JP2000100602A - Power resistor body, manufacture thereof and power circuit breaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a sintered body superior in uniformity and a reproducibility by comprising a step of mixing, forming and sintering a first and second granulated powders to manufacture a sintered body composed of a first and second regions, and a step of forming a pair of electrodes on opposite faces of the sintered body. SOLUTION: The resistor body 1 is composed of a discoidal sintered body 2, a pair of electrodes 3 formed on both circular faces of the sintered body 2, and an insulation layer 4 laid on the periphery of the sintered body 2. The sintered body 2 has a composition containing Al oxide and C, and is composed of a first region containing C a little or no C and a second region having a more C content than that of the first region. The water contents of a first and second granulated powders are pref. 7 to 15 wt.%. At the junction between the first and second regions the mutually contacted length pref. does not exceed 50% of the second region's circumference length in section.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【０００１】[0001]

【発明の属する技術分野】本発明は、電力用抵抗体、そ
の製造方法及び電力用遮断器に関し、具体的には、例え
ば高電圧装置、大容量コンデンサーの充放電装置、電力
用遮断器などに用いられて中性点接地抵抗器、固定抵抗
器、可変抵抗器、巻線抵抗器、抵抗器アレーとして好適
な電力用抵抗体、その製造方法及びその電力用抵抗体を
投入抵抗体として備えた電力用遮断器に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power resistor, a method of manufacturing the same, and a power circuit breaker. Used as a neutral point grounding resistor, a fixed resistor, a variable resistor, a wire wound resistor, a power resistor suitable as a resistor array, a manufacturing method thereof, and the power resistor provided as a closing resistor. The present invention relates to a power circuit breaker.

【０００２】[0002]

【従来の技術】一般に、電力用抵抗器の材料は、金属系
抵抗材料、金属酸化物系抵抗材料および非金属系抵抗材
料に大別される。これらのうち、金属酸化物系抵抗材料
は、他の材料に比べて耐熱性、耐電圧電流性および高電
気エネルギーを吸収する耐エネルギー量が高いという特
徴を有する。代表的な金属酸化物系抵抗体としては、絶
縁性の酸化アルミニウム結晶中に導電性のカーボン粉末
を分散させ、粘土で焼き固めたカーボン粒子分散型セラ
ミック抵抗体が記載されている。かかる抗体中として
は、カーボン含有量が１．５〜２．０重量％であること
が記載されている。2. Description of the Related Art In general, the materials of power resistors are roughly classified into metal-based resistance materials, metal-oxide-based resistance materials, and non-metal-based resistance materials. Among these, the metal oxide-based resistance material is characterized by high heat resistance, high withstand voltage and current, and high withstand energy for absorbing high electric energy as compared with other materials. As a typical metal oxide-based resistor, there is described a carbon particle-dispersed ceramic resistor in which conductive carbon powder is dispersed in insulating aluminum oxide crystals and baked with clay. It is described that such an antibody has a carbon content of 1.5 to 2.0% by weight.

【０００３】ところで、一般に酸化アルミニウム粉末に
カーボン粉末を添加し焼結体を製造しようとすると、前
記酸化アルミニウムの焼結性が阻害される。このため、
前述したカーボン粒子分散型セラミック抵抗体は、酸化
アルミニウム粉末にカーボン粉末を添加しているため、
前記酸化アルミニウムの焼結性が阻害される。このた
め、前述したカーボン粒子分散型セラミック抵抗体は、
酸化アルミニウム粉末にカーボン粉末を添加し、さらに
前記酸化アルミニウム粉末の焼結性を補う目的で粘土を
加えて焼結している。しかしながら、前記粘土の添加は
単に前記酸化アルミニウムとカーボン粉末を結合させる
が、焼結性を向上させないため、得られた抵抗体の気孔
率は１０〜３０％と高く緻密性が低下しているため、次
のような問題を招く。In general, when a carbon powder is added to aluminum oxide powder to produce a sintered body, the sinterability of the aluminum oxide is hindered. For this reason,
Since the carbon particle-dispersed ceramic resistor described above adds carbon powder to aluminum oxide powder,
The sinterability of the aluminum oxide is hindered. For this reason, the carbon particle dispersed ceramic resistor described above
Carbon powder is added to the aluminum oxide powder, and clay is added and sintered for the purpose of supplementing the sinterability of the aluminum oxide powder. However, the addition of the clay merely binds the aluminum oxide and the carbon powder, but does not improve the sinterability. Therefore, the porosity of the obtained resistor is as high as 10 to 30% and the denseness is reduced. This leads to the following problems.

【０００４】すなわち、前記抵抗体を開閉時に発生する
サージを吸収したり、遮断容量を増加させるために遮断
接点と並列に接続される遮断器の投入抵抗体として用い
た場合、抵抗体の緻密性の低下に起因して体積当りの熱
容量が２Ｊ／ｃｍ³ ・Ｋ程度と小さくなるために、サー
ジ等のエネルギーの吸収に伴って抵抗体の温度上昇が著
しくなる。また通電時にカーボン粉末が気孔内で放電を
起こして、貫通放電が発生する。したがって、前述した
カーボン粒子分散型セラミック抵抗体を用いた遮断器
は、抵抗体の格納スペースが大きくなるとともに信頼性
を確保するためには遮断容量を低く抑える必要があっ
た。That is, when the resistor is used as a closing resistor of a circuit breaker connected in parallel with a breaking contact in order to absorb a surge generated at the time of opening and closing and to increase a breaking capacity, the resistance of the resistor is increased. Since the heat capacity per volume becomes as small as about 2 J / cm ³ · K due to the decrease of the temperature, the temperature rise of the resistor becomes remarkable with the absorption of energy such as surge. Further, at the time of energization, the carbon powder causes a discharge in the pores to generate a through discharge. Therefore, in the circuit breaker using the carbon particle-dispersed ceramic resistor described above, the storage space for the resistor has to be large, and the breaking capacity has to be kept low to ensure reliability.

【０００５】さらに、このような抵抗体において、１０
³ Ω・ｃｍを超える高い抵抗率を有する焼結体を得たい
場合に、導電性をもたらすカーボン粒子がわずかな数で
接続されることから、製造条件の変動が敏感に反映され
るため、優れた均一性をもつ焼結体を歩留まり良く製造
することが困難であった。また、このような抵抗体を製
造するにあたっては、一般に、主原料のアルミナ粉末と
導電性をもたらすカーボン粉末との混合において、これ
ら原料粉末をボールなどの粉砕媒体と溶液を用いていわ
ゆる湿式混合しスラリー状態にした後、混合物を熱風中
に噴霧させて造粒する、いわゆる、スプレードライ法に
より造粒が行われる。このような方法で得られる造粒粉
は、粒子径が比較的よく揃った球状粒子が得られるもの
の、原料粒子の緻密な充填性に欠けるとともに、球状粒
子の中心部に穴が存在する場合が多い。このような造粒
粉を用いて成形した場合には、造粒粒子同士の接続部に
おいてその接続面が複雑な形状をなす場合が有り、特に
カーボンを含んだ粒子同士の接続において期待される導
電的接続が得られない部分が発生し、電気的に均一性を
持った焼結体の実現が難しい面があった。Further, in such a resistor, 10
^When it is desired to obtain a sintered body having a high resistivity exceeding ³ Ω · cm, since a small number of carbon particles that provide conductivity are connected, fluctuations in manufacturing conditions are sensitively reflected. It is difficult to produce a sintered body having uniformity with good yield. In producing such a resistor, generally, in the mixing of alumina powder as a main raw material and carbon powder that provides conductivity, these raw material powders are so-called wet-mixed with a grinding medium such as a ball using a solution. After the slurry is formed, the mixture is sprayed in hot air and granulated, that is, granulation is performed by a so-called spray dry method. Granulated powder obtained by such a method can obtain spherical particles having a relatively uniform particle diameter, but lacks dense packing of raw material particles, and may have a hole in the center of the spherical particles. Many. In the case of molding using such granulated powder, there is a case where the connecting surface of the connecting portion of the granulated particles has a complicated shape, and especially the conductive property expected in the connection of the particles containing carbon. There was a portion where electrical connection could not be obtained, and it was difficult to realize a sintered body having electrical uniformity.

【０００６】[0006]

【発明が解決しようとする課題】以上のように電力用抵
抗体には、十分緻密でかつ高均一性を有する焼結体を歩
留まりよく製造することが困難であるという問題があ
る。本発明は上記実状を考慮してなされたもので、単位
体積あたりの熱容量が大きく、適切かつ安定した電気抵
抗値を有し、サージ吸収による抵抗値の経時変化が小さ
く、焼結体の均一性に優れ、再現性良く製造可能な電力
用抵抗体及びその製造方法を提供することを目的とす
る。本発明の第２の目的は、遮断容量が大きく、遮断性
能の安定した投入抵抗ユニットを備え、小型、高性能化
を達成した電力用遮断器を提供することにある。As described above, the power resistor has a problem that it is difficult to manufacture a sintered body having sufficiently high density and high uniformity with a high yield. The present invention has been made in consideration of the above-mentioned situation, has a large heat capacity per unit volume, has an appropriate and stable electric resistance, has a small change with time in resistance due to surge absorption, and has a uniform sintered body. It is an object of the present invention to provide a power resistor which is excellent in reproducibility and can be manufactured with good reproducibility, and a manufacturing method thereof. A second object of the present invention is to provide a power circuit breaker having a large breaking capacity, a closing resistance unit having a stable breaking performance, a small size and high performance.

【０００７】[0007]

【課題を解決するための手段】本願第１の発明は、酸化
アルミニウムを主体とする第１の粉末を、乾燥状態で分
散・混合する分散工程と、分散・混合中の第１の粉末に
溶液状のペーストを加え、第１の粉末を凝集させる凝集
工程と、凝集された第１の粉末を乾燥させる工程と、乾
燥された第１の粉末を分級し、第１の造粒粉を得る工程
と、第１の粉末よりカーボンを多量に含有する、酸化ア
ルミニウムおよびカーボンを含有する第２の粉末を、乾
燥状態で分散・混合する工程と、分散・混合中の第２の
粉末に溶液状のペーストを加え、第２の粉末を凝集させ
る工程と、凝集された第２の粉末を乾燥させる工程と、
乾燥された第２の粉末を分級し、第２の造粒粉を得る工
程と、前記第１および第２の造粒粉を混合、成形、焼結
し、酸化アルミニウムを主体とする第１の領域と、第１
の領域よりカーボン含有量の多い第２の領域とからなる
焼結体を製造する工程と、前記焼結体の対向する面に一
対の電極を形成する工程とを有する電力用抵抗体の製造
方法である。Means for Solving the Problems A first invention of the present application is a dispersion step of dispersing and mixing a first powder mainly composed of aluminum oxide in a dry state, and a step of dispersing the first powder during dispersion and mixing into a solution. Agglomerating step of adding a paste in a shape and aggregating a first powder, a step of drying the agglomerated first powder, and a step of classifying the dried first powder to obtain a first granulated powder Dispersing and mixing, in a dry state, a second powder containing aluminum oxide and carbon, which contains a larger amount of carbon than the first powder; Adding a paste and aggregating the second powder; drying the agglomerated second powder;
Classifying the dried second powder to obtain a second granulated powder, and mixing, molding and sintering the first and second granulated powder to form a first granulated powder mainly composed of aluminum oxide. Area and the first
A method for manufacturing a power resistor, comprising: a step of manufacturing a sintered body including a second region having a higher carbon content than the region; and a step of forming a pair of electrodes on opposing surfaces of the sintered body. It is.

【０００８】本願第２の発明は、前記第１あるいは第２
の粉末を凝集させる工程は、凝集された前記第１あるい
は第２の粉末中の水分含有量を７〜１５重量％の範囲に
することを特徴とする前記第１の発明に記載の電力用抵
抗体の製造方法である。The second invention of the present application is the first or second invention.
The step of aggregating the powder according to the first aspect, wherein the water content in the agglomerated first or second powder is set in a range of 7 to 15% by weight. It is a method of manufacturing the body.

【０００９】本願第３の発明は、酸化アルミニウム及び
カーボンを含む焼結体と、この焼結体の対向する面に形
成された一対の電極とを具備し、前記焼結体はカーボン
含有量が少ないかもしくはカーボンを含まない第１領域
と、この第１領域よりもカーボン含有量が多く、かつ前
記電極に電気的に接続される第２の領域とを有する電力
用抵抗体において、前記第１の領域と第２の領域の接合
部が、相互に接する長さが断面上で領域周囲長の５０％
未満である電力用抵抗体である。The third invention of the present application comprises a sintered body containing aluminum oxide and carbon, and a pair of electrodes formed on opposing surfaces of the sintered body, wherein the sintered body has a carbon content of In a power resistor having a first region that is small or does not contain carbon, and a second region that has a higher carbon content than the first region and is electrically connected to the electrode, In the cross section, the length of the junction between the region and the second region is 50% of the region peripheral length on the cross section.
Less than the power resistor.

【００１０】本願第４の発明は、電流経路に配置される
主開閉手段と、前記電流経路に前記主開閉手段に対して
電気的に並列に接続され、前記主開閉手段の閉状態への
切り替えよりも先行して閉状態に切替えられる補助開閉
手段と、前記補助開閉手段に電気的に直列に接続された
前記第３の発明に記載の電力用抵抗体とを有する電力用
遮断器である。According to a fourth aspect of the present invention, there is provided a main switching means disposed in a current path, and electrically connected to the current path in parallel with the main switching means, for switching the main switching means to a closed state. A power circuit breaker comprising: an auxiliary switching device that is switched to a closed state earlier than before; and a power resistor according to the third aspect of the present invention electrically connected to the auxiliary switching device in series.

【００１１】本願第１の発明においては、焼結体として
は、カーボン含有量が少ないかもしくはカーボンを含ま
ない第１領域と、この第１領域よりカーボン含有量が多
く、かつ前記一対の電極に繋がるように配置された第２
領域とを有する電力用抵抗体の製造において、第１領域
と第２領域を形成する粉末をそれぞれ、乾燥状態で分散
・混合する分散工程と、分散・混合中の粉末に溶液状の
バインダを加えることにより凝集させる凝集工程と、水
分を減少させる乾燥工程と、粒子径を整え、第１及び第
２造粒粉末を調製するための分級工程と、前記第１の造
粒粉末と前記第２の造粒粉末とを混合した後、成型、焼
結することにより焼結体を作製する工程と、前記焼結体
の対抗する主面に一対の電極を形成する工程とを含んで
いるので、焼結体の緻密性及び均一性を向上できること
により、単位体積あたりの熱容量が大きく、適切かつ安
定した電気抵抗値を有し、サージ吸収による抵抗値の経
時変化が小さく、焼結体の均一性に優れ、再現性良く製
造することができる。In the first invention of the present application, the sintered body includes a first region having a low carbon content or containing no carbon and a first region having a higher carbon content than the first region, and The second arranged to connect
In the production of a power resistor having a region, a dispersion step of dispersing and mixing the powder forming the first region and the second region in a dry state, respectively, and adding a solution binder to the powder being dispersed and mixed An aggregating step for agglomerating thereby, a drying step for reducing water, a classifying step for adjusting the particle diameter and preparing first and second granulated powders, and a step for preparing the first granulated powder and the second granulated powder. Since it includes a step of producing a sintered body by mixing and granulating and then forming and sintering the granulated powder, and a step of forming a pair of electrodes on a main surface of the sintered body opposed to the sintered body, By improving the compactness and uniformity of the consolidated body, the heat capacity per unit volume is large, it has an appropriate and stable electric resistance value, the resistance change over time due to surge absorption is small, and the uniformity of the sintered body is improved. Excellent and can be manufactured with good reproducibility .

【００１２】また、本願第２の発明においては、凝集工
程後の粉末の水分含有量が７〜１５重量％の範囲にある
ので、電力用抵抗体として好適な抵抗率と十分な緻密性
とを確保することができる。In the second aspect of the present invention, since the water content of the powder after the agglomeration step is in the range of 7 to 15% by weight, the resistivity suitable for the power resistor and the sufficient compactness are obtained. Can be secured.

【００１３】さらに、本願第３の発明においては、焼結
体において、第１の領域と第２の領域の接合部におい
て、相互に接する長さが断面上で領域周囲長の５０％未
満であるので、第２の領域どうしの電気的接続を均一に
実現することができる。Further, in the third invention of the present application, in the sintered body, the length of the joint between the first region and the second region is less than 50% of the peripheral length of the region on the cross section. Therefore, electrical connection between the second regions can be realized uniformly.

【００１４】また、本願第４の発明においては、本願第
３の発明に記載の抵抗体を有しているので、遮断容量が
大きく、遮断性能の安定した投入抵抗体ユニットを備
え、小型、高性能化を達成することができる。In the fourth aspect of the present invention, since the resistor according to the third aspect of the present invention is provided, a closing resistor unit having a large breaking capacity and a stable breaking performance is provided. Performance can be achieved.

【００１５】[0015]

【発明の実施の形態】以下、本発明の実施の形態を図面
を参照しながら説明する。図１は本発明の実施の形態に
係る電力用抵抗体の構成を示す断面図、図２は図１の焼
結体の微構造を模式的に示す図、図３は図２の第２領域
を拡大して模式的に示す図である。抵抗体１は円板状の
焼結体２と、焼結体２の円形両面に形成された一対の電
極３と、焼結体２の外周面に被覆された絶縁層４とから
構成されている。Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing a configuration of a power resistor according to an embodiment of the present invention, FIG. 2 is a diagram schematically showing a microstructure of the sintered body of FIG. 1, and FIG. 3 is a second region of FIG. It is a figure which expands and shows typically. The resistor 1 includes a disc-shaped sintered body 2, a pair of electrodes 3 formed on both circular surfaces of the sintered body 2, and an insulating layer 4 covering the outer peripheral surface of the sintered body 2. I have.

【００１６】焼結体２は、酸化アルミニウム及び、カー
ボンを含む組成を有する。焼結体２は、図２に示すよう
に、カーボン量が少ないかもしくはカーボンを含まない
第１領域５とこの第１領域５よりカーボン量の多い第２
領域６とからなり、第１領域５は実質的に絶縁性を示
し、第２領域６は導電性を示す。焼結体２において、第
２領域６は３次元的なネットワーク構造で互いに接続さ
れるとともに、一対の電極３に繋がるように配置され
る。第２領域６の接続状態及び抵抗率により、焼結体２
の抵抗値が制御される。The sintered body 2 has a composition containing aluminum oxide and carbon. As shown in FIG. 2, the sintered body 2 has a first region 5 containing a small amount of carbon or containing no carbon and a second region 5 containing a larger amount of carbon than the first region 5.
The first region 5 is substantially insulative, and the second region 6 is conductive. In the sintered body 2, the second regions 6 are connected to each other in a three-dimensional network structure, and are arranged so as to be connected to the pair of electrodes 3. The sintered body 2 depends on the connection state and the resistivity of the second region 6.
Is controlled.

【００１７】第２領域６は、図３に示すように、絶縁性
の酸化アルミニウム粒子８の粒界に導電性のカーボン９
が存在する形態を有し、カーボン８により複数の第２領
域６を相互に電気的に接続している。As shown in FIG. 3, the second region 6 has conductive carbon 9 at the grain boundaries of the insulating aluminum oxide particles 8.
Exist, and the plurality of second regions 6 are electrically connected to each other by the carbon 8.

【００１８】第２領域６では、該領域のカーボン含有量
により、該領域の抵抗率が制御可能となっている。従来
の湿式混合、スプレードライ造粒法による場合、局所的
に図４のような構造を有し、第２の領域間の電気的な接
続が不均一となり、エネルギー吸収耐量の低下をきたす
ことがある。一方、第１領域と第２領域を形成する粉末
をそれぞれ、乾燥状態で分散・混合する分散工程と、分
散・混合中の粉末に溶液状のバインダを加えることによ
り凝集させる凝集工程と、水分を減少させる乾燥工程
と、粒子径を整え、第１及び第２造粒粉末を調製するた
めの分級工程を用いて得られることにより、第１領域の
造粒粉末と第２領域の造粒粉末が適切に緻密化されるた
め、焼結体における第２領域間が相互に安定な接続が得
られる。In the second region 6, the resistivity of the region can be controlled by the carbon content of the region. In the case of the conventional wet mixing and spray dry granulation methods, the structure locally has a structure as shown in FIG. 4, the electrical connection between the second regions becomes uneven, and the energy absorption resistance may be reduced. is there. On the other hand, a dispersion step of dispersing and mixing the powder forming the first region and the second region in a dry state, an aggregation step of adding a solution binder to the powder being dispersed and mixed, and By being obtained using a drying step to reduce the particle size and a classifying step to prepare the first and second granulated powders, the granulated powder in the first region and the granulated powder in the second region are obtained. Since it is appropriately densified, a stable connection between the second regions in the sintered body is obtained.

【００１９】比較的高抵抗率をもつ焼結体を得る場合、
第２領域６の抵抗率を適度に大きくして第２の領域６間
の接続数を十分大きくとることが可能となる。これによ
り、製造時の焼結雰囲気、温度分布等による焼結体内部
の均一性への悪影響を相対的に小さくでき、製造歩留り
を向上できる。When obtaining a sintered body having a relatively high resistivity,
By appropriately increasing the resistivity of the second region 6, the number of connections between the second regions 6 can be made sufficiently large. As a result, adverse effects on the uniformity inside the sintered body due to the sintering atmosphere, temperature distribution, and the like during the manufacturing can be relatively reduced, and the manufacturing yield can be improved.

【００２０】本発明の電力用抵抗体は、例えば以下のよ
うにして作製することができる。酸化アルミニウムは平
均粒子径が１μｍ以下であり、焼結性を良くするために
好ましくは０．５μｍ以下のものが原料粉末とされるカ
ーボン粉末は０．１μｍ以下の粒子径が焼結性の確保の
ために好ましく、微粉になる程好ましい。このような酸
化アルミニウム原料粉末と平均粒子径が０．１μｍ以下
のカーボン粉末、および必要に応じて添加材粉末を高速
で回転する攪拌ピンを備えた混合容器中で、乾燥状態で
混合し、第１及び第２の混合粉末をそれぞれ得る。The power resistor of the present invention can be manufactured, for example, as follows. Aluminum oxide has an average particle diameter of 1 μm or less, and preferably 0.5 μm or less is used as a raw material powder to improve sinterability. Carbon powder having a particle diameter of 0.1 μm or less ensures sinterability. And finer powder is more preferable. Such an aluminum oxide raw material powder and a carbon powder having an average particle diameter of 0.1 μm or less, and an additive powder as needed, are mixed in a dry state in a mixing vessel equipped with a stirring pin that rotates at a high speed. First and second mixed powders are obtained respectively.

【００２１】焼結体中のカーボン含有量の異なる第１又
は第２領域を形成する際に該領域のカーボン含有量は電
気的性質に合わせて制御可能である。すなわち、実質的
に絶縁性の第１の領域を形成するためのカーボン含有量
が少ない第１の混合粉末と、導電性の第２の領域を形成
するためのカーボン含有量が多い第２の混合粉末とは、
それぞれの電気的性質を表す範囲でカーボン含有量を制
御可能である。これらのカーボン含有量の異なるそれぞ
れの混合粉末に、成形体を作成するときのために所望に
より適宜パラフィン、ポリビニルアルコール等の成形用
バインダーが添加可能であるが、この場合、これら成形
用バインダーも焼結体中のカーボン源になるため、それ
を考慮し、予めカーボン粉末量の調整の必要がある。When forming the first or second region having a different carbon content in the sintered body, the carbon content of the region can be controlled in accordance with the electrical properties. That is, a first mixed powder having a low carbon content for forming a substantially insulating first region and a second mixed powder having a large carbon content for forming a conductive second region. What is powder?
It is possible to control the carbon content within a range representing each electrical property. To each of the mixed powders having different carbon contents, a molding binder such as paraffin or polyvinyl alcohol can be appropriately added as required for forming a molded body. In this case, these molding binders are also sintered. Since it becomes a carbon source in the aggregate, it is necessary to adjust the amount of carbon powder in advance in consideration of the carbon source.

【００２２】混合粉末は混合工程と同様、高速で回転す
る攪拌ピンを備えた混合容器中で攪拌中の粉末に、水又
は有機溶媒にバインダー成分を分散した溶液をスプレー
状に所定量添加し、攪拌を維持することでバインダを添
加された混合粉末を適度に凝集させる。凝集粉末はバイ
ンダ溶液を含むため、湿った状態であり、乾燥後メッシ
ュを通過する等により整粒し、第１及び第２の造粒粉末
が調整される。ここに、造粒粉は乾燥前の凝集粉末をメ
ッシュに通過させた後、乾燥しても良い。また、混合と
バインダー溶液添加による凝集は連続して行うことが出
来る。As in the mixing step, a predetermined amount of a solution obtained by dispersing a binder component in water or an organic solvent is added to the powder being stirred in a mixing vessel equipped with a stirring pin rotating at a high speed in the same manner as in the mixing step. By maintaining the stirring, the mixed powder to which the binder has been added is appropriately aggregated. Since the agglomerated powder contains a binder solution, the agglomerated powder is in a wet state, and after drying, is sized by passing through a mesh or the like, so that the first and second granulated powders are adjusted. Here, the granulated powder may be dried after passing the aggregated powder before drying through a mesh. The mixing and the aggregation by adding the binder solution can be performed continuously.

【００２３】各造粒粉末は、所定の比率により、例えば
Ｖ型ミキサーにより混合され、混合造粒粉末となる。混
合造粒粉末を成形し、焼結し、焼結体とする。成形は金
型プレス、押し出しおよび射出成形などが適用可能であ
る。金型成形を用いる場合、焼結体の密度を高めるため
に２００ｋｇ／ｃｍ² 以上の成形圧力が望ましい。な
お、これ以下の成形圧力であると焼結体の相対密度が低
く、単位体積当たりの熱容量が低下する。Each granulated powder is mixed at a predetermined ratio, for example, by a V-type mixer to form a mixed granulated powder. The mixed granulated powder is molded and sintered to obtain a sintered body. Mold pressing, extrusion, injection molding, and the like can be applied. When using mold molding, a molding pressure of 200 kg / cm ² or more is desirable to increase the density of the sintered body. If the molding pressure is lower than this, the relative density of the sintered body is low, and the heat capacity per unit volume is reduced.

【００２４】焼成は非酸化ガス中で行われる脱脂の熱処
理に続けて真空中または不活性ガス中、１３００〜１８
００℃で１〜４時間保持することによって行われる。た
だし、脱脂の熱処理後、一度室温まで降温したのち再度
昇温し焼成してもよい。The calcination is carried out in a vacuum or in an inert gas at 1300 to 18 after the heat treatment for degreasing performed in a non-oxidizing gas.
It is performed by holding at 00 ° C. for 1 to 4 hours. However, after the heat treatment for degreasing, the temperature may be once lowered to room temperature, then raised again and fired.

【００２５】得られた焼結体の両主面を研磨し、溶射，
焼き付け、スパッタリングなどの手段により一対の電極
を形成する。この電極は、アルミニウムまたはニッケル
などから構成することが望ましい。The two main surfaces of the obtained sintered body are polished,
A pair of electrodes is formed by means such as baking or sputtering. This electrode is preferably made of aluminum or nickel.

【００２６】この後、前記焼結体の外周面および中空部
の内周面に所望により、酸化アルミニウム、酸化ケイ
素、ホウ珪酸ガラスの如き絶縁性セラミック、またはポ
リイミドのような樹脂を焼き付け、溶射または塗布、乾
燥等により絶縁層を形成して抵抗体を製造する。Thereafter, an insulating ceramic such as aluminum oxide, silicon oxide or borosilicate glass, or a resin such as polyimide is baked on the outer peripheral surface of the sintered body and the inner peripheral surface of the hollow portion, if desired, and sprayed or sprayed. An insulating layer is formed by coating, drying and the like to manufacture a resistor.

【００２７】なお、バインダ添加後に得られる凝集粉末
に含まれる水分含有量は７重量％以上、１５重量％以下
が好ましい。上記水分含有量が７重量％未満であると、
凝集粒子の緻密性に欠け、１５重量％以上であると、造
粒粒子が緻密になり過ぎ、粒子が硬すぎて良好な成型体
が出来ず、本発明の効果が失われる。前記第１の領域と
前記第２の領域の接合部において、相互に接する長さが
断面上で第２領域周囲長の５０％を超えないことが好ま
しい。相互に接する長さが断面上で第２領域周囲長の５
０％を以上を示す部分があると第２の領域間の電気的な
接続が不均一になり、エネルギー吸収耐量の低下をきた
す。なお、第２の造粒粉末の平均粒子径は第１の造粒粉
末の平均粒子径よりも小さくしてもよい。この場合、第
２の造粒粉末の混合割合は第１及び第２の造粒粉末の平
均粒子径が等しい場合に比べ、小さくすることができ
る。The water content in the agglomerated powder obtained after the addition of the binder is preferably from 7% by weight to 15% by weight. When the water content is less than 7% by weight,
If the density of the aggregated particles is insufficient, and if the content is 15% by weight or more, the granulated particles become too dense, the particles are too hard to form a good molded body, and the effect of the present invention is lost. It is preferable that the length of the junction between the first region and the second region does not exceed 50% of the peripheral length of the second region on the cross section. The length in contact with each other is 5 of the peripheral length of the second region on the cross section.
If there is a portion showing 0% or more, the electrical connection between the second regions becomes non-uniform, and the energy absorption resistance decreases. The average particle size of the second granulated powder may be smaller than the average particle size of the first granulated powder. In this case, the mixing ratio of the second granulated powder can be smaller than that in the case where the average particle diameters of the first and second granulated powders are equal.

【００２８】なお、本発明に係わる電力用抵抗体は、前
述した円板形状を有する構造に限定されない。例えば、
図５および図６に示すように環状の焼結体１１と、焼結
体１１の対抗する環状両面に形成された電極１２と、焼
結体１１の外周面および内周面に被覆された絶縁層１
３，１４とから電力用抵抗体１５を構成してもよい。The power resistor according to the present invention is not limited to the above-described disk-shaped structure. For example,
As shown in FIGS. 5 and 6, an annular sintered body 11, electrodes 12 formed on opposing annular surfaces of the sintered body 11, and an insulating material coated on the outer and inner peripheral surfaces of the sintered body 11. Tier 1
The power resistor 15 may be composed of the power resistors 3 and 14.

【００２９】また、本発明に係る電力用抵抗体を後述す
る電力用遮断器の投入抵抗体や高電圧装置、大容量コン
デンサの充放電装置等に用いられる固定抵抗器、可変抵
抗器、抵抗器アレーに適用することができる。Further, the power resistor according to the present invention is a fixed resistor, a variable resistor, and a resistor used for a closing resistor, a high-voltage device, a large-capacity capacitor charging / discharging device, etc. of a power circuit breaker described later. Can be applied to arrays.

【００３０】次に、本発明に係る電力用遮断器を図７お
よび図８を参照して説明する。図７は、本発明に係る遮
断器の構成図、図８は投入抵抗体を示す斜視図である。
遮断器２１は、消弧室２２内に配置され電流経路に接続
された主接点２３を備えている。補助接点２４は、電流
経路に接続された主接点２３に対して並列に接続されて
いる。投入抵抗ユニット２５は、補助接点２４に直列に
接続されている。上下動する絶縁ロッド２６は、傾動す
るレバー２７に連結されている。Next, a power circuit breaker according to the present invention will be described with reference to FIGS. FIG. 7 is a configuration diagram of a circuit breaker according to the present invention, and FIG. 8 is a perspective view showing a closing resistor.
The circuit breaker 21 has a main contact 23 arranged in the arc-extinguishing chamber 22 and connected to a current path. The auxiliary contact 24 is connected in parallel to the main contact 23 connected to the current path. The closing resistance unit 25 is connected to the auxiliary contact 24 in series. The insulating rod 26 that moves up and down is connected to a lever 27 that tilts.

【００３１】このような構成の電力用遮断器において、
前記絶縁ロッド２６が上方に駆動されると、主接点２３
のＯＮに先立って補助接点２４がＯＮされる。この際、
投入抵抗ユニット２５は補助接点２４に直列に接続され
ているため、補助接点２４が介装された電流経路を流れ
る電流は投入抵抗ユニット２５により制限されるととも
に、主接点２３がＯＮされる直前にかかる接点間の電圧
は、投入抵抗ユニットの抵抗値と線路インピーダンスと
で決まるより低い電圧に制限される。その結果、主接点
２３のＯＮ時にアークが発生するのを防止できる。In the power circuit breaker having such a configuration,
When the insulating rod 26 is driven upward, the main contact 23
The auxiliary contact 24 is turned on prior to the turning on of. On this occasion,
Since the closing resistance unit 25 is connected in series to the auxiliary contact 24, the current flowing through the current path in which the auxiliary contact 24 is interposed is limited by the closing resistance unit 25 and immediately before the main contact 23 is turned ON. The voltage between the contacts is limited to a lower voltage determined by the resistance value of the closing resistance unit and the line impedance. As a result, it is possible to prevent an arc from being generated when the main contact 23 is turned on.

【００３２】投入抵抗ユニット２５は、例えば図８に示
すような主に絶縁性支持棒２８と、一対の絶縁性支持板
２９ａ，２９ｂと、複数の中空円筒状の抵抗体３０と、
弾性体３１とから構成されている。一対の絶縁性支持板
２９ａ，２９ｂは、支持棒２８に嵌入されている。複数
の中空円筒状の抵抗体３０は、支持板２９ａ，２９ｂ間
に位置する支持棒２８部分に嵌入されている。弾性体３
１は、一方（右端）の支持板２９ａと複数の抵抗体３０
の間に配置されるとともに、支持棒２８に嵌入されてい
る。弾性体３１は、複数の抵抗体３０に弾性力を付与し
てそれらを支持棒２８に積層するために用いられる。ナ
ット３２ａ，３２ｂは、支持棒２８の両端に螺合されて
いる。ナット３２ａ，３２ｂは支持板２９ａ，２９ｂ間
に配置された弾性体３１を押圧するために用いられる。
絶縁性支持棒２８は高強度、軽量化、易加工性、などの
理由から有機系の材料が用いられる。一般に、投入抵抗
体は開閉サージ吸収時に温度上昇を生じる。このため、
耐熱性が劣る有機系材料からなる支持棒は強度維持する
ことが困難になる。ただし、後述する組成の投入抵抗体
は熱容量が大きいために開閉サージ吸収時における温度
上昇を一定温度以下に抑制することが可能になる。その
結果、有機系材料からなる支持棒の使用が可能になる。
また、熱容量の大きな投入抵抗体ほど遮断器の容積を小
さくすることが可能になる。The closing resistance unit 25 mainly includes an insulating support rod 28, a pair of insulating support plates 29a and 29b, a plurality of hollow cylindrical resistors 30 as shown in FIG.
And an elastic body 31. The pair of insulating support plates 29a and 29b are fitted into the support rod 28. The plurality of hollow cylindrical resistors 30 are fitted into support rods 28 located between support plates 29a and 29b. Elastic body 3
1 is one (right end) support plate 29a and a plurality of resistors 30
And fitted into the support rod 28. The elastic body 31 is used for applying an elastic force to the plurality of resistors 30 and stacking them on the support rod 28. The nuts 32 a and 32 b are screwed to both ends of the support rod 28. The nuts 32a and 32b are used to press the elastic body 31 disposed between the support plates 29a and 29b.
The insulating support rod 28 is made of an organic material for reasons such as high strength, light weight, and easy workability. Generally, the temperature of the closing resistor increases when the switching surge is absorbed. For this reason,
It is difficult to maintain the strength of a support rod made of an organic material having poor heat resistance. However, since the input resistor having a composition described later has a large heat capacity, it is possible to suppress a temperature rise during absorption of the switching surge to a certain temperature or less. As a result, it is possible to use a support rod made of an organic material.
Further, the capacity of the circuit breaker can be reduced as the input resistor has a larger heat capacity.

【００３３】投入抵抗ユニット２５に組み込まれた抵抗
体（電力用抵抗体）３０は、前述した図４および図５に
示すように環状の焼結体１１と、焼結体１１の環状両面
に形成された一対の電極１２と、焼結体１１の外周面お
よび内周面に被覆された絶縁層１３，１４とから構成さ
れている。The resistor (power resistor) 30 incorporated in the closing resistor unit 25 is formed on the annular sintered body 11 as shown in FIG. 4 and FIG. And a pair of electrodes 12 and insulating layers 13 and 14 which cover the outer and inner peripheral surfaces of the sintered body 11.

【００３４】上述したように本実施の形態にかかる電力
用遮断器は、前述した構成の焼結体を含み、単位体積あ
たりの熱容量が大きく、経時的な抵抗値変動が小さく、
かつ所期目的の抵抗値を有する抵抗体が組み込まれた投
入抵抗ユニットを備えている。このような投入抵抗ユニ
ットは、遮断容量が大きく、従来のカーボン分散型セラ
ミック抵抗体が組み込まれた投入抵抗ユニットに比べて
容積を小さくでき、さらに安定した遮断性能を有する。
従って、前記投入抵抗ユニットを備えた電力用遮断器は
小型化および高性能化をはかることができる。その他、
本発明はその要旨を逸脱しない範囲で種々変形して実施
できる。As described above, the power circuit breaker according to the present embodiment includes the sintered body having the above-described configuration, has a large heat capacity per unit volume, a small variation in resistance value with time,
Further, there is provided a closing resistance unit in which a resistor having an intended resistance value is incorporated. Such a closing resistor unit has a large breaking capacity, can have a smaller volume than a closing resistor unit in which a conventional carbon dispersed ceramic resistor is incorporated, and has more stable breaking performance.
Therefore, the power circuit breaker provided with the closing resistance unit can be reduced in size and improved in performance. Others
The present invention can be implemented with various modifications without departing from the scope of the invention.

【００３５】[0035]

【実施例】以下、本発明の実施例について説明する。 実施例１〜４ 本発明の電力用抵抗体は以下の様に製造された。Embodiments of the present invention will be described below. Examples 1 to 4 A power resistor according to the present invention was manufactured as follows.

【００３６】平均粒径０．５μｍの酸化アルミニウム原
料粉末にＳｉＯ² 、ＭｇＯ、ＣａＯを成分とする焼結助
剤粉末を１重量％を加え、混合容器中で攪拌ピンを備え
た回転軸を５０００回／分で回転させ、粉体に衝撃を与
えながら乾燥状態で１０分間混合したのち、引き続きバ
インダーとしてパラフインを水に分散させたエマルジョ
ン溶液をパラフインが固形分として５重量部に相当する
ようスプレーノズルより高速攪拌中の粉体に注入し、注
入後さらに１０分間の攪拌を行い、凝集粉末を得た。こ
こに、バインダー液のパラフィン濃度を適宜選択し、凝
集粉末に含有する水分量が５重量％から２０重量％まで
それぞれ変化させた。さらに得られた混合粉末を乾燥
後、目開き２００μｍのメッシュを通過させ、第１の造
粒粉末を得た。また、第１の造粒粉末に使用したものと
同じ酸化アルミニウム粉末を出発原料として、平均粒子
径が５０ｎｍのカーボン粉末を２重量％添加し、第１の
造粒粉末と同様にして第２の造粒粉末を得た。第１の造
粒粉末に対して第２の造粒粉末をそれぞれ２０重量％の
割合でＶ型混合器により軽い攪拌混合を行い、混合造粒
粉末を得た。To a powder of aluminum oxide having an average particle size of 0.5 μm, 1% by weight of a sintering aid powder containing SiO ² , MgO, and CaO was added, and a rotating shaft equipped with a stirring pin was set to 5000 in a mixing vessel. After spinning the powder at 10 times / minute and mixing the powder in a dry state for 10 minutes while applying an impact to the powder, then spray the emulsion solution in which paraffin is dispersed in water as a binder so that the paraffin corresponds to 5 parts by weight as a solid content. The powder was injected into the powder being stirred at a higher speed, and the mixture was further stirred for 10 minutes after the injection to obtain an aggregated powder. Here, the paraffin concentration of the binder liquid was appropriately selected, and the amount of water contained in the aggregated powder was changed from 5% by weight to 20% by weight. Further, after the obtained mixed powder was dried, it was passed through a mesh having an opening of 200 μm to obtain a first granulated powder. Further, starting from the same aluminum oxide powder as that used for the first granulated powder, 2% by weight of carbon powder having an average particle diameter of 50 nm was added, and the second powder was prepared in the same manner as the first granulated powder. A granulated powder was obtained. The first granulated powder and the second granulated powder were each lightly stirred and mixed at a ratio of 20% by weight using a V-type mixer to obtain a mixed granulated powder.

【００３７】これらの混合造粒粉末は鋼鉄製金型を用い
てシリンダ型の円板状に成形され、窒素中６００℃の脱
脂過程を経て、アルゴン中１５００℃で２時間の焼成を
行った。この焼結体の側面に、ホウケイ酸ガラス粉末を
塗布、焼き付けて絶縁層を形成した。その後、この焼結
体の両端面を研削後、外径１２０ｍｍ、内径３５ｍｍ、
高さ２５ｍｍの寸法とし、両端面にアルミニウム電極を
溶射により形成して、比較例とあわせ６種の抵抗素子を
得た。These mixed granulated powders were formed into cylinder-shaped discs using a steel mold, baked in nitrogen at 600 ° C., and then in argon at 1500 ° C. for 2 hours. Borosilicate glass powder was applied to the side surface of the sintered body and baked to form an insulating layer. Then, after grinding both end surfaces of this sintered body, an outer diameter of 120 mm, an inner diameter of 35 mm,
Aluminum electrodes were formed on both end surfaces by thermal spraying to have a height of 25 mm, and six types of resistance elements were obtained together with the comparative example.

【００３８】また、それぞれの造粒粉末を得る方法とし
て、カーボン含有量の異なる第１の混合粉末と第２の混
合粉末とをそれぞれ有機溶媒、成型用バインダーととも
に混合し、スラリー化し、スプレードライヤー等を用い
て、溶媒を除去することにより、第１の造粒粉末及び第
２の造粒粉末とし、以下、上記実施例と同様な方法で比
較例の抵抗素子を得た。表１に抵抗率、素子内および素
子間の抵抗比を比較例とあわせて示した。As a method for obtaining each of the granulated powders, a first mixed powder and a second mixed powder having different carbon contents are mixed together with an organic solvent and a molding binder to form a slurry. Then, the solvent was removed to obtain a first granulated powder and a second granulated powder, and thereafter, a resistance element of a comparative example was obtained in the same manner as in the above example. Table 1 shows the resistivity, the resistance ratio within the element and between the elements, together with the comparative example.

【００３９】[0039]

【表１】 [Table 1]

【００４０】抵抗素子の製造安定性を調べるために、同
一ロットの抵抗素子２０個の抵抗値を測定し、その最大
値と最小値の比を素子間抵抗比とした。また、焼結体内
部の抵抗率の均一性を評価するために、抵抗素子の一方
の面の電極を除去し、直径３ｍｍのアルミニウム電極を
２０個、溶射により電極面に均等に配置、形成した。こ
れらの電極と他方の面の電極との間の抵抗を測定し、そ
の最大値と最小値の比を素子内抵抗比とした。実用上、
素子間抵抗比は５以下が好ましく、素子内抵抗分布は１
０以下が好ましい。In order to examine the manufacturing stability of the resistance elements, the resistance values of 20 resistance elements of the same lot were measured, and the ratio between the maximum value and the minimum value was defined as the resistance ratio between the elements. Further, in order to evaluate the uniformity of the resistivity inside the sintered body, the electrode on one surface of the resistance element was removed, and 20 aluminum electrodes having a diameter of 3 mm were uniformly arranged and formed on the electrode surface by thermal spraying. . The resistance between these electrodes and the electrode on the other surface was measured, and the ratio between the maximum value and the minimum value was defined as the in-element resistance ratio. In practice,
The resistance ratio between elements is preferably 5 or less, and the resistance distribution in the element is 1
0 or less is preferable.

【００４１】エネルギー吸収耐量の良否を比較するため
に、同一ロットの抵抗素子２０個にそれぞれ４００Ｊ／
ｃｍ³ のエネルギーに相当するサージ電圧を素子冷却を
考慮した一定間隔の時間をおいて１０回繰り返し印加
し、発生した抵抗変化を初期値に対する百分率で示し
た。抵抗変化率が１０％以下の素子の割合の百分率を歩
留りとし、表１にあわせて示した。In order to compare the quality of the energy absorption tolerance, 20 J / resistance elements of the same lot were charged with 400 J /
A surge voltage corresponding to an energy of cm ³ was repeatedly applied 10 times at regular intervals in consideration of element cooling, and the generated resistance change was expressed as a percentage of an initial value. The percentage of the ratio of the element having a resistance change rate of 10% or less is defined as the yield, and is shown in Table 1.

【００４２】表１によれば、高速で回転するピンの衝撃
により乾燥状態で混合し、攪拌しながらバインダを加え
た混合および造粒工程を備えた抵抗体において、抵抗率
が１０３Ω・ｃｍを超える場合においても、素子内抵抗
比は１０以下の値を示し、均一性に優れるとともに、素
子間抵抗比も５以下であり、安定に製造できることが明
らかである。また、バインダ添加後に得られる凝集粉末
に含まれる水分含有量は７重量％以上、１５重量％以下
で抵抗分布の均一性に優れ、素子間ばらつきも十分小さ
く、良好なエネルギー吸収耐量を示すものであった。な
お、混合に溶媒を用い、乾燥・造粒にスプレードライヤ
ーを用いた比較例３の場合と第１および第２の領域構造
を持たない比較例４の場合には、均一な抵抗体が得られ
にくくなるとともに、製造安定性に劣るものであった。According to Table 1, in a resistor provided with a mixing and granulating process in which a binder is added while stirring and mixing in a dry state by the impact of a pin rotating at high speed, the resistivity exceeds 103 Ω · cm. Also in this case, the resistance ratio in the element shows a value of 10 or less, which is excellent in uniformity, and the resistance ratio between the elements is 5 or less. Further, the moisture content contained in the aggregated powder obtained after the addition of the binder is 7% by weight or more and 15% by weight or less, the resistance distribution is excellent in uniformity, the variation between elements is sufficiently small, and a good energy absorption resistance is exhibited. there were. In the case of Comparative Example 3 in which a solvent was used for mixing and a spray dryer was used for drying and granulation, and in the case of Comparative Example 4 having no first and second region structures, a uniform resistor was obtained. However, the production stability was poor.

【００４３】なお、本発明抵抗体の相対密度は９２％以
上と緻密に焼結されているため、熱容量はほぼ３Ｊ／ｃ
ｍ³ と大きな値を有しており、電力用抵抗体として好適
である。Since the resistor of the present invention is densely sintered at a relative density of 92% or more, its heat capacity is approximately 3 J / c.
It has a large value of m ³ and is suitable as a power resistor.

【００４４】本発明により得られた抵抗体において、透
過型電子顕微鏡で観察した焼結体の微構造を図１に示
す。カーボン粒子は第１の領域にはほとんど見られず、
第２の領域に多く見られ、領域構造を示していることが
わかる。第２の領域の酸化アルミニウムの粒径は０．３
〜１μｍと非常にこまかく、また、カーボン粒子は酸化
アルミニウム粒子の粒界の会合部（３重点）に平均粒子
径５０ｎｍ程度の粒子が多数集まった構造をしており、
このような構造が電流経路となるカーボン粒子同志の接
続を安定に形成しているものと考えられる。また、第１
の領域に見られる様に酸化アルミニウムの粒子は１〜５
μｍと粒成長しており、緻密であり、このような領域構
造にすることにより、カーボンを含むことで難焼結性と
なる酸化アルミニウムに対して焼結性を向上させている
ことがわかる。さらに混合時に溶媒を用い、スプレード
ライ造粒を用いた抵抗素子は造粒粉粒径が比較的揃って
いるが、中空状態の粒子が含まれていることが多く、図
４のように第２の領域が第１の領域に覆われた断面構
造、すなわち第１の領域と前記第２の領域の接合部にお
いて、相互に接する長さが断面上で領域周囲長の５０％
以上を示す部分があり、第２の領域間の電気的な接続が
不均一であり、エネルギー吸収耐量の低下をきたしてい
る。FIG. 1 shows the microstructure of the sintered body of the resistor obtained according to the present invention, observed by a transmission electron microscope. Carbon particles are hardly found in the first area,
It can be seen that it is often seen in the second region, indicating a region structure. The particle size of the aluminum oxide in the second region is 0.3
１1 μm, and the carbon particles have a structure in which a large number of particles having an average particle diameter of about 50 nm gathered at the junction (triple junction) of the grain boundaries of the aluminum oxide particles.
It is considered that such a structure stably forms a connection between carbon particles serving as a current path. Also, the first
The aluminum oxide particles are 1 to 5 as seen in the region of
It can be seen that the grains have a grain growth of μm and are dense, and that such a region structure improves the sinterability of aluminum oxide, which becomes difficult to be sintered by containing carbon. Furthermore, although the resistance element using spray drying granulation using a solvent at the time of mixing has a relatively uniform granulated powder particle diameter, it often contains particles in a hollow state, and as shown in FIG. In the cross-sectional structure in which the region is covered by the first region, that is, at the junction between the first region and the second region, the length in contact with each other is 50% of the region peripheral length on the cross section.
There is a portion showing the above, and the electrical connection between the second regions is non-uniform, resulting in a decrease in energy absorption resistance.

【００４５】実施例５〜８ （遮断器の評価例）前述した実施例１〜４および比較例
３〜４の電力用抵抗体を前述した図８に示すように所定
枚数積み重ね、各抵抗体３０の中心部を貫通する樹脂か
らなる絶縁性２８と弾性体３１により支持し、円筒状容
器に収めて投入抵抗ユニット２５を構成した。これら投
入抵抗ユニットを前述した図７に示すように組み込んで
電力用遮断器４１を組み立てた。得られた電力用遮断器
について、それらの投入抵抗体に脱調投入し、抵抗体の
温度上昇が１００℃以内になるときの抵抗体に注入可能
なエネルギー（エネルギー耐量）を測定した。これらの
結果を表２に示す。Examples 5 to 8 (Evaluation Examples of Circuit Breakers) A predetermined number of the power resistors of Examples 1 to 4 and Comparative Examples 3 to 4 are stacked as shown in FIG. Are supported by an insulating body 28 made of resin and an elastic body 31 penetrating through the center portion of the core, and are housed in a cylindrical container to constitute a closing resistance unit 25. The power breaker 41 was assembled by incorporating these closing resistance units as shown in FIG. The obtained power circuit breakers were stepped into the input resistors, and the energy (energy tolerance) that could be injected into the resistors when the temperature rise of the resistors was within 100 ° C. was measured. Table 2 shows the results.

【００４６】[0046]

【表２】 [Table 2]

【００４７】高速で回転するピンの衝撃により乾燥状態
で混合し、攪拌しながらバインダを加えた混合および造
粒工程を備えた抵抗体を用いた実施例１〜４において、
高いエネルギー吸収耐量を示し、同一エネルギーを処理
する場合には遮断器を小型化出来ることがわかる。ま
た、実施例１から４の電力用抵抗体を組み込んだ電力用
遮断器について、遮断性能の安定性を調べるために脱調
投入相当のエネルギーを２０回印加し、投入抵抗体の抵
抗率変化を測定しあわせて表２に示す。その結果、いず
れの電力用遮断器も抵抗率変化が１０％以下であり、十
分に遮断性能の安定性が高いことが確認された。In Examples 1 to 4 using a resistor provided with a mixing and granulating step in which mixing was performed in a dry state by the impact of a pin rotating at high speed and a binder was added while stirring,
It can be seen that the circuit breaker can be downsized when it shows a high energy absorption tolerance and processes the same energy. Further, with respect to the power circuit breaker incorporating the power resistors of Examples 1 to 4, in order to examine the stability of the breaking performance, energy equivalent to step-out input was applied 20 times, and the resistivity change of the input resistor was measured. Table 2 shows the measured values. As a result, each of the power circuit breakers had a change in resistivity of 10% or less, and it was confirmed that the stability of the breaking performance was sufficiently high.

【００４８】[0048]

【発明の効果】以上説明したように、本願第１の発明に
よれば、焼結体としては、カーボン含有量が少ないかも
しくはカーボンを含まない第１領域と、この第１領域よ
りカーボン含有量が多く、かつ一対の電極に繋がるよう
に配置された第２領域とを有し、かつ第１領域と第２領
域を形成する粉末をそれぞれ、乾燥状態で分散・混合す
る分散工程と、分散・混合中の粉末に溶液状のバインダ
を加えることにより凝集させる凝集工程と、水分を減少
させる乾燥工程と、粒子径を整え、第１及び第２造粒粉
末を調製するための分級工程を備えているので、焼結体
の緻密性および均一性を向上できることにより、単位体
積あたりの熱容量が大きく、適切かつ安定した電気抵抗
値を有し、サージ吸収による抵抗値の経時変化が小さ
く、抵抗の均一性に優れ、再現性よく製造できる電力用
抵抗体を提供できる。As described above, according to the first aspect of the present invention, the sintered body has a first region having a low carbon content or no carbon, and a carbon content higher than the first region. A dispersing step of dispersing and mixing the powders forming the first and second regions in a dry state, each of which has a second region arranged so as to be connected to the pair of electrodes, and A coagulation step of coagulating by adding a solution binder to the powder being mixed, a drying step of reducing the water content, and a classifying step of adjusting the particle diameter and preparing the first and second granulated powders are provided. Since the density and uniformity of the sintered body can be improved, the heat capacity per unit volume is large, it has an appropriate and stable electric resistance, the resistance change over time due to surge absorption is small, and the resistance is uniform. To sex It is possible to provide a power resistor which can be produced with good reproducibility.

【００４９】また、本願第２の発明によれば、前記凝集
工程後の粉末の水分含有量が７〜１５重量％の範囲にあ
るので、本願第１の発明の効果に加え、電力用抵抗体と
して好適な抵抗率と十分な緻密性とを確保できる電力用
抵抗体を提供できる。According to the second aspect of the present invention, since the water content of the powder after the aggregating step is in the range of 7 to 15% by weight, in addition to the effect of the first aspect of the present invention, As a result, it is possible to provide a power resistor that can secure a suitable resistivity and sufficient denseness.

【００５０】さらに、本願第３の発明によれば、前記第
１の領域と前記第２の領域の接合部において、相互に接
する長さが断面上で領域周囲長の５０％未満であるの
で、第２の領域どうしの電気的接続が均一に形成され、
容易に抵抗率を制御できるとともにサージエネルギーの
吸収に対して安定性の優れた電力用抵抗体を提供でき
る。Further, according to the third aspect of the present invention, the length of the junction between the first region and the second region is less than 50% of the peripheral length of the region on the cross-section. The electrical connection between the second regions is formed uniformly,
It is possible to provide a power resistor that can easily control the resistivity and has excellent stability against absorption of surge energy.

【００５１】また、本願第３の発明によれば、請求項１
に対応する焼結体からなる抵抗体を有しているので、遮
断容量が大きく、遮断性能の安定した投入抵抗ユニット
を備え、小型、高性能化を達成できる電力用遮断器を提
供できる。According to the third aspect of the present invention, claim 1 is provided.
Therefore, it is possible to provide a power circuit breaker having a closing resistance unit having a large breaking capacity and a stable breaking performance, and capable of achieving a small size and high performance.

【図面の簡単な説明】[Brief description of the drawings]

【図１】 本発明の実施の形態に係る電力用抵抗体の構
成を示す断面図FIG. 1 is a sectional view showing a configuration of a power resistor according to an embodiment of the present invention.

【図２】 同実施の形態における焼結体の微構造を模式
的に示す図FIG. 2 is a diagram schematically showing a microstructure of a sintered body according to the embodiment.

【図３】 同実施の形態における第２領域を拡大して模
式的に示す図FIG. 3 is a diagram schematically showing an enlarged second region in the embodiment.

【図４】 同比較の形態における焼結体の微構造のを模
式的に示す図FIG. 4 is a view schematically showing a microstructure of a sintered body according to the comparative example.

【図５】 本発明の他の実施の形態に係る電力用抵抗体
の構成を示す斜視図FIG. 5 is a perspective view showing a configuration of a power resistor according to another embodiment of the present invention.

【図６】 図５の電力用抵抗体のＶ−Ｖ線矢視断面図FIG. 6 is a cross-sectional view of the power resistor of FIG. 5 taken along line VV.

【図７】 本発明の実施の形態に係る電力用遮断器を示
す構成図FIG. 7 is a configuration diagram showing a power circuit breaker according to an embodiment of the present invention.

【図８】 同実施の形態における電力用遮断器の投入抵
抗ユニットを示す構成図FIG. 8 is a configuration diagram showing a closing resistance unit of the power circuit breaker according to the embodiment.

【符号の説明】[Explanation of symbols]

１、１５…抵抗体、 ２、１１…焼結体、 ３、１２…電極、 ４、１３，１４…側面絶縁層、 ５…第１領域、 ６…第２領域、 ８…酸化アルミニウム粒子、 ９…カーボン、 ２１…遮断器、 ２２…消弧室、 ２３…主接点、 ２４…補助接点、 ２５…投入抵抗体、 ２６…絶縁ロッド、 ２８…絶縁性支持棒、 ２９ａ，２９ｂ…絶縁性支持板、 ３０…抵抗体、 ３１…弾性体、 ３２ａ，３２ｂ…ナット。 Reference numerals 1, 15: resistor, 2, 11: sintered body, 3, 12: electrode, 4, 13, 14: side insulating layer, 5: first region, 6: second region, 8: aluminum oxide particles, 9 ... Carbon, 21 ... Circuit breaker, 22 ... Arc extinguishing chamber, 23 ... Main contact, 24 ... Auxiliary contact, 25 ... Closed resistor, 26 ... Insulating rod, 28 ... Insulating support rod, 29a, 29b ... Insulating support plate Reference numeral 30: resistor, 31: elastic body, 32a, 32b: nut.

Claims (4)

【特許請求の範囲】[Claims] 【請求項１】 酸化アルミニウムを主体とする第１の粉
末を、乾燥状態で分散・混合する分散工程と、 分散・混合中の第１の粉末に溶液状のペーストを加え、
第１の粉末を凝集させる凝集工程と、 凝集された第１の粉末を乾燥させる工程と、 乾燥された第１の粉末を分級し、第１の造粒粉を得る工
程と、 第１の粉末よりカーボンを多量に含有する、酸化アルミ
ニウムおよびカーボンを含有する第２の粉末を、乾燥状
態で分散・混合する工程と、 分散・混合中の第２の粉末に溶液状のペーストを加え、
第２の粉末を凝集させる工程と、 凝集された第２の粉末を乾燥させる工程と、 乾燥された第２の粉末を分級し、第２の造粒粉を得る工
程と、 前記第１および第２の造粒粉を混合、成形、焼結し、酸
化アルミニウムを主体とする第１の領域と、第１の領域
よりカーボン含有量の多い第２の領域とからなる焼結体
を製造する工程と、 前記焼結体の対向する面に一対の電極を形成する工程と
を有することを特徴とする電力用抵抗体の製造方法。1. A dispersion step of dispersing and mixing a first powder mainly composed of aluminum oxide in a dry state, and adding a solution paste to the first powder being dispersed and mixed,
An aggregating step of aggregating the first powder; a step of drying the agglomerated first powder; a step of classifying the dried first powder to obtain a first granulated powder; A step of dispersing and mixing the second powder containing aluminum oxide and carbon in a dry state, containing a larger amount of carbon, and adding a solution paste to the second powder being dispersed and mixed,
Aggregating the second powder; drying the agglomerated second powder; classifying the dried second powder to obtain a second granulated powder; Mixing, molding and sintering the granulated powder of No. 2 to produce a sintered body comprising a first region mainly composed of aluminum oxide and a second region having a higher carbon content than the first region. And a step of forming a pair of electrodes on opposing surfaces of the sintered body. 【請求項２】 前記第１あるいは第２の粉末を凝集させ
る工程は、凝集された前記第１あるいは第２の粉末中の
水分含有量を７〜１５重量％の範囲にすることを特徴と
する請求項１記載の電力用抵抗体の製造方法。2. The step of aggregating the first or second powder, wherein the water content in the agglomerated first or second powder is in the range of 7 to 15% by weight. A method for manufacturing a power resistor according to claim 1. 【請求項３】 酸化アルミニウム及びカーボンを含む焼
結体と、この焼結体の対向する面に形成された一対の電
極とを具備し、前記焼結体はカーボン含有量が少ないか
もしくはカーボンを含まない第１領域と、この第１領域
よりもカーボン含有量が多く、かつ前記電極に電気的に
接続される第２の領域とを有する電力用抵抗体におい
て、 前記第１の領域と第２の領域の接合部が、相互に接する
長さが断面上で領域周囲長の５０％未満であることを特
徴とする電力用抵抗体。3. A sintered body containing aluminum oxide and carbon, and a pair of electrodes formed on opposing surfaces of the sintered body, wherein the sintered body has a low carbon content or contains carbon. A first region that does not include the first region and a second region that has a higher carbon content than the first region and that is electrically connected to the electrode; A power resistor characterized in that the length of contact between the junctions in the region is less than 50% of the region perimeter on the cross section. 【請求項４】 電流経路に配置される主開閉手段と、前
記電流経路に前記主開閉手段に対して電気的に並列に接
続され、前記主開閉手段の閉状態への切り替えよりも先
行して閉状態に切替えられる補助開閉手段と、前記補助
開閉手段に電気的に直列に接続された前期生急行３に記
載の電力用抵抗体とを有することを特徴とする電力用遮
断器。4. A main switching means arranged in a current path, and electrically connected in parallel to said main switching means in said current path, prior to switching of said main switching means to a closed state. A power circuit breaker, comprising: an auxiliary switching device that is switched to a closed state; and a power resistor according to the third embodiment, electrically connected to the auxiliary switching device in series.