply 0.2 to 5.0 μm of palladium (Pd) plating as a noble metal.

Japanese Patent No. 3299282 Japanese Patent Laid-Open No. 2005-051987

  However, in the technique of Patent Document 1, when the noble metal is provided by the clad, the noble metal layer becomes thick and the noble metal is disposed on the entire surface of the material, which tends to increase the cost.

Moreover, in the technique of patent document 2, when Pd is formed on the surface layer by a plating method, there is a problem that the corrosion resistance is deteriorated. In particular, when the Pd plating thickness is 2.0 μm or less, pinholes are likely to be generated. Moreover, when Pd is formed on the surface layer by a plating method, hydrogen is occluded together with Pd precipitation, and the Pd surface becomes very hard. It has been found that when press working is performed to make this material have a predetermined shape, the Pd plating is cracked to form a crack, and the crack reaches the base or base material, thereby deteriorating the corrosion resistance. Further, if treatment for hydrogen occluded in the Pd layer is not performed, cracks may occur when pressed, and contact resistance may increase due to the influence of corrosion products as well as energization, resulting in poor conduction.
Furthermore, Patent Document 2 describes that carbon is contained in the plating film, but contact resistance increases due to the adhesion of carbon (brown powder or black powder) to the surface of the Pd plating, and the contact point. The risk of failure increases.

  Therefore, an object of the present invention is to provide a contact material for a motor that is unlikely to cause a contact failure and a method for manufacturing the same.

That is, the present invention provides the following solutions.
(1) An intermediate layer made of nickel or an alloy thereof, cobalt or an alloy thereof, copper or an alloy thereof is formed on a substrate, and palladium or an alloy thereof, rhodium or an alloy thereof, ruthenium or an alloy thereof, silver is formed thereon. Or a contact material for a motor in which an outermost layer made of any one of an alloy thereof, gold or an alloy thereof is formed, and after the outermost layer is formed on a part of the surface of the substrate, cold rolling A contact material for a motor, which is processed.
(2) The contact material for motors according to (1), wherein the outermost layer is formed in a stripe shape or a spot shape.
(3) When the thickness of the outermost layer is A (unit: μm), the thickness B (unit: μm) of the outermost layer after cold rolling is A / 5 to A / 2. The contact material for motors according to (1) or (2) above, wherein
(4) The contact material for motors according to (3), wherein the outermost layer is made of silver or an alloy thereof, and the thickness A when the outermost layer is formed is 0.5 to 10 μm. .
(5) The outermost layer is made of palladium or an alloy thereof, rhodium or an alloy thereof, ruthenium or an alloy thereof, gold or an alloy thereof, and the thickness A when the outermost layer is formed is 0.2 to 3.0 μm. The contact material for a motor according to (3), wherein the contact material is for a motor.
(6) Cold rolling is performed in a state where the hydrogen storage amount in the outermost layer after the formation is 1% by mass or less, and the hydrogen storage amount in the outermost layer is 0.2% by mass or less. The contact material for a motor according to (4) or (5).
(7) The contact material for motor according to any one of (1) to (6), wherein the formation of the intermediate layer and the formation of the outermost layer are performed by plating. .
(8) A method for manufacturing the motor contact material according to any one of (1) to (7) above, wherein the outermost layer is formed, and then in a temperature range of 100 ° C to 300 ° C. By performing heat treatment for 1 second to 60 seconds, the hydrogen storage amount in the outermost layer after the formation is set to 1% by mass or less, and then cold rolling is performed. Production method.

  In the present invention, since the outermost layer is formed on a part of the surface of the substrate and then cold-rolled, the pinholes in the outermost layer disappear, and the motor has excellent corrosion resistance and wear resistance. Contact material can be obtained.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a cross-sectional view showing one embodiment of the present invention. In FIG. 1, 1 is a substrate, 2 is an intermediate layer, and 3 is an outermost layer. FIG. 1A shows a state when the outermost layer 3 is formed, and FIG. 1B shows a state after the cold rolling of the outermost layer 3.

  As the substrate 1, copper (oxygen-free copper, tough pitch copper) or an alloy thereof (brass, phosphor bronze, iron white, Corson alloy, etc.), iron or an alloy thereof (SUS, 42 alloy, etc.) is preferably used.

  As the intermediate layer 2, nickel or a nickel alloy, cobalt or a cobalt alloy, copper or an alloy thereof is preferably used.

  As the outermost layer 3, silver or an alloy thereof, palladium or an alloy thereof, rhodium or an alloy thereof, gold or an alloy thereof is preferably used.

It is preferable that the outermost layer 3 is formed to a thickness of A (μm), and then the thickness is set to B = A / 5 to A / 2 (μm) by cold rolling. When the outermost layer 3 is cold-rolled to have a thickness B of A / 2 (μm) or less, the effect of filling the pinhole is exhibited even when the outermost layer 3 is formed by plating. The corrosion of the conductive substrate 1 and the like is effectively suppressed. Also, by setting the thickness to A / 5 (μm) or more, the wear resistance is improved from the state after plating, and the risk of exposing the base metal due to wear due to long-term operation is reduced, and the contact resistance is increased. And the risk of poor continuity is reduced.
Further, since the metal of the outermost layer 3 is softer than the metal of the intermediate layer 2 and is directly subjected to processing, the rolling rate is set at a ratio of reducing the target film thickness, whereby the plating layer of the outermost layer 3 is set. Only possible to make it thinner.

  Lower costs can be achieved if the outermost layer 3 is partially provided like a stripe or spot rather than the entire surface.

  When the outermost layer 3 is silver or an alloy thereof, the thickness is preferably 0.5 to 10 μm. When the outermost layer 3 is made of palladium or an alloy thereof, rhodium or an alloy thereof, or gold or an alloy thereof, the thickness is preferably It is preferable that it is 0.2-3.0 micrometers.

  When the outermost layer 3 is made of either palladium or an alloy thereof, rhodium or an alloy thereof, or gold or an alloy thereof, the hydrogen storage amount is 1 mass by performing heat treatment in an atmosphere at a temperature of 100 to 300 ° C. for 1 to 60 seconds. % Or less is preferable.

  There is no particular restriction on the thickness of the intermediate layer 2, but if it is too thick, it will be easily cracked when bent, and conversely if it is too thin, the barrier effect of the outermost layer will be thin, preferably 0.1-2.0 μm, Preferably, the thickness is 0.15 to 1.0 μm. The intermediate layer 2 can be formed by plating.

  FIG. 2 shows another embodiment of the present invention. 2A shows a state in which the outermost layer 3 is provided in a stripe shape in the longitudinal direction of the metal material, and FIG. 2B shows a state in which the outermost layer 3 is provided in a spot shape. The portion provided with the outermost layer 3 in FIG. 2 is a portion used as a contact, and is processed so as to be a contact portion in a pressing process. FIG. 2 shows a state in which the outermost layer 3 has a single stripe or spot shape. However, the outermost layer 3 may have a multi-row stripe or spot shape. It does not have to be.

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

  Here, the brush-side material and commutator-side material of the motor are prepared, and the brush-side material is used as the material of the examples of the present invention (invention examples and comparative examples).

[Brush side material]
Base material: C7701R-H thickness 0.05mm x width 22mm
Process: Degreasing → Pickling → Whole surface intermediate layer plating 1.0μm → Outermost layer plating → (Heat treatment) → Rolling [commutator side material]
Base material: Copper alloy EFTEC-3-1 / 2H manufactured by Furukawa Electric Co., Ltd. Thickness 0.3 mm x Width 18 mm
Process: Degreasing → Pickling → Full-surface Ni plating 0.5 μm → Outermost layer Ag plating 4.0 μm (no rolling)

(Pretreatment conditions)
[Electrolytic degreasing]
Degreasing liquid: NaOH 60 g / liter Degreasing conditions: Current density 2.5 A / dm ² , temperature 60 ° C., degreasing time 60 seconds [pickling]
Pickling solution: 10% sulfuric acid pickling condition: 30 seconds immersion, room temperature (25 ° C)

(Interlayer plating conditions)
[Ni plating]
Plating solution: Ni (NH ₂ SO ₃ H) 500 g / liter, NiCl ₂ 30 g / liter, H ₃ BO ₃ 30 g / liter Plating condition: current density 15 A / dm ² , temperature 50 ° C.
[Co plating]
Plating solution: CoSO ₄ 400 g / liter, NaCl 20 g / liter, H ₃ BO ₄ 40 g / liter Plating condition: current density 5 A / dm ² , temperature 30 ° C.
[Cu plating]
Plating solution: CuSO ₄ .5H ₂ O 250 g / liter, H ₂ SO ₄ 50 g / liter, NaCl 0.1 g / liter Plating condition: current density 6 A / dm ² , temperature 40 ° C.

(Outermost layer plating conditions)
[Ag strike plating]
Plating solution: AgCN 5 g / liter, KCN 60 g / liter, K ₂ CO ₃ 30 g / liter Plating condition: current density 2 A / dm ² , temperature 30 ° C.
[Ag plating]
Plating solution: AgCN 50 g / liter, KCN 100 g / liter, K ₂ CO ₃ 30 g / liter Plating condition: current density 0.5-3 A / dm ² , temperature 30 ° C.
[Glossy Ag plating]
Plating solution: AgCN 5 g / liter, KCN 100 g / liter, K ₂ CO ₃ 30 g / liter, NaS ₂ O ₃ 1.58 g / liter Plating condition: current density 1 A / dm ² , temperature 30 ° C.
[Pd—Ni alloy plating: Pd / Ni (%) 80/20]
Plating solution: Pd (NH ₃ ) ₂ Cl ₂ 40 g / liter, NiSO ₄ 45 g / liter, NH ₄ OH 90 ml / liter, (NH ₄ ) ₂ SO ₄ 50 g / liter Plating condition: current density 1 A / dm ² , temperature 30 ° C
[Pd plating]
Plating solution: Pd (NH ₃ ) ₂ Cl ₂ 45 g / liter, NH ₄ OH 90 ml / liter, (NH ₄ ) ₂ SO ₄ 50 g / liter Plating condition: current density 1 A / dm ² , temperature 30 ° C.
[Au plating]
Plating solution: KAu (CN) ₂ 14.6 g / liter, C ₆ H ₈ O ₇ 150 g / liter, K ₂ C ₆ H ₄ O ₇ 180 g / liter, EDTA-Co (II) 3 g / liter, piperazine 2 g / liter Plating conditions: current density 1 A / dm ² , temperature 40 ° C.
[Ru plating]
Plating solution: RuNOCl ₃ · 5H ₂ O 10 g / liter, NH ₂ SO ₃ H 15 g / liter Plating condition: current density 1 A / dm ² , temperature 50 ° C.

(Heat treatment conditions)
Tubular furnace, nitrogen atmosphere, 100 ° C to 300 ° C, 1 second to 60 seconds

(Characteristic evaluation)
[Motor life measurement: wear resistance evaluation]
The obtained material was pressed into the shape of a commutator piece and a brush material, and incorporated into a small motor for evaluation.
A motor test was performed under the conditions of an applied voltage of 2.5 V, a load current of 0.1 A, and a rotation speed of 2000 rpm, and the motor stop time was measured. As for the stop time, if it continued to rotate even after 300 days (7200 hours) from the start of measurement, the device was stopped at that point and the characteristics were sufficiently satisfied.
[Evaluation of corrosion resistance and confirmation of cracking of outermost layer]
Evaluation was performed after cutting the obtained material to a length of 100 mm.
Mixed gas test: H ₂ S = 100 ppb, Cl ₂ = 20 ppb, NO ₂ = 200 ppb were mixed and put into a test machine for 24 hours in an air atmosphere at a temperature of 40 ° C. and a humidity of 80% RH. Thereafter, the contact resistance was measured by a four-terminal method (Ag probe R = 4 mm, load 100 mN, measurement number n = 10, and an average value was calculated). The higher the contact resistance value, the worse the corrosion resistance. Generally, a contact value of 10 mΩ or less is a practical level as a contact.
Moreover, about the outermost layer of the obtained material, observation was performed 450 times using the microscope (made by Keyence), and the presence or absence of the crack was confirmed. Table 1 shows the thickness of each layer of the brush-side material and the presence or absence of heat treatment, and Table 2 shows the evaluation results of each material in Table 1.

  As shown in Table 2, the materials of the examples of the present invention (Inventive Examples 1 to 21) all show excellent corrosion resistance and wear resistance, but the materials of the comparative example and the conventional example are resistant to corrosion or resistance. It was inferior to at least one of abrasion.

It is sectional drawing which shows one embodiment of this invention, Comprising: (a) shows the state at the time of formation of the outermost layer 3, (b) shows the state after the cold rolling process of the outermost layer 3. FIG. It is sectional drawing which shows the other embodiment of this invention, Comprising: (a) shows the state by which the outermost layer 3 was provided in stripe form in the longitudinal direction of a metal material, (b) shows the outermost layer 3 in spot shape. The state where it is provided is shown.

Explanation of symbols

1 substrate 2 intermediate layer 3 outermost layer

Claims (8)

  An intermediate layer made of nickel or an alloy thereof, cobalt or an alloy thereof, copper or an alloy thereof is formed on a substrate, and palladium or an alloy thereof, rhodium or an alloy thereof, ruthenium or an alloy thereof, silver or an alloy thereof is formed thereon. A contact material for a motor in which an outermost layer made of either gold or an alloy thereof is formed, and after the outermost layer is formed on a part of the surface of the substrate, cold rolling is performed. The contact material for motors characterized by being made.   The contact material for a motor according to claim 1, wherein the outermost layer is formed in a stripe shape or a spot shape.   When the thickness at the time of forming the outermost layer is A (unit: μm), the thickness B (unit: μm) of the outermost layer after cold rolling is A / 5 to A / 2. The contact material for motors according to claim 1 or 2.   4. The contact material for motor according to claim 3, wherein the outermost layer is made of silver or an alloy thereof, and the thickness A when the outermost layer is formed is 0.5 to 10 [mu] m.   The outermost layer is composed of palladium or an alloy thereof, rhodium or an alloy thereof, ruthenium or an alloy thereof, gold or an alloy thereof, and the thickness A when the outermost layer is formed is 0.2 to 3.0 μm. The contact material for a motor according to claim 3, wherein the contact material is a motor.   Cold rolling is performed in a state where the hydrogen storage amount in the outermost layer after the formation is 1% by mass or less, and the hydrogen storage amount in the outermost layer is 0.2% by mass or less. Item 6. The contact material for a motor according to claim 4 or 5.   The contact material for a motor according to any one of claims 1 to 6, wherein the intermediate layer and the outermost layer are formed by plating.   It is a method of manufacturing the contact material for motors of any one of Claims 1-7, Comprising: After forming the said outermost layer, it is 1 second-60 second in the temperature range of 100 to 300 degreeC. The manufacturing method of the contact material for motors characterized by performing the heat processing of, and making the hydrogen occlusion amount in the outermost layer after the said formation into 1 mass% or less, and performing cold rolling after that.

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