JPH11345685A - Nipple for electrode - Google Patents
Nipple for electrodeInfo
- Publication number
- JPH11345685A JPH11345685A JP10155525A JP15552598A JPH11345685A JP H11345685 A JPH11345685 A JP H11345685A JP 10155525 A JP10155525 A JP 10155525A JP 15552598 A JP15552598 A JP 15552598A JP H11345685 A JPH11345685 A JP H11345685A
- Authority
- JP
- Japan
- Prior art keywords
- nipple
- electrode
- socket
- groove
- face
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/25—Process efficiency
Landscapes
- Discharge Heating (AREA)
Abstract
Description
【0001】[0001]
【産業上の利用分野】本発明は、電極用ニップル、詳し
くは、電気製鋼炉用黒鉛電極を相互に接続し、電気製鋼
炉の操業中において、黒鉛電極の接続部の破損を防止す
るための電極用ニップルの改良に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nipple for an electrode, and more particularly, to a graphite electrode for an electric steelmaking furnace, which is connected to each other so as to prevent breakage of a connecting portion of the graphite electrode during the operation of the electric steelmaking furnace. It relates to improvement of nipples for electrodes.
【0002】[0002]
【従来の技術】電気製鋼炉においては黒鉛電極が使用さ
れ、電極先端と炉内に装入された製鋼原料との間にアー
クを飛ばして原料を溶解する。黒鉛電極はアークによ
り、例えば3000℃にも達するため消耗が激しく、そ
の消耗を補うため、一般には、黒鉛電極を炉外上部から
順次接続して補給している。2. Description of the Related Art In an electric steelmaking furnace, a graphite electrode is used, and an arc is blown between the tip of the electrode and a steelmaking raw material charged in the furnace to melt the raw material. The graphite electrode is greatly consumed because it reaches, for example, 3000 ° C. due to the arc. In order to compensate for the exhaustion, the graphite electrode is generally connected sequentially from the upper part outside the furnace and replenished.
【0003】黒鉛電極の接続は、図4に示すように、電
極ポール1の両端部にテーパー状のソケット(雌ねじ
部)2を形成し、ソケット2に、両端部に向けてテーパ
ーを付け、テーパー部に雄ねじ部を形成したニップル
(黒鉛継手)3を螺入することにより行われる。As shown in FIG. 4, a graphite electrode is connected by forming tapered sockets (female screw portions) 2 at both ends of an electrode pole 1 and tapering the socket 2 toward both ends. This is performed by screwing a nipple (graphite joint) 3 having a male screw portion formed in the portion.
【0004】このように連結された黒鉛電極の接続部は
強度が弱いため、操業中、原料スクラップの崩れ落ちな
どにより衝撃(機械的応力)が負荷されると、ソケット
のねじ山谷底部、とくに応力集中の大きいニップルとソ
ケットの螺合部の終端部(図5のA部)が起点となって
折損が生じることが経験されている。[0004] Since the connecting portions of the graphite electrodes connected in this way have low strength, if an impact (mechanical stress) is applied during operation due to the collapse of raw material scrap, etc., the bottom of the thread valley of the socket, particularly the stress concentration, will occur. It has been experienced that the end portion of the threaded portion between the nipple and the socket having a large diameter (portion A in FIG. 5) is a starting point and breakage occurs.
【0005】また、とくに大径の電極においては、半径
方向に温度差が生じ易く、熱応力による電極破損も問題
となる。電極の接続部においては、ニップルは電極ポー
ルに比べて大幅に温度が高くなり、電極ポールより熱膨
張係数が大きいこともあって、内部に位置するニップル
が熱膨張してソケット部を破壊する破損事故が発生する
ことがある。[0005] In particular, in the case of a large-diameter electrode, a temperature difference easily occurs in the radial direction, and there is a problem that the electrode is damaged by thermal stress. At the electrode connection, the nipple has a much higher temperature than the electrode pole, and has a larger coefficient of thermal expansion than the electrode pole, so the nipple located inside expands thermally and breaks the socket. Accidents may occur.
【0006】接続部が操業中に破損すると、その下部の
電極が溶鋼中に落下して作業を遅延させ、ときには炉の
操業を休止させることもあって生産性を低下させ、また
落下した電極が溶鋼中に混入して鋼の品質を劣化させる
などの問題が生じるため、電極の折損事故を防止するた
めに、電極接続部の改良について、これまで多くの提案
がなされている。If the connection is broken during operation, the lower electrode falls into the molten steel, delaying the operation, and sometimes stopping the operation of the furnace, thereby lowering the productivity. Since problems such as deterioration of steel quality due to mixing in molten steel occur, many proposals have been made on improvement of electrode connection portions in order to prevent electrode breakage accidents.
【0007】例えば、機械的応力に基づく電極接続部の
破損を防止するために、図6に示すように、ニップル3
の端部に、その直径の50〜80%の径を有する肉ぬす
み部9を設けるとともに、この肉ぬすみ部9を電極ポー
ル1のソケット2の底部に螺合する構造の電極継手が提
案されている。(実公昭56−7115号公報)この構
造のものは、ニップルとソケットの螺合部の終端部の応
力集中を緩和し、電極の長さ方向に直角な面に生じる割
れ(横割れ)を防止するのにかなり有効であるが、最近
のように、電気炉を複数設けて交互に操業を行う方式で
は、黒鉛電極の加熱冷却サイクルが頻繁に行われる関係
から十分な対策とはなっていない。For example, as shown in FIG. 6, a nipple 3 is provided to prevent breakage of an electrode connection due to mechanical stress.
An electrode joint having a structure in which a thin portion 9 having a diameter of 50 to 80% of the diameter thereof is provided at an end portion thereof and the thin portion 9 is screwed to the bottom of the socket 2 of the electrode pole 1 has been proposed. I have. (Japanese Utility Model Publication No. 56-7115) This structure reduces the stress concentration at the end of the threaded portion of the nipple and the socket, and prevents cracks (lateral cracks) occurring on the surface perpendicular to the length direction of the electrode. Although this method is quite effective, a method of providing a plurality of electric furnaces and operating them alternately, as in recent years, has not been a sufficient measure due to the frequent heating and cooling cycles of the graphite electrode.
【0008】熱応力による電極破損を防止するために、
図7に示すように、ニップル3の端面から長手方向に切
込み溝10を設けることも提案されている。(実公昭5
9−1357号公報)この構造は、電極接続部の円周方
向の熱応力を緩和し、長さ方向に対して平行な面に生じ
る割れ(縦割れ)を防止するには有効であるが、電極の
長さ方向に直角な面に生じる横割れを防止するには効果
がない。In order to prevent electrode damage due to thermal stress,
As shown in FIG. 7, it has also been proposed to provide a cut groove 10 in the longitudinal direction from the end face of the nipple 3. (Jun 5
This structure is effective in relieving thermal stress in the circumferential direction of the electrode connecting portion and preventing cracks (longitudinal cracks) generated on a plane parallel to the length direction. There is no effect in preventing a lateral crack occurring on a surface perpendicular to the length direction of the electrode.
【0009】図8、図9に示すように、ニップル3の端
面3Aと対向するソケット2の底面に、ソケット3のテ
ーパー面と連続した球面を有する空所11を設け、且つ
ニップル3の端面3Aからその内部に向けて斜めの切り
溝12を複数本設けるものも提案されている。(実公昭
62−24957号公報)As shown in FIGS. 8 and 9, a cavity 11 having a spherical surface continuous with the tapered surface of the socket 3 is provided on the bottom surface of the socket 2 facing the end surface 3A of the nipple 3, and the end surface 3A of the nipple 3. There is also proposed a device in which a plurality of oblique cut grooves 12 are provided toward the inside. (Japanese Patent Publication No. 62-24957)
【0010】この構造は、電極接続部で発生した応力を
切り溝12および空所11で吸収、分散させて、電極ポ
ールの折損を防止することを目的とするものであるが、
この構造においても、電極の長さ方向に直角な面に生じ
る横割れを防止するには不十分である。The purpose of this structure is to prevent the breakage of the electrode pole by absorbing and dispersing the stress generated at the electrode connecting portion in the kerf 12 and the space 11.
This structure is also insufficient to prevent lateral cracks occurring on a surface perpendicular to the length direction of the electrode.
【0011】発明者らは、電気製鋼炉に使用する黒鉛電
極の接続部における上記従来の問題点を解消できる接続
構造を開発するために、従来から提案されているニップ
ルの構造について再検討を加えた結果、ソケットの底面
に対向するニップルの端面に肉ぬすみ部9(図6)を設
ける構造が、肉ぬすみ部の形状によっては、電極の長さ
方向に直角な面に生じる横割れの防止のみでなく縦割れ
の防止に対しても有効に機能し得ることを見出した。The present inventors reexamined the structure of a nipple that has been conventionally proposed in order to develop a connection structure that can solve the above-mentioned conventional problems in the connection portion of a graphite electrode used in an electric steelmaking furnace. As a result, the structure in which the underfill 9 (FIG. 6) is provided on the end face of the nipple facing the bottom surface of the socket may only prevent lateral cracks generated on a surface perpendicular to the longitudinal direction of the electrode depending on the shape of the underfill. In addition, it has been found that it can function effectively to prevent vertical cracks.
【0012】[0012]
【発明が解決しようとする課題】本発明は、上記の知見
に基づいて、肉むすみ部の形状と割れ発生との関連につ
いてさらに実験、検討を重ねた結果としてなされたもの
であり、その目的は、ニップルとソケットの螺合部の終
端部に生じる応力を緩和するとともに、ニップルとソケ
ットの熱膨張差を吸収して、電極の横割れおよび縦割れ
を効果的に防止することを可能とする電気製鋼炉用黒鉛
電極の電極用ニップルを提供することにある。SUMMARY OF THE INVENTION The present invention has been made based on the above findings, as a result of repeated experiments and studies on the relationship between the shape of a dull portion and the occurrence of cracks. Can reduce the stress generated at the end of the threaded portion between the nipple and the socket, absorb the difference in thermal expansion between the nipple and the socket, and effectively prevent lateral cracks and longitudinal cracks of the electrode. An object of the present invention is to provide a nipple for an electrode of a graphite electrode for an electric steelmaking furnace.
【0013】[0013]
【課題を解決するための手段】上記の目的を達成するた
めの本発明による電極用ニップルは、電極ポールの端部
に形成したソケットに螺入して電極ポールを相互に接続
する電気製鋼炉用黒鉛電極のニップルにおいて、ソケッ
トに螺入したときソケットの底面と対向するニップルの
円形端面に溝部が周設され、該溝部とニップルの端部側
面とによって立ち上がり周壁部が形成されていることを
第1の特徴とする。A nipple for an electrode according to the present invention for achieving the above object is provided for an electric steelmaking furnace for connecting an electrode pole to each other by screwing into a socket formed at an end of the electrode pole. In the nipple of the graphite electrode, a groove is provided on the circular end surface of the nipple facing the bottom surface of the socket when screwed into the socket, and a rising peripheral wall portion is formed by the groove and the end side surface of the nipple. This is the feature of 1.
【0014】また、電極ポールの端部に形成したソケッ
トに螺入して電極ポールを相互に接続する電気製鋼炉用
黒鉛電極のニップルにおいて、ソケットに螺入したとき
ソケットの底面と対向するニップルの円形端面に溝部が
周設され、該溝部とニップルの端部側面との間が円形端
面の直径の1〜30%の端面肉厚を有する立ち上がり周
壁部に形成されていることを第2の特徴とする。A nipple of a graphite electrode for an electric steelmaking furnace, which is screwed into a socket formed at the end of the electrode pole to connect the electrode pole to each other, wherein the nipple is opposed to the bottom surface of the socket when screwed into the socket. A second feature is that a groove is formed around the circular end face, and a space between the groove and the end side face of the nipple is formed on a rising peripheral wall having an end face thickness of 1 to 30% of the diameter of the circular end face. And
【0015】さらに、上記の構造において、周壁部が連
続して形成されていること、および周壁部の1個所また
は複数個所に切欠きが形成されていることを第3および
第4の特徴とする。Further, in the above structure, the third and fourth features are that the peripheral wall portion is formed continuously, and that one or more notches are formed in the peripheral wall portion. .
【0016】[0016]
【発明の実施の形態】本発明の実施の形態を図面によっ
て説明する。なお、従来技術と同じ部材については同一
の符号を付した。本発明においては、図1、図2に示す
ように、ソケット2の底面2Aと対向するニップル3の
円形端面3Aの外周部に溝部5が周設され、溝部5とニ
ップル3の端部側面6との間が立ち上がり周壁部4に形
成されている。この構成により、ソケットとニップルと
の螺合部の最終端に発生する応力を緩和するとともに、
電極とニップルとの熱膨張差も吸収して、電極接続部に
おける折損を効果的に減少させることができる。Embodiments of the present invention will be described with reference to the drawings. Note that the same members as those in the related art are denoted by the same reference numerals. In the present invention, as shown in FIGS. 1 and 2, a groove 5 is provided around an outer peripheral portion of a circular end face 3 </ b> A of the nipple 3 facing the bottom surface 2 </ b> A of the socket 2, and the groove 5 and an end side face 6 of the nipple 3 are provided. Is formed on the rising peripheral wall portion 4. With this configuration, while reducing the stress generated at the final end of the threaded portion between the socket and the nipple,
The difference in thermal expansion between the electrode and the nipple can also be absorbed, and breakage at the electrode connection can be effectively reduced.
【0017】立ち上がり周壁部4の端面肉厚tは、円形
端面3Aの直径Dの1〜30%とするのが好ましく、1
〜30%の厚さとすることにより、操業条件にかかわら
ず、電極の横割れおよび縦割れを確実に防止することが
できる。周壁部4の端面肉厚tが円形端面3Aの直径D
の1%未満では、立ち上がり部分が破壊される現象を招
き、30%を越えると、電極の横割れや縦割れを防止す
る効果が低下する。The thickness t of the end face of the rising peripheral wall portion 4 is preferably set to 1 to 30% of the diameter D of the circular end face 3A.
By setting the thickness to 3030%, horizontal cracks and vertical cracks of the electrode can be reliably prevented regardless of operating conditions. The thickness t of the end surface of the peripheral wall portion 4 is the diameter D of the circular end surface 3A.
If it is less than 1%, the rising portion is destroyed, and if it exceeds 30%, the effect of preventing lateral cracks and vertical cracks of the electrode is reduced.
【0018】溝部5の深さは、とくに規定しないが、ニ
ップル3の強度を考慮すると、実用上はニップル3の半
長L/2の半分以下の長さとするのが好ましい。また、
溝部5の底部は丸みを付けるのが好ましい。さらに、溝
部5の幅は5〜50mmとするのが好ましい。図1〜2
において、溝部5は、ニップル3に軸方向と平行に形成
されているが、ニップルとソケットの螺合の終端部の応
力集中を低下させるという目的を達成することができれ
ば、必ずしも平行に形成されなくてもよい。Although the depth of the groove 5 is not particularly limited, in consideration of the strength of the nipple 3, it is practically preferable to set the length to half or less the half length L / 2 of the nipple 3. Also,
The bottom of the groove 5 is preferably rounded. Further, the width of the groove 5 is preferably 5 to 50 mm. Figures 1-2
In the above, the groove 5 is formed in the nipple 3 in parallel with the axial direction, but is not necessarily formed in parallel if the object of reducing the stress concentration at the end of the screwing of the nipple and the socket can be achieved. You may.
【0019】ニップル3の円形端面3Aの中央部7は、
ニップルの端面強度を保持するために機能するととも
に、ニップルの取扱いを容易にする。中央部7には、電
極使用中の応力の緩和度を調整するために、必要に応じ
て孔開け、スリット形成などの加工を行ってもよい。The central portion 7 of the circular end face 3A of the nipple 3
It functions to maintain the strength of the nipple end face and facilitates handling of the nipple. In order to adjust the degree of stress relaxation during use of the electrode, processing such as drilling and slit formation may be performed on the central portion 7 as necessary.
【0020】ソケットの円形端面の周壁部4は、図1〜
2に示すように、連続的に形成することもできるが、図
3に示すように、応力の吸収度、分散度を調整するため
に、周壁部4の1個所または複数個所に切欠き8を設け
ることもできる。複数個所に切欠き8を設ける場合には
放射状に設けるのが好ましい。The peripheral wall 4 of the circular end face of the socket is shown in FIGS.
As shown in FIG. 2, it can be formed continuously, but as shown in FIG. 3, in order to adjust the degree of stress absorption and the degree of dispersion, a notch 8 is formed at one or more places on the peripheral wall portion 4. It can also be provided. When the cutouts 8 are provided at a plurality of locations, they are preferably provided radially.
【0021】[0021]
【実施例】以下、本発明の実施例について説明する。 実施例1 外径762mm(30インチ)の電極ポールの両端に、
深さが310mmのソケットを形成し、図1、図2に示
すように、端面3Aに連続的に溝部5を周設したニップ
ル(端面径292mm)を螺入して電極ポールを接続し
た。Embodiments of the present invention will be described below. Example 1 At both ends of an electrode pole having an outer diameter of 762 mm (30 inches),
A socket having a depth of 310 mm was formed, and as shown in FIGS. 1 and 2, a nipple (end surface diameter 292 mm) having a groove 5 continuously formed around the end surface 3A was screwed in to connect an electrode pole.
【0022】溝部5の幅は20mm、深さは100mm
とし、ニップルの円形端面の最外端縁部には、端面肉厚
(t)30mmの連続的な周壁部を形成した。The width of the groove 5 is 20 mm and the depth is 100 mm
The outer peripheral edge of the circular end face of the nipple was formed with a continuous peripheral wall having an end face thickness (t) of 30 mm.
【0023】150トン電気製鋼炉に、上記のように接
続方式の黒鉛電極を装着し、1か月の連続操業を行った
ところ、電極接続部の折損事故率はいずれも3%以下で
あった。When the graphite electrode of the connection type was attached to the 150-ton electric steelmaking furnace as described above, and the continuous operation was performed for one month, the breakage rate of the electrode connection was 3% or less in all cases. .
【0024】これに対して、外径762mm(30イン
チ)の電極ポールの両端に,深さHが300mmのソケ
ットを形成し、端面に溝部を形成しない通常のニップル
(端面径380mm)を螺入して接続した電極ポールを
使用して、同じ炉中で1か月の連続操業を行った結果、
電極接続部の折損事故率は10%を越えた。On the other hand, a socket having a depth H of 300 mm is formed at both ends of an electrode pole having an outer diameter of 762 mm (30 inches), and a normal nipple (380 mm in end face) having no groove formed in the end face is screwed therein. As a result of one month of continuous operation in the same furnace using the electrode poles connected
The breakage rate of the electrode connection exceeded 10%.
【0025】また、溝部の幅20mm、深さ100m
m、端面肉厚(t)が30mmで、3箇所に放射状に幅
5mmの切欠きを設けた周壁部を形成した電極ポールに
ついても、上記と同様に電気製鋼炉に装着、1か月の連
続操業を行ったが、電極接続部の折損事故率は3%以下
であった。The groove has a width of 20 mm and a depth of 100 m.
m, an electrode pole having an end wall thickness (t) of 30 mm and a peripheral wall portion having a notch with a width of 5 mm radially formed at three places was attached to an electric steelmaking furnace in the same manner as described above, and was continuously mounted for one month. The operation was performed, but the breakage rate of the electrode connection was 3% or less.
【0026】[0026]
【発明の効果】本発明によれば、電気製鋼炉用黒鉛電極
において、電極ポールの両端部に形成したソケットにニ
ップルを螺入して電極ポールを相互に接続して操業する
場合、ソケットとニップルとの螺合部の最終端に発生す
る応力を緩和し、且つ電極とニップルとの熱膨張差も吸
収して、電極接続部における折損事故を防止することを
可能とする電極用ニップルが提供される。According to the present invention, in a graphite electrode for an electric steelmaking furnace, when a nipple is screwed into a socket formed at both ends of an electrode pole and the electrode poles are connected to each other, the socket and the nipple are operated. A nipple for an electrode is provided which alleviates the stress generated at the final end of the screwed portion with the electrode and absorbs the difference in thermal expansion between the electrode and the nipple, thereby preventing a breakage accident at the electrode connection portion. You.
【図1】本発明の電極用ニップルの一実施例を示す縦断
面図である。FIG. 1 is a longitudinal sectional view showing one embodiment of a nipple for an electrode of the present invention.
【図2】図1の電極用ニップルの端面図である。FIG. 2 is an end view of the electrode nipple of FIG. 1;
【図3】本発明の電極用ニップルの他の実施例を示す斜
視図である。FIG. 3 is a perspective view showing another embodiment of the electrode nipple of the present invention.
【図4】従来の黒鉛電極の接続を示す一部断面図であ
る。FIG. 4 is a partial cross-sectional view showing connection of a conventional graphite electrode.
【図5】従来の黒鉛電極の接続部における割れ発生状況
を示す一部断面図である。FIG. 5 is a partial cross-sectional view showing a state of occurrence of a crack in a connection portion of a conventional graphite electrode.
【図6】従来の黒鉛電極の接続部を示す一部断面図であ
る。FIG. 6 is a partial cross-sectional view showing a connection part of a conventional graphite electrode.
【図7】従来の電極用ニップルの一例を示す斜視図であ
る。FIG. 7 is a perspective view showing an example of a conventional electrode nipple.
【図8】従来の黒鉛電極の接続部を示す一部断面図であ
る。FIG. 8 is a partial cross-sectional view showing a connection part of a conventional graphite electrode.
【図9】図8のニップルの端面図である。FIG. 9 is an end view of the nipple of FIG. 8;
1 電極ポール 2 ソケット 2A ソケットの底面 3 ニップル 3A ニップルの端面 4 周壁部 5 溝部 6 端部側面 7 中央部 8 切欠き 9 肉ぬすみ部 10 切込み溝 11 空所 12 切り溝 DESCRIPTION OF SYMBOLS 1 Electrode pole 2 Socket 2A Socket bottom 3 Nipple 3A Nipple end face 4 Peripheral wall 5 Groove 6 End side 7 Central 8 Notch 9 Flushed section 10 Cut groove 11 Void 12 Cut groove
Claims (4)
螺入して電極ポールを相互に接続する電気製鋼炉用黒鉛
電極のニップルにおいて、ソケットに螺入したときソケ
ットの底面と対向するニップルの円形端面に溝部が周設
され、該溝部とニップルの端部側面とによって立ち上が
り周壁部が形成されていることを特徴とする電極用ニッ
プル。1. A nipple for a graphite electrode for an electric steelmaking furnace, which is screwed into a socket formed at an end of an electrode pole and interconnects the electrode pole, wherein the nipple is opposed to the bottom surface of the socket when screwed into the socket. A nipple for an electrode, wherein a groove is formed around a circular end face, and a rising peripheral wall is formed by the groove and a side surface of an end of the nipple.
螺入して電極ポールを相互に接続する電気製鋼炉用黒鉛
電極のニップルにおいて、ソケットに螺入したときソケ
ットの底面と対向するニップルの円形端面に溝部が周設
され、該溝部とニップルの端部側面との間が円形端面の
直径の1〜30%の端面肉厚を有する立ち上がり周壁部
に形成されていることを特徴とする電極用ニップル。2. A nipple of a graphite electrode for an electric steelmaking furnace, which is screwed into a socket formed at an end of an electrode pole and interconnects the electrode pole, wherein the nipple is opposed to a bottom surface of the socket when screwed into the socket. An electrode, wherein a groove is provided around the circular end face, and a portion between the groove and the end side face of the nipple is formed on a rising peripheral wall having an end face wall thickness of 1 to 30% of the diameter of the circular end face. For nipple.
特徴とする請求項1または2記載の電極用ニップル。3. The nipple for an electrode according to claim 1, wherein the peripheral wall portion is formed continuously.
が形成されていることを特徴とする請求項1または2記
載の電極用ニップル。4. The nipple for an electrode according to claim 1, wherein a notch is formed at one or a plurality of positions on the peripheral wall portion.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP15552598A JP3672220B2 (en) | 1998-06-04 | 1998-06-04 | Nipple for electrode |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP15552598A JP3672220B2 (en) | 1998-06-04 | 1998-06-04 | Nipple for electrode |
Publications (2)
Publication Number | Publication Date |
---|---|
JPH11345685A true JPH11345685A (en) | 1999-12-14 |
JP3672220B2 JP3672220B2 (en) | 2005-07-20 |
Family
ID=15607981
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP15552598A Expired - Fee Related JP3672220B2 (en) | 1998-06-04 | 1998-06-04 | Nipple for electrode |
Country Status (1)
Country | Link |
---|---|
JP (1) | JP3672220B2 (en) |
-
1998
- 1998-06-04 JP JP15552598A patent/JP3672220B2/en not_active Expired - Fee Related
Also Published As
Publication number | Publication date |
---|---|
JP3672220B2 (en) | 2005-07-20 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
GB883759A (en) | Improvements in or relating to screw joints between graphite or other carbon electrodes | |
EP1878314B1 (en) | Electrode joint | |
JPH11345685A (en) | Nipple for electrode | |
US4679206A (en) | Electrode joint thread form | |
US4159184A (en) | Friable thread electrode joint | |
JP2781332B2 (en) | Carbon electrode fittings | |
EP1591738B1 (en) | Graphite electrode for steelmaking | |
JPH0922777A (en) | Binding device to avoid looseness of electrode joint | |
JPS59180990A (en) | Electrode for electric arc furnace | |
US3646240A (en) | Electrode joint | |
CN210638502U (en) | Prefabricated brick of refractory lining of furnace | |
JPS591357Y2 (en) | Nipple for carbon electrode | |
JPS58958Y2 (en) | Joints of graphite electrodes for steelmaking | |
JPH10321364A (en) | Graphite electrode for electric furnace | |
JPS6224957Y2 (en) | ||
JP3732432B2 (en) | Graphite electrode connection structure | |
JP3669662B2 (en) | Connection structure of graphite electrode for electric furnace | |
JPS6336639Y2 (en) | ||
CA1103729A (en) | Friable socket thread electrode joint | |
JPH07169566A (en) | Connecting nipple of graphite electrode for dc electric steel making furnace | |
JPH0115114Y2 (en) | ||
TWI712746B (en) | A self-tapping screw | |
CN211423124U (en) | Cylinder head bolt with inner hexagonal head | |
CN209875685U (en) | Torque nut | |
JPS6237347Y2 (en) |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
TRDD | Decision of grant or rejection written | ||
A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20050414 |
|
A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20050415 |
|
R150 | Certificate of patent or registration of utility model |
Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20080428 Year of fee payment: 3 |
|
FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20090428 Year of fee payment: 4 |
|
FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20090428 Year of fee payment: 4 |
|
FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20100428 Year of fee payment: 5 |
|
FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110428 Year of fee payment: 6 |
|
LAPS | Cancellation because of no payment of annual fees |