WO2018135162A1 - Copper graphite brush - Google Patents

Copper graphite brush Download PDF

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Publication number
WO2018135162A1
WO2018135162A1 PCT/JP2017/043752 JP2017043752W WO2018135162A1 WO 2018135162 A1 WO2018135162 A1 WO 2018135162A1 JP 2017043752 W JP2017043752 W JP 2017043752W WO 2018135162 A1 WO2018135162 A1 WO 2018135162A1
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Prior art keywords
mass
brush
copper
graphite
bending strength
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PCT/JP2017/043752
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French (fr)
Japanese (ja)
Inventor
加央理 赤瀬
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トライス株式会社
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Priority to JP2018563201A priority Critical patent/JPWO2018135162A1/en
Priority to CN201780071558.0A priority patent/CN109983140A/en
Publication of WO2018135162A1 publication Critical patent/WO2018135162A1/en

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F5/00—Manufacture of workpieces or articles from metallic powder characterised by the special shape of the product
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C1/00—Making non-ferrous alloys
    • C22C1/10—Alloys containing non-metals
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K13/00—Structural associations of current collectors with motors or generators, e.g. brush mounting plates or connections to windings; Disposition of current collectors in motors or generators; Arrangements for improving commutation

Definitions

  • This invention relates to a copper graphite brush.
  • the present invention relates to the improvement of the mechanical strength of a brush for a DC motor that is widely used as a sliding member for industrial machines, and particularly to the improvement of the bending strength.
  • a copper graphite brush having slidability and conductivity is used as a brush for a DC motor.
  • the graphite contained in the copper-graphite brush has an effect of improving the slidability when the sliding surface wears and forms a carbon film on the sliding surface when sliding on the counterpart material. Further, copper is excellent in conductivity, is moderately soft, can hardly damage the counterpart material, and can improve conductivity without impairing slidability.
  • the brush for the DC motor has the brush tip in contact with the sliding surface in a pressurized state inside the motor, so that pressure (load) is applied to the brush and the DC motor is used for a long time. There is concern about the occurrence of sliding failure due to the effect of the effect. For this reason, it is desirable that the brush for the DC motor has a high bending strength, and a brush capable of stably maintaining the high bending strength is required particularly in a high temperature environment.
  • Patent Document 1 JP2002-80922 describes graphite: 10 to 30 mass%, hexagonal boron nitride: 0.5 to 4 mass%, Ag: 0.2 to 1.5 mass%, and the balance Cu (64.5 to 89.3 mass%).
  • a quality brush is disclosed. In order to improve the bending strength, this brush has a skeleton structure of Cu phase extending in the direction intersecting the sliding surface, so the Cu ratio in the brush is increased, and the content of graphite responsible for slidability is 10-30 mass It has become smaller with%.
  • expensive hexagonal boron nitride and Ag are contained.
  • Patent Document 2 discloses blending a resin such as polyethylene, polypropylene, and polystyrene into a copper graphite brush and thermally decomposing the resin during firing.
  • a certain degree of bending strength 13 MPa is obtained by bonding graphite particles with thermally decomposed resin.
  • higher bending strength may be required.
  • the conductivity of the surface of the sliding part may deteriorate.
  • An object of the present invention is to obtain a copper graphite brush having a stable bending strength over a long period of time in a high temperature environment in a copper graphite brush used for a DC motor.
  • This invention is a copper-graphite brush containing copper and graphite, characterized in that it contains a boron compound of 0.1 mass% or more and 2.0 mass% or less in terms of B 2 O 3 as boron oxide or boric acid. .
  • the boron oxide is, for example, B 2 O 3 , but may include B 2 O 2 , B 4 O 3 , B 4 O 5 and the like.
  • Boric acid is, for example, H 3 BO 3 , HBO 2 , H 2 B 4 O 7 or the like. Boric acid easily changes to B 2 O 3 at 300 ° C. or higher, and boric acid may change to boron oxide by heating during firing.
  • B 2 O 3 is a typical boron oxide, but may be partially reduced during firing and may contain B 2 O 2 or the like.
  • boron oxide may absorb moisture and change into boric acid.
  • boron oxide and boric acid are substances that can change from each other, and there is no significance in distinguishing them.
  • Boron oxide, boric acid and the like may contain impurities such as Na ions.
  • the boron compound content is determined in terms of B 2 O 3 .
  • H 3 BO 3 has a melting point of 184 ° C.
  • H 2 B 4 O 7 has a melting point of 140 ° C.
  • B 2 O 3 having a higher melting point has a melting point of 577 ° C.
  • the boron compound melts during firing and acts as a kind of binder, which improves the bending strength of the copper graphite brush.
  • boron oxide and boric acid are collectively referred to as a boron compound, and the content of the boron compound is shown in terms of B 2 O 3 .
  • the copper graphite brush is sometimes simply called a brush.
  • the content of the boron compound in the brush is 0.1 mass% or more and 2.0 mass% or less, the bending strength after firing is high, and the change in bending strength is small even when used at high temperatures.
  • the boron compound content is 3.0 mass% or more, the brush surface is uneven, but when it is 2.0 mass% or less, the appearance is not a problem. 3 shows the brush surface when the boron compound content is 0.8 mass%, FIG.
  • FIG. 4 shows the brush surface when the boron compound content is 3 mass%
  • FIG. 5 shows the boron compound content is 7 mass%.
  • the brush surface is shown.
  • corrugation considered to originate in a boron compound is seen on the brush surface.
  • the sliding action derived from graphite is enhanced, and expensive lubricants such as hexagonal boron nitride and Ag are not required.
  • the kind of graphite is arbitrary, such as artificial graphite and natural graphite.
  • amorphous carbon derived from thermosetting resins such as phenol resins or thermoplastic resins is not included in graphite.
  • the brush may contain impurities such as amorphous carbon such as coke, solid lubricant such as molybdenum disulfide and tungsten disulfide, other additives, and ash.
  • the graphite content is less than 35 mass%, the sliding action is deteriorated, which is not desirable. On the other hand, if the graphite content exceeds 80 mass%, the amount of electrolytic copper powder may be reduced and conductivity may be deteriorated. Copper and graphite are the main components of the brush, and the copper content is, for example, 15 mass% or more and 63 mass% or less.
  • Copper is not limited to pure copper but may be brass or the like as long as it contains a copper element.
  • the electrolytic copper powder has a dendritic shape, and the copper powder is entangled with each other to obtain high conductivity.
  • the particle size of the copper powder is not particularly limited, but those having a particle size of 10 ⁇ m or more and 100 ⁇ m or less are used. Note that the particle shape of the electrolytic copper powder is not lost even after firing.
  • the content of the boron compound is preferably 0.1 mass% or more and 1.0 mass% or less, and most preferably 0.5 mass% or more and 1.0 mass% or less in terms of B 2 O 3 .
  • the content of the boron compound is 0.5 mass% or more, the bending strength is high and the change with time at high temperature is also small.
  • the content of the boron compound is 2.0 mass%, the bending strength at a high temperature changes more greatly than the case where the bending strength is high but 1.0 mass% or less.
  • it is less than 0.1 mass% an effect will become small for the improvement of a bending strength, and if it exceeds 2.0 mass%, an external appearance will deteriorate.
  • the boron compound is present in the brush in the form of particles in principle. Note that this does not exclude that a part of the boron compound exists in a form other than the particulate form.
  • the boron compound since the boron compound was blended as a powder of boric acid or the like, the existence form after firing should be in the form of particles.
  • the boron compound particle grains which the distribution of a boron element and oxygen element correspond, and are independent of the distribution of a copper element exist in a brush. Since copper and graphite are in the form of particles in the brush, the copper, graphite, and boron compound are each present in the form of particles in the brush. *
  • a copper graphite brush having a high bending strength and a bending strength that hardly changes with time even at a high temperature can be obtained.
  • FIG. 1 of the brush embodiment of the copper-graphite brush 2 indicates, 4 in the sliding surface of the sliding partner 8 such as commutator, the brush 2 is provided with a lead wire 6, Pressure is applied toward the sliding surface 4 in the direction of the arrow in the figure.
  • the brush 2 may be a single layer, two layers, or three layers. In the case of multiple layers, it is sufficient that a predetermined amount of a boron compound is contained in any layer.
  • Phenol resin dissolved in methanol is mixed with natural scaly graphite, uniformly kneaded with a mixer, dried with a dryer, pulverized with an impact pulverizer, and sieved with an 80 mesh pass. Sieving with (198 ⁇ m pass sieve) to obtain resin-treated graphite powder.
  • Electrolytic copper powder (average particle size 40 ⁇ m), boric acid (H 3 BO 3 ) powder, and molybdenum disulfide are added to the resin-treated graphite powder, and mixed with a V-type mixer to obtain a blended powder. It was. H 3 BO 3 may be changed to other boric acid such as H 2 B 4 O 7 or may be changed to boron oxide such as B 2 O 3. The boron compound is blended as a powder.
  • Molybdenum disulfide may be replaced with other solid lubricants such as tungsten disulfide, and may contain other components.
  • the graphite content is 35 mass% or more from the viewpoint of lubricity, and accordingly, the Cu content is preferably 64 mass% or less, and the Cu content is 19 mass% or more from the viewpoint of conductivity, and accordingly the graphite content is included.
  • the amount is preferably 80 mass% or less.
  • the compounded powder is put into the mold from the hopper and molded at a pressure of 4 ⁇ 10 8 Pa (48 ⁇ 9800 N / cm 2 ) so as to embed the tip of the lead wire 6, and at 700 ° C. in a reducing atmosphere electric furnace Sintering was performed to obtain a brush having the composition shown in Table 1.
  • the firing temperature is preferably 600 ° C to 1000 ° C.
  • FIG. 2 shows an EPMA (Electron Probe Micro Analysis) image of the brush cut surface in Example 6.
  • the distribution of B element and the distribution of O element are almost the same, but not the distribution of Cu element. This indicates that boron exists in the form of particles as boron oxide or boric acid. This also corresponds to the incorporation of boron as boric acid (H 3 BO 3 ).
  • FIG. 3 is a photograph showing the brush surface of Example 4
  • FIG. 4 is a photograph showing the brush surface of Comparative Example 2
  • FIG. 5 is a photograph showing the brush surface of Comparative Example 4.
  • the brush in the photograph is a test piece prepared by the manufacturing method described in the above example, and the dimensions are 20 mm ⁇ 10 mm ⁇ 5 mm.
  • the boron content in terms of B 2 O 3 is 0.1 to 2 mass%
  • the brush surface is smooth and can be used as it is.
  • the comparative example where the boron content is 3 to 7 mass%, Possible lumps appear and the surface is uneven. And since this lump is easy to fall off during use of a brush, the comparative example whose boron content is 3 mass% or more is not practical.
  • the brush resistivity and the like were in a range where there was no practical problem.
  • the bending strength of the brush after firing and the bending strength after aging at 200 ° C. for 100 hours and after aging at 200 ° C. for 400 hours were measured.
  • the bending strength is a three-point bending strength.
  • Table 2 shows the evaluation results of the bending strength and the appearance of the brush. *
  • Table 2 shows the following.
  • the boron compound concentration in terms of B 2 O 3 is less than 0.1 mass%, the bending strength of the brush is insufficient. If it is 0.1 mass% or more and less than 0.5 mass%, the bending strength is improved but slightly low. In the range of 0.5 mass% to 1.0 mass%, the bending strength is high, and the change with time in bending strength at high temperatures is small. If it is more than 1.0 mass% and not more than 2.0 mass%, the bending strength is high, but the change with time in the bending strength at a high temperature becomes slightly large. If it exceeds 2.0 mass%, it cannot be used due to poor appearance, and cracking may occur during the time-lapse test. For these reasons, the boron compound content is 0.1 mass% or more and 2.0 mass% or less, preferably 0.1 mass% or more and 1.0 mass% or less, and most preferably 0.5 mass% or more and 1.0 mass% or less.
  • the copper graphite brush for a DC motor according to the present invention has high bending strength and small change with time at high temperature, so that the characteristics can be maintained for a long time. For this reason, it can be suitably used for sliding members that are used for a long period of time at high temperatures, such as automobile motors, alternators and the like.

Abstract

This copper graphite brush contains, in an amount of 0.1-2.0 mass% expressed as B2O3, a boron compound in the form of boron oxide or boracic acid.

Description

銅黒鉛質ブラシCopper graphite brush
　この発明は銅黒鉛質ブラシに関する。 This invention relates to a copper graphite brush.
　本発明は、産業機械用の摺動部材として広く用いられているDCモータ用のブラシの機械的強度の改善に関し、特に曲げ強度の改善に関する。 The present invention relates to the improvement of the mechanical strength of a brush for a DC motor that is widely used as a sliding member for industrial machines, and particularly to the improvement of the bending strength.
　DCモータ用のブラシには、摺動性及び導電性を備える銅黒鉛ブラシが用いられている。銅黒鉛質ブラシに含まれる黒鉛は、相手材と摺接する際、摺動面が摩耗して摺接面にカーボン被膜を形成し、摺動性を向上させる効果がある。また、銅は導電性に優れ、かつ適度に柔らかく、相手材を傷付け難く摺動性を損なわずに導電性を向上させることができる。 A copper graphite brush having slidability and conductivity is used as a brush for a DC motor. The graphite contained in the copper-graphite brush has an effect of improving the slidability when the sliding surface wears and forms a carbon film on the sliding surface when sliding on the counterpart material. Further, copper is excellent in conductivity, is moderately soft, can hardly damage the counterpart material, and can improve conductivity without impairing slidability.
　前記、DCモータ用のブラシは、モータ内部においてブラシ先端面を加圧状態で摺動面に当接させるため、ブラシに加圧（負荷）が掛かりDCモータの使用が長期に亘ると加圧が及ぼす影響による摺動不良の発生が懸念される。このためDCモータ用のブラシは曲げ強度の高いものが望ましく、特に高温環境下で、高い曲げ強度が安定して維持されるブラシが必要になる。 The brush for the DC motor has the brush tip in contact with the sliding surface in a pressurized state inside the motor, so that pressure (load) is applied to the brush and the DC motor is used for a long time. There is concern about the occurrence of sliding failure due to the effect of the effect. For this reason, it is desirable that the brush for the DC motor has a high bending strength, and a brush capable of stably maintaining the high bending strength is required particularly in a high temperature environment.
　特許文献１（JP2002-80922）は、黒鉛：10～30mass%、六方晶窒化ホウ素：0.5～4mass%、Ag：0.2～1.5mass%、と残部のCu（64.5～89.3mass%）を含む銅黒鉛質ブラシを開示している。曲げ強度を向上させるため、このブラシは摺動面と交わる方向に伸びるCu相の骨格構造を有し、そのためブラシ中のCu比が大きくなり、摺動性を担う黒鉛の含有量は10～30mass%と小さくなっている。そして摺動性を補うために、高価な六方晶窒化ホウ素とAgを含有させている。 Patent Document 1 (JP2002-80922) describes graphite: 10 to 30 mass%, hexagonal boron nitride: 0.5 to 4 mass%, Ag: 0.2 to 1.5 mass%, and the balance Cu (64.5 to 89.3 mass%). A quality brush is disclosed. In order to improve the bending strength, this brush has a skeleton structure of Cu phase extending in the direction intersecting the sliding surface, so the Cu ratio in the brush is increased, and the content of graphite responsible for slidability is 10-30 mass It has become smaller with%. In order to supplement the slidability, expensive hexagonal boron nitride and Ag are contained.
　特許文献２（WO2007/096989）は、銅黒鉛質ブラシにポリエチレン、ポリプロピレン、ポリスチレン等の樹脂を配合し、焼成時に樹脂を熱分解することを開示している。そして熱分解した樹脂により黒鉛粒子を結合することにより、ある程度の曲げ強度（13MPa）を得ている。しかし実用上は、さらに高い曲げ強度が要求されることがある。また、非導電性の樹脂をブラシ中に多量に配合した場合、摺動部表面の導電性が悪化する場合がある。 Patent Document 2 (WO2007 / 096989) discloses blending a resin such as polyethylene, polypropylene, and polystyrene into a copper graphite brush and thermally decomposing the resin during firing. A certain degree of bending strength (13 MPa) is obtained by bonding graphite particles with thermally decomposed resin. However, in practice, higher bending strength may be required. Moreover, when a nonconductive resin is blended in a large amount in the brush, the conductivity of the surface of the sliding part may deteriorate.
JP2002-80922JP2002-80922 WO2007/096989WO2007 / 096989
　この発明の課題は、DCモータに使用する銅黒鉛質ブラシにおいて、高温環境下で長期に亘り安定した曲げ強度を有する銅黒鉛質ブラシを得ることにある。 An object of the present invention is to obtain a copper graphite brush having a stable bending strength over a long period of time in a high temperature environment in a copper graphite brush used for a DC motor.
　この発明は、銅と黒鉛とを含有する銅黒鉛質ブラシにおいて、B2O3換算で0.1mass%以上2.0mass%以下のホウ素化合物を、ホウ素酸化物あるいはホウ酸として含有することを特徴とする。 This invention is a copper-graphite brush containing copper and graphite, characterized in that it contains a boron compound of 0.1 mass% or more and 2.0 mass% or less in terms of B 2 O 3 as boron oxide or boric acid. .
　ホウ素酸化物は例えばB2O3であるが、B2O2,B4O3,B4O5などを含んでいても良い。またホウ酸は例えばH3BO3,HBO2,H2B4O7等である。ホウ酸は300℃以上ではB2O3に変化しやすく、焼成時の加熱によりホウ酸がホウ素酸化物に変化することがある。ホウ素酸化物ではB2O3が代表的であるが、焼成時に部分的な還元を受け、B2O2等が含まれていることがある。また銅黒鉛質ブラシを放置すると、ホウ素酸化物が吸湿してホウ酸に変化することがある。本発明において、ホウ素酸化物とホウ酸は互いに変化し得る物質であって、これらを区別する意義はない。ホウ素酸化物、ホウ酸などは、Naイオン等の不純物を含んでいても良い。そしてホウ素化合物の含有量は、B2O3に換算して定める。 The boron oxide is, for example, B 2 O 3 , but may include B 2 O 2 , B 4 O 3 , B 4 O 5 and the like. Boric acid is, for example, H 3 BO 3 , HBO 2 , H 2 B 4 O 7 or the like. Boric acid easily changes to B 2 O 3 at 300 ° C. or higher, and boric acid may change to boron oxide by heating during firing. B 2 O 3 is a typical boron oxide, but may be partially reduced during firing and may contain B 2 O 2 or the like. Moreover, when a copper graphite brush is left as it is, boron oxide may absorb moisture and change into boric acid. In the present invention, boron oxide and boric acid are substances that can change from each other, and there is no significance in distinguishing them. Boron oxide, boric acid and the like may contain impurities such as Na ions. The boron compound content is determined in terms of B 2 O 3 .
　H3BO3の融点は184℃、H2B4O7では140℃、これらに比べて高融点のB2O3でも融点は577℃である。ホウ素の化合物は焼成時に溶融して、一種のバインダとして作用し、このため銅黒鉛質ブラシの曲げ強度が向上する。なお300℃以下の低温焼成により銅黒鉛質ブラシを製造する場合、ホウ素化合物をホウ酸として配合することが好ましい。 H 3 BO 3 has a melting point of 184 ° C., H 2 B 4 O 7 has a melting point of 140 ° C., and B 2 O 3 having a higher melting point has a melting point of 577 ° C. The boron compound melts during firing and acts as a kind of binder, which improves the bending strength of the copper graphite brush. In addition, when manufacturing a copper graphite brush by low-temperature baking of 300 degrees C or less, it is preferable to mix | blend a boron compound as boric acid.
　以下、ホウ素酸化物とホウ酸とを総称してホウ素化合物と呼び、ホウ素化合物の含有量はB2O3に換算して示す。また銅黒鉛質ブラシを単にブラシと呼ぶことがある。表２に示すように、ブラシ中のホウ素化合物の含有量が0.1mass%以上2.0mass%以下で、焼成後の曲げ強度が高く、高温で使用しても曲げ強度の変化が小さくなる。さらにホウ素化合物の含有量が3.0mass%以上ではブラシ表面に凹凸が生じるが、2.0mass%以下では外観も問題がない。図３にホウ素化合物の含有量が0.8mass%の場合のブラシ表面を、図４にホウ素化合物の含有量が3mass%の場合のブラシ表面を、図５にホウ素化合物の含有量が7mass%の場合のブラシ表面を示す。図４，図５では、ホウ素化合物に由来すると考えられる凹凸がブラシ表面に見られる。 Hereinafter, boron oxide and boric acid are collectively referred to as a boron compound, and the content of the boron compound is shown in terms of B 2 O 3 . The copper graphite brush is sometimes simply called a brush. As shown in Table 2, the content of the boron compound in the brush is 0.1 mass% or more and 2.0 mass% or less, the bending strength after firing is high, and the change in bending strength is small even when used at high temperatures. Further, when the boron compound content is 3.0 mass% or more, the brush surface is uneven, but when it is 2.0 mass% or less, the appearance is not a problem. 3 shows the brush surface when the boron compound content is 0.8 mass%, FIG. 4 shows the brush surface when the boron compound content is 3 mass%, and FIG. 5 shows the boron compound content is 7 mass%. The brush surface is shown. In FIG. 4 and FIG. 5, the unevenness | corrugation considered to originate in a boron compound is seen on the brush surface.
　この発明では、黒鉛含有量を例えば35mass%以上80mass%以下とすることで、黒鉛に由来する摺動作用が高まり、六方晶窒化ホウ素、Ag等の高価な潤滑剤が不要になる。なお黒鉛の種類は、人造黒鉛、天然黒鉛等、任意である。またフェノール樹脂等の熱硬化性樹脂、あるいは熱可塑性樹脂等に由来する非晶質カーボンは、黒鉛に含めない。さらにブラシは、コークス等の不定形カーボン、二硫化モリブデン、二硫化タングステン等の固体潤滑剤、その他の添加物、及び灰分等の不純物を含んでいても良い。前記黒鉛含有量が35mass%を下回ると、摺動作用が悪化するため望ましくない。また前記黒鉛含有量が80mass%を上回ると、電解銅粉の量が小さくなり導電性が悪化する場合がある。銅と黒鉛がブラシの主成分で、銅含有量は例えば15mass%以上63mass%以下である。 In this invention, when the graphite content is, for example, 35 mass% or more and 80 mass% or less, the sliding action derived from graphite is enhanced, and expensive lubricants such as hexagonal boron nitride and Ag are not required. In addition, the kind of graphite is arbitrary, such as artificial graphite and natural graphite. In addition, amorphous carbon derived from thermosetting resins such as phenol resins or thermoplastic resins is not included in graphite. Further, the brush may contain impurities such as amorphous carbon such as coke, solid lubricant such as molybdenum disulfide and tungsten disulfide, other additives, and ash. If the graphite content is less than 35 mass%, the sliding action is deteriorated, which is not desirable. On the other hand, if the graphite content exceeds 80 mass%, the amount of electrolytic copper powder may be reduced and conductivity may be deteriorated. Copper and graphite are the main components of the brush, and the copper content is, for example, 15 mass% or more and 63 mass% or less.
　銅は純銅に限らず、黄銅などでも良く、銅元素を含んでいればよい。電解銅粉は樹状の形状で銅粉が互いに絡み合って高い導電性が得られる。また銅粉の粒度は、特に制限されないが、10μｍ以上、100μｍ以下のものが用いられる。なお焼成しても電解銅粉の粒子形状は失われない。 Copper is not limited to pure copper but may be brass or the like as long as it contains a copper element. The electrolytic copper powder has a dendritic shape, and the copper powder is entangled with each other to obtain high conductivity. The particle size of the copper powder is not particularly limited, but those having a particle size of 10 μm or more and 100 μm or less are used. Note that the particle shape of the electrolytic copper powder is not lost even after firing.
　ホウ素化合物の含有量は、好ましくはB2O3換算で0.1mass%以上1.0mass%以下とし、最も好ましくは0.5mass%以上1.0mass%以下とする。ホウ素化合物の含有量を0.5mass%以上とすると、曲げ強度が高く、高温下での経時変化も小さくなる。ホウ素化合物の含有量を2.0mass%とすると、曲げ強度は高いものの1.0mass%以下の場合よりも、高温での曲げ強度の経時変化が大きくなる。また、0.1mass%未満では曲げ強度の向上に効果が小さくなり、2.0mass%を上回ると外観が悪化してしまう。 The content of the boron compound is preferably 0.1 mass% or more and 1.0 mass% or less, and most preferably 0.5 mass% or more and 1.0 mass% or less in terms of B 2 O 3 . When the content of the boron compound is 0.5 mass% or more, the bending strength is high and the change with time at high temperature is also small. When the content of the boron compound is 2.0 mass%, the bending strength at a high temperature changes more greatly than the case where the bending strength is high but 1.0 mass% or less. Moreover, if it is less than 0.1 mass%, an effect will become small for the improvement of a bending strength, and if it exceeds 2.0 mass%, an external appearance will deteriorate.
　この発明では、ホウ素化合物は原則として粒子状の形態でブラシ中に存在する。なおこのことは、ホウ素化合物の一部が粒子状以外の形態で存在することを排除するものではない。実施例では、ホウ素化合物をホウ酸などの粉体として配合したので、焼成後の存在形態も粒子状のはずである。そして図２に示すように、ホウ素元素と酸素元素の分布が一致し、かつ銅元素の分布とは独立している、ホウ素化合物粒子がブラシ中に存在する。銅と黒鉛はブラシ中で粒子状をしているので、銅と黒鉛とホウ素化合物はブラシ中に各々粒子状の形態で存在する。　 In this invention, the boron compound is present in the brush in the form of particles in principle. Note that this does not exclude that a part of the boron compound exists in a form other than the particulate form. In the examples, since the boron compound was blended as a powder of boric acid or the like, the existence form after firing should be in the form of particles. And as shown in FIG. 2, the boron compound particle | grains which the distribution of a boron element and oxygen element correspond, and are independent of the distribution of a copper element exist in a brush. Since copper and graphite are in the form of particles in the brush, the copper, graphite, and boron compound are each present in the form of particles in the brush. *
　この発明では、曲げ強度が高く、高温でも曲げ強度が経時変化しにくい銅黒鉛質ブラシが得られる。 According to the present invention, a copper graphite brush having a high bending strength and a bending strength that hardly changes with time even at a high temperature can be obtained.
実施例の銅黒鉛質ブラシの側面図Side view of the copper graphite brush of the example ブラシ切断面のSEM像と、B,O,Cu元素のEPMA像とを示す写真Photograph showing SEM image of brush cut surface and EPMA image of B, O, Cu elements 実施例のブラシ表面（ホウ素化合物含有量が0.8mass%）を示す写真Photograph showing brush surface of Example (boron compound content is 0.8 mass%) 比較例のブラシ表面（ホウ素化合物含有量が3mass%）を示す写真Photo showing brush surface of comparative example (boron compound content is 3 mass%) 比較例のブラシ表面（ホウ素化合物含有量が7mass%）を示す写真Photograph showing brush surface of comparative example (boron compound content is 7 mass%)
　以下に本発明を実施するための最適実施例を示す。本発明は実施例に限定されるものではなく、特許請求の範囲に基づいて定められ、かつ実施例に当業者に公知の事項を加えて変形できる。 The following is an optimum embodiment for carrying out the present invention. The present invention is not limited to the embodiments, but is defined based on the scope of claims and can be modified by adding matters known to those skilled in the art to the embodiments.
ブラシの構造
　図１は実施例の銅黒鉛質ブラシ２（以下、「ブラシ」）を示し、４は整流子などの摺動相手８との摺動面で、ブラシ２はリード線６を備え、図の矢印の向きに摺動面４へ向けて加圧されている。ブラシ２は単層でも２層あるいは３層でも良く、多層の場合、いずれかの層にホウ素化合物を所定量含んでいればよい。 Structure Figure 1 of the brush embodiment of the copper-graphite brush 2 (hereinafter, "brush") indicates, 4 in the sliding surface of the sliding partner 8 such as commutator, the brush 2 is provided with a lead wire 6, Pressure is applied toward the sliding surface 4 in the direction of the arrow in the figure. The brush 2 may be a single layer, two layers, or three layers. In the case of multiple layers, it is sufficient that a predetermined amount of a boron compound is contained in any layer.
ブラシの製造
　天然の鱗状黒鉛に対し、メタノールに溶解したフェノール樹脂を混合し、ミキサーで均一に混練し、乾燥機でメタノールを乾燥させた後、衝撃型粉砕器で粉砕し、80メッシュパスの篩（198μｍパスの篩）で篩い分けて、樹脂処理黒鉛粉体を得た。この樹脂処理黒鉛粉体部に、電解銅粉（平均粒径40μｍ）、ホウ酸（H3BO3）の粉末、及び二硫化モリブデンを加えて、Ｖ型混合機で混合し、配合粉を得た。H3BO3はH2B4O7などの他のホウ酸に変えて良く、またB2O3などのホウ素酸化物に変えても良く、ホウ素化合物は粉末として配合する。二硫化モリブデンは二硫化タングステン等の他の固体潤滑剤に変えても良く、これ以外の成分を含有させても良い。 Manufacture of brushes Phenol resin dissolved in methanol is mixed with natural scaly graphite, uniformly kneaded with a mixer, dried with a dryer, pulverized with an impact pulverizer, and sieved with an 80 mesh pass. Sieving with (198 μm pass sieve) to obtain resin-treated graphite powder. Electrolytic copper powder (average particle size 40 μm), boric acid (H 3 BO 3 ) powder, and molybdenum disulfide are added to the resin-treated graphite powder, and mixed with a V-type mixer to obtain a blended powder. It was. H 3 BO 3 may be changed to other boric acid such as H 2 B 4 O 7 or may be changed to boron oxide such as B 2 O 3. The boron compound is blended as a powder. Molybdenum disulfide may be replaced with other solid lubricants such as tungsten disulfide, and may contain other components.
　なお潤滑性の点から黒鉛含有量を35mass%以上とし、これに伴いCu含有量を64mass%以下とすることが好ましく、導電性の点からCu含有量を19mass%以上とし、これに伴い黒鉛含有量を80mass%以下とすることが好ましい。なおCuと黒鉛との比率を変えても、ブラシの曲げ強度と外観へのホウ素化合物含有量の影響は、表１に示す実施例及び比較例と同様であった。　 Note that the graphite content is 35 mass% or more from the viewpoint of lubricity, and accordingly, the Cu content is preferably 64 mass% or less, and the Cu content is 19 mass% or more from the viewpoint of conductivity, and accordingly the graphite content is included. The amount is preferably 80 mass% or less. In addition, even if it changed the ratio of Cu and graphite, the influence of the boron compound content on the bending strength and external appearance of a brush was the same as that of the Example and comparative example which are shown in Table 1. *
　配合粉をホッパから型内に投入し、リード線６の先端を埋め込むように、4×10８Pa（48×9800Ｎ／cm２）の圧力でモールド成形し、還元雰囲気の電気炉で700℃で焼結し、表１に示す組成のブラシを得た。なお焼成温度は600℃～1000℃が好ましい。 The compounded powder is put into the mold from the hopper and molded at a pressure of 4 × 10 8 Pa (48 × 9800 N / cm 2 ) so as to embed the tip of the lead wire 6, and at 700 ° C. in a reducing atmosphere electric furnace Sintering was performed to obtain a brush having the composition shown in Table 1. The firing temperature is preferably 600 ° C to 1000 ° C.
表１
　　　　　　　Cu　　黒鉛　　ホウ素　　 残部 
比較例１　　51.5　　46.2　　0 　 　　　2.3
　
実施例１　　51.3　　46.3　　0.1　　　　2.3
実施例２　　51.2　　46.2　　0.3　　　　2.3
実施例３　　51.2　　46.0　　0.5　　　　2.3
実施例４　　51.0　　45.9　　0.8　　　　2.3
実施例５　　50.9　　45.8　　1.0　　　　2.3
実施例６　　50.5　　45.2　　2.0　　　　2.3
　
比較例２　　49.8　　44.9　　3.0　　　　2.3
比較例３　　48.7　　44.0　　5.0　　　　2.3
比較例４　　47.6　　43.1　　7.0　　　　2.3
*　単位はmass%で、残部はフェノール樹脂由来の炭素が1.3mass%、
二硫化モリブデンが0.8mass%、灰分が0.2mass%．
　 Table 1
Cu Graphite Boron The balance
Comparative Example 1 51.5 46.2 0 2.3

Example 1 51.3 46.3 0.1 2.3
Example 2 51.2 46.2 0.3 2.3
Example 3 51.2 46.0 0.5 2.3
Example 4 51.0 45.9 0.8 2.3
Example 5 50.9 45.8 1.0 2.3
Example 6 50.5 45.2 2.0 2.3

Comparative Example 2 49.8 44.9 3.0 2.3
Comparative Example 3 48.7 44.0 5.0 2.3
Comparative Example 4 47.6 43.1 7.0 2.3
* The unit is mass%, the balance is 1.3mass% of phenol resin-derived carbon,
Molybdenum disulfide is 0.8 mass% and ash content is 0.2 mass%.
　図２は、実施例６でのブラシ切断面のEPMA（Electron Probe Micro Analysis）画像を示す。B元素の分布とO元素の分布はほぼ一致し、Cu元素の分布と一致しない。このことはホウ素は、ホウ素の酸化物もしくはホウ酸として、粒子状の形態で存在することを示している。またこのことは、ホウ酸（H3BO3）としてホウ素を配合したこととも対応する。 FIG. 2 shows an EPMA (Electron Probe Micro Analysis) image of the brush cut surface in Example 6. The distribution of B element and the distribution of O element are almost the same, but not the distribution of Cu element. This indicates that boron exists in the form of particles as boron oxide or boric acid. This also corresponds to the incorporation of boron as boric acid (H 3 BO 3 ).
　図３は実施例４のブラシ表面を、図４は比較例２のブラシ表面を、図５は比較例４のブラシ表面を示す写真である。写真のブラシは、前記実施例に記載の製造方法で作成したテスト片であり、寸法は20mm×10mm×5mmとなっている。B2O3換算でのホウ素含有量が0.1～2mass%の実施例ではブラシ表面は平滑でそのまま使用できるが、ホウ素含有量が3～7mass%の比較例では、ブラシ表面にホウ酸に由来すると考えられる塊が表れ、表面に凹凸が生じている。そしてこの塊はブラシの使用中に脱落しやすいため、ホウ素含有量が3mass%以上の比較例は実用的ではない。 3 is a photograph showing the brush surface of Example 4, FIG. 4 is a photograph showing the brush surface of Comparative Example 2, and FIG. 5 is a photograph showing the brush surface of Comparative Example 4. The brush in the photograph is a test piece prepared by the manufacturing method described in the above example, and the dimensions are 20 mm × 10 mm × 5 mm. In Examples where the boron content in terms of B 2 O 3 is 0.1 to 2 mass%, the brush surface is smooth and can be used as it is. However, in the comparative example where the boron content is 3 to 7 mass%, Possible lumps appear and the surface is uneven. And since this lump is easy to fall off during use of a brush, the comparative example whose boron content is 3 mass% or more is not practical.
　実施例でも比較例でも、ブラシの抵抗率等は実用上問題がない範囲であった。焼成後のブラシの曲げ強度と、200℃で100時間エージング後及び200℃で400時間エージング後の曲げ強度を測定した。なお曲げ強度は3点曲げ強度である。曲げ強度とブラシの外観の評価結果を表２に示す。　 In both the examples and the comparative examples, the brush resistivity and the like were in a range where there was no practical problem. The bending strength of the brush after firing and the bending strength after aging at 200 ° C. for 100 hours and after aging at 200 ° C. for 400 hours were measured. The bending strength is a three-point bending strength. Table 2 shows the evaluation results of the bending strength and the appearance of the brush. *
表２
　　　　　　　　　　　　　　　曲げ強度（MPa）　　　　　　　　　外観
　　　　　ホウ素含有量　焼成後　100時間後　400時間後　 経時変化　　　
比較例１　　0　　　　　 15.3　　　24.1　　　22.4　　　　7.1　　　○
　
実施例１　　0.1mass%　　24.0　　　25.5　　　25.2　　　　1.2　　　○
実施例２　　0.3mass%　　24.0　　　25.4　　　25.3　　　　1.3　　　○
実施例３　　0.5mass%　　26.7　　　27.8　　　27.9　　　　1.2　　　○
実施例４　　0.8mss%　　 28.5　　　30.2　　　29.5　　　　1.0　　　○
実施例５　　1.0mass%　　27.5　　　26.3　　　28.6　　　　1.1　　　○
実施例６　　2.0mass%　　27.1　　　29.5　　　29.0　　　　1.9　　　○
　
比較例２　　3.0mass%　　28.5　　　30.9　　　30.9　　　　2.4　　　△
比較例３　　5.0mass%　　25.8　　　29.3　　　24.3　　　－1.5　　　×
比較例４　　7.0mass%　　29.1　　　28.6　　　22.2　　　－6.9　　　×
＊　曲げ強度はJIS Z 2248 「金属材料曲げ試験方法」に準拠して測定．
＊　100時間後は200℃で100時間後の曲げ強度を、400時間後は200℃で400時間後の曲げ強度を示す．
＊　強度はMPa単位、経時変化は200℃400時間のエージングによる曲げ強度の変化．
＊　外観は、ブラシ表面が平滑でそのまま使用できるものを○、
　　　　　　表面に塊があるが、切削すれば使用できるものを△、
　　　　　　表面に塊が多数あり、使用できないものを×とした.
  Table 2
Bending strength (MPa) Appearance
Boron content 100 hours after firing 400 hours later Change with time
Comparative Example 1 0 15.3 24.1 22.4 7.1 ○

Example 1 0.1 mass% 24.0 25.5 25.2 1.2 ○
Example 2 0.3 mass% 24.0 25.4 25.3 1.3 ○
Example 3 0.5 mass% 26.7 27.8 27.9 1.2 ○
Example 4 0.8 mss% 28.5 30.2 29.5 1.0 ○
Example 5 1.0 mass% 27.5 26.3 28.6 1.1 ○
Example 6 2.0 mass% 27.1 29.5 29.0 1.9

Comparative Example 2 3.0 mass% 28.5 30.9 30.9 2.4
Comparative Example 3 5.0 mass% 25.8 29.3 24.3 -1.5 ×
Comparative Example 4 7.0 mass% 29.1 28.6 22.2 -6.9 ×
* Bending strength was measured according to JIS Z 2248 “Metal material bending test method”.
* The bending strength after 100 hours at 200 ° C after 100 hours, and the bending strength after 400 hours at 200 ° C after 400 hours.
* Strength is in units of MPa, change with time is change in bending strength due to aging at 200 ° C for 400 hours.
* Appearance is that the brush surface is smooth and can be used as is.
There are lumps on the surface.
There were many lumps on the surface, and those that could not be used were marked as x.
　表２から、以下のことが分かった。B2O3換算でホウ素化合物濃度が0.1mass%未満では、ブラシの曲げ強度が不足する。0.1mass%以上0.5mass%未満では、曲げ強度は向上するもののやや低い。0.5mass%以上1.0mass%以下では、曲げ強度は高く、高温での曲げ強度の経時変化も小さい。1.0mass%超2.0mass%以下では、曲げ強度は高いものの、高温での曲げ強度の経時変化がやや大きくなる。2.0mass%超では、外観不良のため使用不可で、かつ経時試験中に割れが発生することがあった。これらのことから、ホウ素化合物の含有量は0.1mass%以上2.0mass%以下とし、好ましくは0.1mass%以上1.0mass%以下、最も好ましくは0.5mass%以上1.0mass%以下とする。 Table 2 shows the following. When the boron compound concentration in terms of B 2 O 3 is less than 0.1 mass%, the bending strength of the brush is insufficient. If it is 0.1 mass% or more and less than 0.5 mass%, the bending strength is improved but slightly low. In the range of 0.5 mass% to 1.0 mass%, the bending strength is high, and the change with time in bending strength at high temperatures is small. If it is more than 1.0 mass% and not more than 2.0 mass%, the bending strength is high, but the change with time in the bending strength at a high temperature becomes slightly large. If it exceeds 2.0 mass%, it cannot be used due to poor appearance, and cracking may occur during the time-lapse test. For these reasons, the boron compound content is 0.1 mass% or more and 2.0 mass% or less, preferably 0.1 mass% or more and 1.0 mass% or less, and most preferably 0.5 mass% or more and 1.0 mass% or less.
　前記のように、本発明のDCモータ用の銅黒鉛ブラシは曲げ強度が高く、且つ高温下での経時変化が小さいため、特性を長時間維持することができる。このため、特に自動車のモータ、オールタネータ等のように、高温下で長期間使用される摺動部材に好適に用いることができる。 As described above, the copper graphite brush for a DC motor according to the present invention has high bending strength and small change with time at high temperature, so that the characteristics can be maintained for a long time. For this reason, it can be suitably used for sliding members that are used for a long period of time at high temperatures, such as automobile motors, alternators and the like.
２　銅黒鉛質ブラシ　　４　摺動面　　６　リード線　　８　摺動相手 2 Copper graphite brush 4 Sliding surface 6 Lead wire 8 Sliding partner

Claims (6)

  1. 　銅と黒鉛とを含有する銅黒鉛質ブラシにおいて、
    　B2O3換算で0.1mass%以上2.0mass%以下のホウ素化合物を、ホウ素酸化物あるいはホウ酸として含有することを特徴とする、銅黒鉛質ブラシ。     In a copper-graphite brush containing copper and graphite,
    A copper graphite brush characterized by containing a boron compound of 0.1 mass% or more and 2.0 mass% or less in terms of B 2 O 3 as boron oxide or boric acid.
  2. 　黒鉛を35mass%以上80mass%以下含有することを特徴とする、請求項１の銅黒鉛質ブラシ。 The copper-graphite brush according to claim 1, characterized by containing 35 mass% or more and 80 mass% or less of graphite.
  3. 　銅として電解銅粉を含有することを特徴とする、請求項１または２の銅黒鉛質ブラシ。 The copper graphite brush according to claim 1 or 2, characterized by containing electrolytic copper powder as copper.
  4. 　B2O3換算で0.1mass%以上1.0mass%以下のホウ素化合物を含有することを特徴とする、請求項１～３のいずれかの銅黒鉛質ブラシ。　　 The copper-graphite brush according to any one of claims 1 to 3, comprising a boron compound in an amount of 0.1 mass% to 1.0 mass% in terms of B 2 O 3 .
  5. 　ホウ素化合物を粒子状の形態で含有することを特徴とする、請求項１～４のいずれかの銅黒鉛質ブラシ。　　 The copper-graphite brush according to any one of claims 1 to 4, comprising a boron compound in a particulate form. *
  6. 　銅と黒鉛とホウ素化合物が各々粒子状の形態で存在することを特徴とする、請求項５の銅黒鉛質ブラシ。 The copper-graphite brush according to claim 5, wherein copper, graphite, and a boron compound each exist in a particulate form.
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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002080922A (en) * 2000-09-07 2002-03-22 Mitsubishi Materials Corp ARMATEUR-BRUSHING MATERIAL MADE OF Cu-GRAPHITE BASED SINTERED MATERIAL HAVING EXCELLENT WEAR RESISTANCE
JP2006187190A (en) * 2004-11-30 2006-07-13 Denso Corp Brush, commutator and commutation mechanism
JP2011212691A (en) * 2010-03-31 2011-10-27 Jfe Steel Corp Flux-cored welding wire for small diameter multi-electrode submerged arc welding
WO2016010104A1 (en) * 2014-07-17 2016-01-21 トライス株式会社 Laminate carbon brush for fuel pump motor

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101379680B (en) * 2006-02-24 2010-12-22 爱信精机株式会社 Method for manufacturing metal-graphite brush material for motor
CN101656385B (en) * 2009-10-20 2011-01-05 丽水市长新电器制造有限公司 Ultra-abrasion resistant multifunctional nano carbon brush and preparation method thereof
CN102142650B (en) * 2010-11-30 2013-11-20 施丽萍 Nano rare earth compound high-wear-resisting additive for electric brushes and preparation method thereof
CN102130407B (en) * 2010-12-24 2012-08-22 苏州东南碳制品有限公司 Carbon brush for truck starting motor as well as manufacture method and application thereof
KR20150018799A (en) * 2012-06-18 2015-02-24 도요탄소 가부시키가이샤 Metal-carbonaceous brush and method for producing same
CN103972758A (en) * 2014-03-05 2014-08-06 台州昊泽碳制品有限公司 Low-noise motor and electric brush combination
CN105098561B (en) * 2014-05-04 2018-12-18 苏州东南碳制品有限公司 A kind of preparation method and applications of hybrid electric vehicle starting motor carbon brush
CN106159623B (en) * 2014-12-31 2018-10-09 上海摩腾碳制品有限公司 A kind of wind-driven generator Special carbon brush and preparation method thereof
CN104804371A (en) * 2015-04-14 2015-07-29 芜湖中源赛特管业有限公司 Graphite brush and preparation method thereof
CN104901120A (en) * 2015-04-14 2015-09-09 芜湖中源赛特管业有限公司 Graphite brush and preparation method thereof

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002080922A (en) * 2000-09-07 2002-03-22 Mitsubishi Materials Corp ARMATEUR-BRUSHING MATERIAL MADE OF Cu-GRAPHITE BASED SINTERED MATERIAL HAVING EXCELLENT WEAR RESISTANCE
JP2006187190A (en) * 2004-11-30 2006-07-13 Denso Corp Brush, commutator and commutation mechanism
JP2011212691A (en) * 2010-03-31 2011-10-27 Jfe Steel Corp Flux-cored welding wire for small diameter multi-electrode submerged arc welding
WO2016010104A1 (en) * 2014-07-17 2016-01-21 トライス株式会社 Laminate carbon brush for fuel pump motor

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