KR20150008371A - Commutator material, method for manufacturing same, and micromotor using same - Google Patents

Abstract

A silver or silver alloy is coated on the entire surface or a part of the conductive base material and the surface of the silver or silver alloy is coated with gold or a gold alloy. After the silver or silver alloy is coated on the conductive base, (Reduced surface machining) is performed, and then a stripe-shaped gold or gold alloy is coated.

Description

Technical Field [0001] The present invention relates to a commutator material, a method of manufacturing the commutator material, a micromotor using the commutator material, and a micromotor using the commutator material,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrical contact material and a manufacturing method thereof, and more particularly, to an electrical contact material having excellent sliding characteristics, a manufacturing method thereof, and a micromotor having the electrical contact.

Micromotors are widely used for many applications such as sound devices, home appliances, mobile phones, cameras, and automobiles. The service life of the motor is determined by the durability of the commutator and the brush, which are members for energizing the motor coil. As the member, a material excellent in abrasion resistance, arc resistance, electrical connectivity, conductivity (conductivity) and strength is required, and in general, Ag alloy-coated Cu alloy baths are widely used. These materials are high-performance conductors that combine the abrasion resistance, arc resistance, electrical connectivity, and strength and conductivity of a Cu alloy possessed by the Ag alloy.

Since the brush material requires stable contact pressure, abrasion resistance, and low contact resistance, a Cu alloy for a spring having a plate thickness of about 0.03 to 0.1 mm and a Ag-Pd Alloy.

The Cu alloy base material used as the material for the commutator is a pure Cu-based, Cu-Sn-based or Cu-Sn-based alloy having a plate thickness of 0.1 to 0.3 mm. Examples of the Ag alloy include Ag-Mg, Ag- There are many systems. The coating of the Ag alloy is generally made of an inlay material coated only on a portion in contact with the brush, and the covering thickness is usually 20 to 100 mu m.

The brush material and the manufacturing method of the commutator material are carried out by compounding the Ag alloy tape with a so-called clad such as hot-press, cold-press, seam welding on the Cu alloy base material.

The brush material and the commutator material which have been used so far have various problems as described below.

(1) Precious metals such as Ag or Pd are expensive because of their large covering ratio.

(2) The manufacturing cost is high because it is manufactured by the cladding method.

(3) Because the clad is manufactured by annealing and rolling repeatedly, a machined strained layer is formed on the surface of the Ag alloy, and the arc resistance is poor, resulting in faster wear of the commutator and the brush, .

(4) Since the clad is manufactured by repeating annealing and rolling, alloy components other than Ag are concentrated on the surface of the Ag alloy, the initial contact resistance is high, and the corrosion resistance is poor.

(5) Substrates are exposed at portions other than the Ag alloy portion and the solder plating portion. The Cu alloy substrate has poor corrosion resistance, so that the contact portion is contaminated due to discoloration or creep phenomenon of corrosion products. do.

In order to solve these problems, development of an Ag alloy composition or coating of Au and Au alloy on an Ag alloy film has been carried out. However, only some problems have been solved and a comprehensive improvement is required.

Japanese Patent Application No. 58-218782 and Japanese Patent Application No. 58-218783 propose a contact material for a commutator and a brush material for a sliding contact in which a three-layer film is formed on a Cu alloy substrate. Either one of Cr, Ni, Ni alloy and Re has a thickness of 0.1 to 10 탆, the second layer has a thickness of 0.1 to 10 탆, and the third layer is made of Au, Ag And Au-Ag is a coating having a thickness of 0.1 to 10 mu m. When this material is used for a commutator or a brush and a conventional material is used for a counterpart, the above- The improvement of the motor life can not be greatly improved due to the influence of corrosion resistance. In addition, when the proposed materials are combined with each other by a micromotor, since the surfaces of both the commutator and the brush are made of Au, Ag, and Au-Ag alloy soft, adhesion wear occurs at the contact portion immediately after the motor is started , The conventional motor has a short life span due to the combination of the clad materials, and the problem can not be solved.

Japanese Patent No. 4520191 proposes a material in which a noble metal plating is formed over a predetermined length on a part of the commutator element base material. (Silver), Ag + Se (selenium), Ag + Se + Sb (antimony), Au (gold), Au + Co (cobalt), Pd (palladium) and Pd + Ni (nickel) are used for the noble metal plating. It is also described that the Ag layer may be formed by plating Au with two layers of Ag or Pd on the Ag layer, and then heat-treating the two layers to diffuse the two layers.

When the noble metal is coated in a stripe shape by plating, the plating film is inexpensive compared with the clad. However, since the plating film has a dense structure and a large internal stress, adhesion wear occurs when sliding the brush with the noble metal, And the motor life can not be obtained as much as expected.

In addition, since the stripe plating is performed in the product width, the plating processing cost is relatively expensive.

The inventor of the present invention has also proposed a technique in which an intermediate layer made of any one of nickel or an alloy thereof, cobalt or cobalt alloy, copper or a copper alloy is formed on a base body, and a palladium or palladium alloy, rhodium or rhodium alloy A ruthenium or ruthenium alloy, a silver or a silver alloy, or a gold or a gold alloy is formed on the outermost surface layer of the contact layer, wherein the outermost layer is formed on a part of the base surface, It is possible to provide a contact material for a motor in which contact failure is less likely to occur. Since this example shows a cold worked surface, the surface roughness is strongly influenced by the roll roughness of the rolling mill, and the lubricating oil is rolled by the rolling, thereby lowering the surface cleanliness. As a result, It has been found that there is a possibility of contamination by impurities in the test. Further, it was found that when the bending process was performed after the cold working, cracks sometimes occurred in some surface layers. For this reason, it is necessary to find the optimum condition of the reduction surface processing (reduction surface processing), and a method of increasing the surface cleanliness is required.

Further, it has been found that when silver or silver alloy is formed on the outermost layer, it tends to combine with sulfur to change color to black during motor sliding or stopping, and to increase the contact resistance. This is because grease around the commutator or a sulfur component in the atmosphere comes into contact with the silver or silver alloy, and it is also required to satisfy at the same time the improvement of the corrosion resistance.

Japanese Patent Application No. 58-218782 Japanese Patent Application No. 58-218783 Japanese Patent No. 4520191 Japanese Laid-Open Patent Publication No. 2010-146925

TECHNICAL FIELD The present invention relates to a commutator material for a motor formed by a conventionally used commutator material produced by cladding and by plating, and a commutator material having a specific plated film constitution, And to improve the life of the motor. In addition, the present inventors have studied to find a method of maximizing the effect while examining the optimum conditions of the reduction processing.

An object of the present invention is achieved by the following means.

(1) Electroconductive material A silver or silver alloy is coated on the entire surface or a part of the substrate and a metal such as gold, gold alloy, palladium, palladium alloy, platinum, platinum alloy A silver or a silver alloy is coated on the conductive base material, and then the surface is subjected to reduction processing. Thereafter, the material is partially coated with gold, gold alloy, palladium, palladium alloy, platinum , A platinum alloy, a rhodium alloy, and a rhodium alloy.

(2) The commutator material according to (1), wherein at least one of nickel, nickel alloy, cobalt or cobalt alloy is coated between the conductive base and the silver or silver alloy intermediate layer.

(3) The reduction of the surface of the conductive base after covering the entire surface or a part of the base with a silver or silver alloy is carried out by a rolling machine using a work roll having an arithmetic mean roughness (Ra) The commutator material according to (1) or (2).

(4) A silver or silver alloy is plated on the whole or a part of the conductive base, and then a reduction process is performed with a rolling machine using a work roll having an arithmetic mean roughness (Ra) of 0.2 mu m or less on the roll surface, Wherein the outermost layer is formed by plating any one of gold, gold alloy, palladium, palladium alloy, platinum, platinum alloy, rhodium and rhodium alloy.

(5) A micromotor according to any one of (1) to (3), wherein the commutator material is used in a commutator.

In the present invention, when covering the entire surface or part of the conductive base with the silver or silver alloy, the part is the minimum necessary width to contact the brush of the micromotor and is generally about 1 to 10 mm. Further, the amplitude of the commutator material is as large as 8 to 30 mm, and a portion of 10 to 30% of the amplitude is covered with stripe-shaped silver or silver alloy.

As described above, the commutator material of the present invention can drastically reduce the amount of noble metal used compared with conventional clad materials, and can also be manufactured by the plating method, so that the cost is greatly reduced, Effect. In addition, it is possible to improve the cleanliness of the reduction surface and to provide a commutator material for motors with less surface contamination, and to optimize the reduction processing conditions, thereby further contributing to improvement in motor life. In addition, by forming a strong coating on the silver or silver alloy with sulphide discoloration, it is possible to provide a commutator material for a motor in which the contact resistance is hardly increased and a longer life is expected.

These and other features and advantages of the present invention will become more apparent from the following description and accompanying drawings.

1 is a schematic cross-sectional view showing a preferred configuration example of the commutator material of the present invention.

The commutator material of the present invention can be obtained by coating a silver or silver alloy on the whole or part of a conductive base and further coating a surface of the silver or silver alloy with gold or a metal such as gold alloy, palladium, palladium alloy, platinum, platinum alloy, rhodium, rhodium alloy A silver alloy or a silver alloy is coated on the conductive base material and thereafter a reduction process is performed. Thereafter, a stripe-like gold, gold alloy, palladium, palladium alloy, platinum , A platinum alloy, a rhodium alloy, and a rhodium alloy. The conductive base is made of copper, nickel, iron or an alloy thereof, or a composite material in which a steel or an aluminum material is coated with copper or a copper alloy.

The configuration of the commutator material described above has the following configuration.

A layer 3 made of any one of nickel, a nickel alloy, a cobalt and a cobalt alloy serving as a base layer for plating (a lower layer) is formed on one surface (surface) of the base body 4, A silver or silver alloy layer 2 is formed with the silver or silver alloy layer 2 sandwiched therebetween, and a stripe-shaped gold, gold alloy, palladium, palladium alloy, platinum, platinum alloy, rhodium or rhodium alloy And the outermost surface layer 1 is formed.

As shown in Fig. 1 (2), a silver or silver alloy layer 2 is formed on one surface (surface) of a base body 4, and stripe gold or gold The outermost layer 1 made of any one of the alloy, palladium, palladium alloy, platinum, platinum alloy, rhodium and rhodium alloy is formed.

As shown in Fig. 1 (3), a silver or silver alloy layer 2 is formed on one surface (surface) of the base body 4, and stripe gold or gold And a silver or silver alloy layer (2) is formed on the back surface of the base (4), wherein the outermost layer (1) is made of any one of a metal, an alloy, a palladium alloy, a platinum alloy, a rhodium alloy, to be.

(4), a base layer 3 made of nickel, cobalt, or an alloy thereof serving as a base layer for plating is placed on one surface (surface) of the base body 4, The uppermost layer 1 formed of any one of stripe-shaped gold, gold alloy, palladium, palladium alloy, platinum, platinum alloy, rhodium and rhodium alloy, And an Ag or Ag alloy layer 2 is formed on the back surface of the base 4 with a layer 3 made of any one of nickel, nickel alloy, cobalt and cobalt alloy serving as a base layer for plating .

As the silver or silver alloy to be formed in the present invention, silver (Ag), silver-antimony (Sb) alloy, silver-selenium (Se) alloy, silver-antimony-selenium alloy and the like are applied. The thickness after the reduction processing is not particularly limited, but is, for example, in the range of 0.5 to 10 탆, preferably 2 to 5 탆. When the thickness is less than 0.5 탆, the life of the motor is extremely short, and if it is too thick, it is not preferable in terms of economy.

On the other hand, although the silver or silver alloy layer is formed on the entire surface in the drawing, further reduction in cost can be achieved by forming a silver or silver alloy layer only in a portion necessary for the motor commutator material. The shape is, for example, a stripe shape or a spot shape, and can be appropriately selected depending on the shape of the commutator member and the press interval. The surface (back surface) opposite to the functional surface required for the commutator material may be formed to have a thinner coating thickness than the functional surface if, for example, only the function of soldering is required.

As the outermost layer (1), for example, gold or a gold alloy, platinum or a platinum alloy, gold, a gold-cobalt alloy, a gold-nickel alloy, a gold- silver alloy, a platinum, a platinum-cobalt alloy, , Platinum-silver alloy, and gold-platinum alloy. The thickness is not particularly limited, but is preferably in the range of 0.005 to 0.5 mu m, more preferably 0.02 to 0.2 mu m. If it is thinner than 0.005 탆, brush material and adhesion wear are likely to occur and the life of the motor may decrease. If it is thicker than 0.5 탆, the economical effect is lost.

In addition, examples of the outermost layer (1) include palladium or palladium alloy, rhodium or rhodium alloy. As the palladium or palladium alloy, palladium, a palladium-nickel alloy or the like is applied. As the rhodium or rhodium alloy, rhodium, rhodium-nickel alloy or the like is applied. The thickness is not particularly limited, but is preferably in the range of 0.005 to 0.2 mu m, more preferably 0.01 to 0.1 mu m. If it is too thin, there is a high possibility that the life of the motor is lowered due to occurrence of brush material and adhesion wear, and when it is thicker than 0.2 탆, the effect becomes saturated and cracking of the plating occurs at the time of bending or press working It is easy to do and economically becomes ineffective.

The object of covering the outermost layer made of any one of gold, gold alloy, palladium, palladium alloy, platinum, platinum alloy, rhodium and rhodium alloy is that when one silver or silver alloy is used as a commutator as it is, Thereby causing adhesion wear. This is to prevent this. Particularly, when silver or silver alloy plating rises as a conventional example, adhesion wear is remarkable. The silver or silver alloy of the present invention has the characteristic that it is difficult to cause adhesion wear compared with the conventional product because it opens the internal stress. However, sufficient effect can not be obtained in this coating film, and the film, gold, A large effect is exhibited by the combination with the outermost layer of any one of palladium, palladium alloy, platinum, platinum alloy, rhodium and rhodium alloy.

As another effect, there is a case where silver or silver alloy is prevented from causing yellowing discoloration during motor sliding or stopping. This is to prevent an increase in contact resistance due to discoloration caused by the contact of the sulfur component in grease or atmospheric air with the silver or silver alloy around the commutator, and a longer service life is expected.

Further, in the present invention, since the silver or silver alloy layer is reduced and the internal stress of the silver or silver alloy is released, the surface cleanliness of the silver or silver alloy is insufficient. For example, It can be a factor for lowering the temperature. Therefore, by forming the outermost surface layer made of the above-described elements, the surface is also cleaned and the effect of improving the motor life can be obtained.

As the undercoat of the silver or silver alloy of the present invention, nickel or cobalt and alloys thereof may be coated in one or more layers. This base plating acts as a diffusion preventing barrier of the base material, and has an effect of preventing the base component from diffusing in the silver or silver alloy layer to reach the surface layer, thereby increasing the contact resistance. This thickness is not limited, but is carried out in the range of 0.1 to 2.0 탆.

The surface roughness (arithmetic mean roughness) of the rolling roll at that time is adjusted to be 0.2 탆 or less in terms of Ra, though the reduction processing performed after covering the silver or silver alloy is performed using a rolling mill.

The reduction of the surface area of the silver and silver alloy plating of the present invention can be achieved by opening the internal stress of the silver and silver alloy plating and by reducing the surface roughness and by increasing the bonding force between the base material and the silver or silver alloy layer or between the base layer and the silver or silver alloy layer , And to improve adhesion. Although the reduction processing is performed by rolling, plastic deformation at the time of rolling and heat accompanying the reformation cause the silver and silver alloy films to be recrystallized to open the internal stress and change to a film which is hard to be adhered to wear. In addition, by reducing the surface roughness of the work roll used in the rolling process, the surface roughness of the silver and silver alloy can be reduced, and the effect of less occurrence of adhesion wear becomes manifested. Further, it is possible to improve the interfacial bonding force between the base material and the silver or silver alloy layer or between the base layer and the silver or silver alloy layer by the mechanical force and the plastic working force, and to provide a coating film with further excellent adhesion. The reduction ratio is preferably in the range of 1 to 80%, more preferably 5 to 50%. When the reduction processing rate is less than 1%, the recrystallization of silver and silver alloy is insufficient, and when it exceeds 80%, the effect becomes saturated. The surface roughness of the work roll of rolling is effective when Ra is not more than 0.2 mu m, preferably not more than 0.1 mu m.

A base layer made of any one of nickel, nickel alloy, cobalt and cobalt alloy is introduced into the entire surface or part of the conductive base of the present invention as required, and then silver or silver alloy is plated, and then the surface roughness Ra ) Is 0.2 탆 or less, and then subjected to a slitting process to a desired width as required, and thereafter partially striped, for example, in the form of stripe-shaped gold or gold alloy, or stripe-shaped palladium or Palladium alloy is plated for the purpose of improving the plate thickness precision of the silver or silver alloy plating material and reducing the processing cost. Partial plating of the outermost layer, for example, stripe-shaped plating made of any one of gold, gold alloy, palladium, palladium alloy, platinum, platinum alloy, rhodium and rhodium alloy can be performed by suitably adjusting the width of the stripe and its interval Although not particularly limited, the stripe width is the minimum necessary width to contact the brush of the micromotor, and is generally about 1 to 10 mm. The amplitude of the commutator material is as large as 8 to 30 mm, and 10 to 30% of the width is covered with stripe-shaped silver or silver alloy.

In addition, since the outermost layer made of any one of gold, gold alloy, palladium, palladium alloy, platinum, platinum alloy, rhodium and rhodium alloy is formed by the plating method, the deterioration of the surface cleanliness by the reduction processing can be restored, It is possible to eliminate the circle, so that it is possible to suppress the deterioration of the motor life.

However, in the plating of the product width, the plating thickness distribution is generated in the product width direction, and the plate thickness accuracy is deteriorated. When molding by the motor commutator, the outward roundness is greatly influenced, There arises a problem that the lifetime is shortened due to the vibration of the brush and the brush, the followability, mechanical and electrical noise are generated. This problem is remarkable when the plating thickness is 1 占 퐉 or more, and this problem is solved by the present invention.

By performing the reduction processing after the silver or silver alloy plating, the convex portions generated in the plating can be smoothed, and as a result, the plate thickness accuracy is improved. Further, it is possible to significantly reduce the plating processing ratio by performing silver or silver alloy plating at a wide width several times the product width and then slitting the product width.

Example

The present invention will be described in more detail on the basis of examples.

In the line continuously plated on the raw material, a plate width of 100 mm shown in Table 1 and a plate thickness of C14410 (gas) of various sizes were passed through, and electrolytic degreasing and pickling were pre-treated After that, plating was carried out and further rolling was performed. Thereafter, the strip was cut into a width of 30 mm with a slitter, and stripe plating was performed with gold, gold alloy, palladium, palladium alloy, platinum or rhodium with a width of 5 mm to obtain the commutator material of the present invention.

The above-mentioned commutator material was press-processed and provided in a micromotor to test the life of the motor. On the other hand, 0.07 mm thickness of a swan for a spring (manufactured by Yohlwha, C7701R-H) in which a plating thickness of 1 탆 was plated with Pd was used as the brush material.

The evaluation results are shown in Table 1.

Plating conditions are shown below.

[Ni plating]

_{Plating: Ni (SO 3 NH 2)} 2 · 4H 2 O 500g / ℓ, NiCl 2 30g / ℓ, H 3 BO 3 30g / ℓ, the plating conditions: current density of 5A / d㎡, temperature 50 ℃,

[Co plating]

Plating solution: 400 g / l of CoSO ₄ , 20 g / g of NaCl, 40 g / l of H ₃ BO ₄ , plating conditions: current density 5 A /

[Ag Strike plating]

Plating solution: AgCN 5 g / l, KCN 60 g / l, K ₂ CO ₃ 30 g / l, plating conditions: current density 2 A /

[Ag plating]

Plating solution: AgCN 50 g / l, KCN 100 g / l, K ₂ CO ₃ 30 g / l, plating conditions: current density 1 A /

[Ag-Sb alloy plating]

Plating liquid: AgCN 50g / ℓ, KCN 100g / ℓ, K 2 CO 3 30g / ℓ, KSb (C 4 H 2 O 6) · 1.5 H 2 O 10g / ℓ, the plating conditions: Current density 1A / d㎡, temperature 30 ° C,

[Ag-Se alloy plating]

A plating solution was prepared by dissolving 1 g of Ag-0.5% Se plating solution: 150 g / l KCN, 15 g / l K ₂ CO ₃ , 75 g / l KAg [CN] ₂ , 5 g / l Na ₂ O ₃ Se 5 H ₂ O, dm < 2 &

[Au plating]

Plating solution: 10 g / L of K [Au (CN) ₂ ], 30 g / L of KCN, 30 g / L of K ₂ CO _3, 30 g / L of KH ₂ PO ₄ , plating conditions: current density 0.5 A /

[Au-Co alloy plating]

15 g / l of K [Au (CN) ₂ ], 150 g / l of C ₆ H ₈ O ₇ , 180 g / l of K ₃ (C ₆ H ₅ O ₇ ) 揃 H ₂ O, 0.1 g of cobalt solution 0.0 > ml / l, < / RTI > piperazine 2.0 g / l, plating conditions: current density 1 A /

[Au-Ni alloy plating]

Plating _{solution: K [Au (CN) 2} ] 3g / ℓ, KCN 1g / ℓ, CoSO 4 3g / ℓ, C 6 H 8 O 7 150g / ℓ, K 3 (C 6 H 5 O 7) · H 2 O 100g / ℓ, Ni (SO ₃ NH ₂ ) ₂揃 4H ₂ O 90 g / l, plating conditions: current density 1 A / dm 2, temperature 50 캜,

[Pd plating]

Plating _{liquid: Pd (NH 3) 2 Cl} 2 45g / ℓ, NH 4 OH 90㎖ / ℓ, (NH 4) 2 SO 4 50g / ℓ, the plating conditions: Current density 1A / d㎡, temperature 30 ℃,

[Pd-Ni alloy plating: Pd / Ni (%) 80/20]

Plating _{liquid: Pd (NH 3) 2 Cl} 2 40g / ℓ, NiSO 4 45g / ℓ, NH 4 OH 90㎖ / ℓ, (NH 4) 2 SO 4 50g / ℓ, the plating conditions: Current density 1A / d㎡, temperature 30 ° C,

[Pt plating]

_{Plating: Pt (NO 2) 2 (} NH 3) 2 10g / ℓ, NaNO 2 10g / ℓ, NH 4 NO 3 100g / ℓ, NH 3 50㎖ / ℓ, the plating conditions: current density of 5A / d㎡, temperature 90 ° C,

[Rh plating]

Plating solution: ROHDEX (trade name, manufactured by Electroplating Engineers Ltd), plating condition: 1.3 A / dm 2, temperature: 50 캜.

[Motor test]

The thickness of the brush material is 0.07 mm in a swan (C7701R-H material) for a spring for Pd plated with a plating thickness of 1 탆, and the brush pressure of the brush (pressure or force applied by the commutator) is set to 2.0 g , 2.5 V, 0.2 A, and 2000 rpm. The lifetime of the commutator with respect to the coating thickness of Ag or Ag alloy from the motor stopping time was obtained from the following formula.

[Motor stopping time] ÷ [Ag plating thickness] = [Lifetime per coating thickness]

[Bending workability test]

In the obtained commutator element, when the bending radius R was bent 90 degrees from 2 mm, the presence or absence of cracks in the outermost surface layer was examined on the bending convex side. The results are shown in Table 1, in which bending cracks did not occur and the base material was not exposed.

[Sulfation test]

A sulfurization test (H ₂ S concentration 3 ppm, 40 ° C, 80% humidity) in accordance with JIS H8502 was performed for 24 hours. Thereafter, the rating index (RN) was evaluated with respect to the discoloration degree of the surface of the commutator element, and it was judged that the RN was 9 or more, and the corrosion resistance was excellent.

Inventive Examples 1 to 4 are the commutator materials of FIG. 1 (2), and the rolling processing rate is changed. Inventive Examples 5 to 7 are the commutator materials shown in Fig. 1 (2) and the thickness of the Ag plated layer of the intermediate layer is changed. Inventive Examples 8 to 11 are the commutator materials of Fig. 1 (2), and the work roll roughness of the rolling process is changed. In Inventive Examples 12 to 13, the Ag plating layer of Inventive Example 1 is an Ag alloy plating layer. Inventive Examples 14 to 15 are the commutator materials of (1) in FIG. Example 16 is the above-mentioned commutator material shown in Fig. 1 (1), wherein the ground layer is a lower Ni / upper Co layer. Inventive Examples 17 to 21 are obtained by changing the thickness of the AuCo alloy layer of the outermost layer plating with the commutator material shown in Fig. 1 (2). In Inventive Example 22, the uppermost layer plating is made of an AuNi alloy layer with the commutator material shown in Fig. 1 (2). In Inventive Example 23, the uppermost layer plating is made of the Au plating layer with the commutator material shown in Fig. 1 (2). Examples 24 to 28 are obtained by changing the thickness of the Pd or PdNi alloy layer of the outermost layer plating with the commutator material of FIG. 1 (2). Inventive Examples 29 to 32 are obtained by changing the thickness of the Pt layer of the outermost layer plating with the commutator material of Fig. 1 (2). Example 33 is the commutator material shown in Fig. 1 (2), and the uppermost layer plating is Rh layer.

Comparative Example 1 is a commutator material having the same structure as that of Inventive Example 1 except that the work roll roughness in the rolling process is 0.30 탆 and the outermost layer plating is not formed.

Comparative Example 2 is a commutator material having the same constitution as that of Comparative Example 1, except that a striped Au alloy layer of the outermost surface layer plating was formed on the Ag layer without performing the rolling process in Comparative Example 1.

Comparative Example 3 is a commutator material having the same constitution as Comparative Example 1 except that the stripe-shaped Pt layer of the outermost surface layer plating is formed on the Ag layer without performing the rolling process in Comparative Example 1.

Comparative Example 4 is a commutator material having the same constitution as that of Comparative Example 1, except that the rolling process is not performed in Comparative Example 1.

Comparative Example 5 is an AgCuNi clad C14410R and a commutator material having an AgCuNi thickness of 50 mu m.

[Table 1]

As can be seen from Table 1, the commutator material of the present invention can provide a commutator material for a motor having a long commutator life of the motor per an Ag layer thickness and excellent corrosion resistance. Further, it is found that the commutator material having an improved lifetime can be provided even if the thickness of the coating material is made thinner, which is at least two times higher than the motor lifetime per the Ag layer thickness of the clad material.

Naturally, it is preferable that the arithmetic average roughness Ra of the work roll surface is small. For example, in the case of the commutator material having the same structure as that of the inventive example 1, the lifetime per 1 m of the commutator Ag was 760 hr./μm, except that the arithmetic mean roughness (Ra) of the surface of the work roll was 0.25 μm. Therefore, by making the arithmetic mean roughness (Ra) of the surface of the work roll equal to or smaller than 0.20 mu m, which is equal to or larger than 900 hr / m, as in the case of the respective inventions, adhesion wear is further hardly generated, Respectively.

Further, according to the present invention, cracks in the surface layer can not be found even in the bending test, and the adhesion between the substrate and the surface layer is improved by introduction of the rolling process and optimization of the rolling conditions, and a state in which the bending cracking property is improved can see. It can be seen that the motor exhibits excellent characteristics in both of the commutator life, the bending workability and the corrosion resistance of these motors.

While the invention has been described in conjunction with the embodiments thereof, it is to be understood that the invention is not limited to the details of the description, nor is it intended to limit the scope of the invention to the extent that it is within the spirit and scope of the invention as defined in the appended claims. .

This application claims priority based on Japanese Patent Application No. 2011-243242, filed on November 7, 2011 in Japan, which is hereby incorporated by reference in its entirety.

1. The outermost layer of the stripe shape
2. Ag or Ag alloy layer
3. Base layer
4. Gas

Claims (5)

The surface of a conductive substrate is covered with a silver or silver alloy and the surface of the silver or silver alloy is coated with a metal such as gold, gold alloy, palladium, palladium alloy, platinum, platinum alloy, rhodium, (Outermost layer) made of any one of the rhodium alloy,
The conductive base material is coated with a silver or silver alloy and then subjected to a reduction machining process and then partly formed of any one of gold, gold alloy, palladium, palladium alloy, platinum, platinum alloy, rhodium and rhodium alloy And the outermost layer is coated. The method according to claim 1,
Wherein one or more of nickel, nickel alloy, cobalt or cobalt alloy is coated between the conductive base and the intermediate layer of the silver or silver alloy. 3. The method according to claim 1 or 2,
Characterized in that the reduced surface treatment after covering the whole or part of the conductive base with a silver or silver alloy is carried out by a rolling machine using a work roll having an arithmetic mean roughness (Ra) at the roll surface of 0.2 탆 or less Commutator material. A silver or silver alloy is plated on the whole or a part of the conductive base, and then the reduction processing is carried out by a rolling machine using a work roll having an arithmetic mean roughness (Ra) of not more than 0.2 탆 on the roll surface, , Gold alloy, palladium, palladium alloy, platinum, platinum alloy, rhodium, and rhodium alloy is plated to form an outermost layer. A micromotor using the commutator material according to any one of claims 1 to 3 as a commutator.

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