JPS60197318A - Finishing process in spark machining - Google Patents
Finishing process in spark machiningInfo
- Publication number
- JPS60197318A JPS60197318A JP5333184A JP5333184A JPS60197318A JP S60197318 A JPS60197318 A JP S60197318A JP 5333184 A JP5333184 A JP 5333184A JP 5333184 A JP5333184 A JP 5333184A JP S60197318 A JPS60197318 A JP S60197318A
- Authority
- JP
- Japan
- Prior art keywords
- machining
- electrode
- discharge
- workpiece
- processing
- 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
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23H—WORKING OF METAL BY THE ACTION OF A HIGH CONCENTRATION OF ELECTRIC CURRENT ON A WORKPIECE USING AN ELECTRODE WHICH TAKES THE PLACE OF A TOOL; SUCH WORKING COMBINED WITH OTHER FORMS OF WORKING OF METAL
- B23H7/00—Processes or apparatus applicable to both electrical discharge machining and electrochemical machining
- B23H7/26—Apparatus for moving or positioning electrode relatively to workpiece; Mounting of electrode
- B23H7/28—Moving electrode in a plane normal to the feed direction, e.g. orbiting
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Electrical Discharge Machining, Electrochemical Machining, And Combined Machining (AREA)
Abstract
Description
【発明の詳細な説明】
本発明は、型彫放電加工等により形成された加工部に対
し、より平滑な鏡面仕上等の仕上加工をより速い速度で
放電加工により行なうことを可能被加工体と加工電極と
をケロシン等の所定の加工液中で微小間隔を隔てて対向
させ、前記被加工体と前記加工電極との間に間歇的に電
圧パルスを印加することにより加工を行なう放電加工に
おいては、lパルス当たりの加工量が大であれば加工速
度は速くなる反面、加工面が粗くなるという欠点があり
、1パルス当たりの加工量を小とすれば加工速度は遅く
なるが、加工面が平滑化される。仕上加工において、仕
上加工面を極力平滑化して加工速度を上げるには、原理
的には1パルス当たりの加工量を小としてパルス間隔を
短かくすれば良い訳であるが、放電パルスの微細化およ
びパルス間隔を短かくする(即ち周波数を上げる)には
限界がある。即ち、放電回路には、導電ケーブルや被加
工体と加工電極の対向部、即ち加工間隙の加工面積に応
じる静電容量、および導電ケーブルのインダクタンスが
存在するので、仮に充放電用のコンデンサを設けていな
い場合であっても、被加工体と加工電極間の電圧の立上
がりに時あり、このために、従来の電子スイッチをオン
オフ制御して加工用の電圧パルス列を形成供給する方式
の放電加工においては、一般的には放電パルスの発生周
期を1〜2pS以下にはできなかったのである。このた
め、仕上加工においては、コンデンサ充放電方式を用い
るものが多かったが、加工速度や電極消耗等の点で満足
すべき結果が得られていなかった。また、放電パルスの
発生周期を短かくすると、いわゆるアーク放電を生じゃ
すくなるという問題があった。DETAILED DESCRIPTION OF THE INVENTION The present invention makes it possible to perform finish machining such as a smoother mirror finish on a machined part formed by die-sinking electric discharge machining or the like at a faster speed. In electrical discharge machining, machining is performed by placing a machining electrode facing each other at a small distance in a predetermined machining fluid such as kerosene, and applying voltage pulses intermittently between the workpiece and the machining electrode. If the amount of machining per pulse is large, the machining speed will be faster, but the disadvantage is that the machined surface will be rougher.If the amount of machining per pulse is smaller, the machining speed will be slower, but the machining surface will be Smoothed. In finishing machining, in order to make the finished surface as smooth as possible and increase the machining speed, it is theoretically possible to reduce the amount of machining per pulse and shorten the pulse interval. Also, there is a limit to shortening the pulse interval (that is, increasing the frequency). In other words, in the discharge circuit, there is a capacitance corresponding to the machining area of the conductive cable, the opposing part of the workpiece and the machining electrode, that is, the machining gap, and an inductance of the conductive cable, so it is assumed that a capacitor for charging and discharging is provided. Even when the voltage is not applied, there are times when the voltage between the workpiece and the machining electrode rises, and for this reason, in electrical discharge machining, which controls the on/off of a conventional electronic switch to form and supply a voltage pulse train for machining. In general, it has not been possible to reduce the period of discharge pulse generation to 1 to 2 pS or less. For this reason, in finishing machining, a capacitor charging/discharging method was often used, but satisfactory results were not obtained in terms of machining speed, electrode wear, etc. Furthermore, there is a problem in that shortening the generation period of discharge pulses tends to cause so-called arc discharge.
本発明は、上述の点に鑑み、1放電パルス当たりの゛加
工量を小として鏡面仕上面を得ると共に、仕上加工が高
速に行なえる放電加工における仕上加工方法を提供する
ことを目的としてなされたものである。In view of the above-mentioned points, the present invention has been made for the purpose of providing a finishing machining method in electric discharge machining that can obtain a mirror-finished surface by reducing the amount of machining per one discharge pulse and can perform finishing machining at high speed. It is something.
この目的を達成するため、本発明においては、加工電極
および被加工体に形成されている加工部の面積よりも小
さい対向面積の加工間隙が形成されるように、加工電極
を所定の加工液中で微小間隔を隔てて前記加工部に対向
させることにより、静電容量の小さい放電回路を形成し
、前記被加工体と前記加工電極との間に直流または電圧
パルスを印加し、かつ前記加工間隙を形成する対向面積
が所定値以下であるように前記被加工体と前記加工電極
とを相対的に移動させながら加工を“行rうことを特徴
とする。In order to achieve this objective, in the present invention, the machining electrode is immersed in a predetermined machining liquid so that a machining gap with an opposing area smaller than the area of the machining part formed on the machining electrode and the workpiece is formed. A discharge circuit with a small capacitance is formed by facing the machining part with a minute interval between the two, and a direct current or voltage pulse is applied between the workpiece and the machining electrode, and the machining gap is The method is characterized in that the processing is carried out while relatively moving the workpiece and the processing electrode so that the opposing area forming the area is less than or equal to a predetermined value.
以下本発明の詳細を図面に示す実施例により説明する。The details of the present invention will be explained below with reference to embodiments shown in the drawings.
第1図に示すように、本実施例においては、商用交流電
源または商用交流を一旦整流して直流にした後、スイッ
チ素子によるスイッチングにより所定の高い周波数の交
流とした交流電源1を設け、トランス2により、ピーク
電圧が80v〜1500V程度になるように変圧し、整
流器3で整流して直流とした後、限流抵抗4を介して放
電回路5.6の加工電極7と被加工体8の対向間隙に印
加する。また、加工電極7と被加工体8が、加工中の時
々刻々に形成する加工間隙の対向面積が常に所定値以下
、例えば約5’cm2前後以下、好ましくは2〜3 c
ra2以下の約1ca12前後の小さな値を保つように
、対向面積の形成を制御することにより、放電回路5,
6間の浮遊容量Cが小さくなるようにする。具体的には
、加工電極の対向面積は一般的には約5 cm2前後以
下、好ましくは2〜3 c+a2以下の約IC112前
後の小さな値とし、間隙容量は50〜100FF前後ま
たはそれ以下とすることが好ましい。この場合、放電回
路5.6のインダクタンスも可及的に小さくなるように
することが好ましいのは勿論である。As shown in FIG. 1, in this embodiment, an AC power source 1 is provided, in which a commercial AC power source or commercial AC is once rectified into DC, and then converted into AC at a predetermined high frequency by switching with a switch element. 2, the voltage is transformed so that the peak voltage is about 80 V to 1500 V, and after rectifying it with a rectifier 3 to make direct current, it is connected to the machining electrode 7 of the discharge circuit 5.6 and the workpiece 8 via the current limiting resistor 4. applied to the opposing gap. Further, the facing area of the machining gap formed momentarily between the machining electrode 7 and the workpiece 8 during machining is always less than a predetermined value, for example, about 5'cm2 or less, preferably 2 to 3 cm2.
The discharge circuit 5,
The stray capacitance C between 6 and 6 is made small. Specifically, the opposing area of the processing electrode should generally be about 5 cm2 or less, preferably a small value of about 2 to 3 C+A2 or less, about IC112, and the gap capacity should be about 50 to 100 FF or less. is preferred. In this case, it is of course preferable that the inductance of the discharge circuit 5.6 is also made as small as possible.
さらに、必要に応じ、加工電極7につながる回路5と被
加工体8につながる回路6とを所定の周期で短絡するこ
とができるようにスイッチ素子lOを設け、予め設定し
た周波数の発振器の出力を一定の割合で分周するか、加
工間隙の加工状態判別器9の出力により分周割合を変え
、この分周信号を整流およびレベル調節する制御回路1
1より前記スイッチ素子10に制御信号を加えて該スイ
ッチ素子10をオンオフする。該スイッチ素子10に加
えるパルスの周期は、第2図においてのτonとτ岨で
示す時間の合計TIであり、この周期期の数倍以上とな
るように選定する。例えば、加工間隙と放電回路5.6
のリード線等による浮遊容量の充放電による高周波放電
の周期に応じて。Furthermore, if necessary, a switch element IO is provided so that the circuit 5 connected to the processing electrode 7 and the circuit 6 connected to the workpiece 8 can be short-circuited at a predetermined period, and the output of the oscillator at a preset frequency is controlled. A control circuit 1 that divides the frequency at a constant rate or changes the frequency division rate according to the output of the machining state discriminator 9 of the machining gap, and rectifies and adjusts the level of this frequency-divided signal.
1, a control signal is applied to the switch element 10 to turn the switch element 10 on and off. The period of the pulse applied to the switch element 10 is the sum TI of the times τon and τin in FIG. 2, and is selected so as to be several times or more of this period. For example, machining gap and discharge circuit 5.6
Depending on the period of high-frequency discharge due to charging and discharging of stray capacitance through lead wires, etc.
0.1〜500ILS加工してo、1ILs N10m
S中断するようにする。0.1~500ILS processing o, 1ILs N10m
S Interrupt.
前記のように、浮遊容量Cが(好ましくはさらにインダ
クタンスも)可及的に小さくなるようにすることにより
、第3図のVに示すように、放電回路に印加される直流
電圧による放電回路の浮遊容量の充電電圧特性は、電圧
の変化がVlで示すように遅れるのに比較し、v2で示
すように立上がりが急峻となり、このために高周波の充
放電による加工が可能となり、加工電極7と被加工体8
の間で微小の所定エネルギの放電電流Iを流し加工を進
行させることができる。As mentioned above, by making the stray capacitance C (preferably also the inductance) as small as possible, the discharge circuit due to the DC voltage applied to the discharge circuit is reduced as shown by V in FIG. The charging voltage characteristic of the stray capacitance is that the voltage change is delayed as shown by Vl, but the rise is steeper as shown by v2. This makes processing by high frequency charging and discharging possible, and the machining electrode 7 and Workpiece 8
Machining can be progressed by flowing a small discharge current I of a predetermined energy between the two.
従って、従来、前述のように加工間隙および放電回路の
浮遊容量の充放電による放電加工では、加工間隙の加工
面積は制限されておらず、従って加工の進行に伴なって
増大等変化はするが、大きいために浮遊六目の値本±ま
(,1話雪当斧番1の放電エネルギが大きく、鏡面仕上
げ加工が難しいばかりでなく、仕上げ加工の速度も高周
波放電とならないために遅く、また、各放電の放電電流
ピークはあまり高くなくて各放電間の休止時間が少ない
かほとんど無いため、高周波アーク放電に移行していた
ものが、本発明によれば、浮遊容量、即ち放電エネルギ
の小さい割りには放電電流ピークが大きくてアーク放電
に移行することなく加工することができ、1パルス当た
りの加工量が少なく、かつ高周波放電で各放電間の休止
時間が短かいかほとんど無い状態で加工が行なえるから
、仕上加工面として鏡面を得ることが可能となり、加工
速度も向上する。Therefore, conventionally, in electrical discharge machining by charging and discharging the stray capacitance of the machining gap and the discharge circuit as described above, the machining area of the machining gap is not limited, and therefore it increases or changes as the machining progresses. , Due to its large size, the value of the floating Rokume ± ma (, Episode 1 The discharge energy of Yukito Ax No. 1 is large, and not only is it difficult to process a mirror finish, but the speed of finishing is slow because it does not become a high-frequency discharge, and , the discharge current peak of each discharge is not very high and there is little or no pause time between each discharge, so what used to be a high-frequency arc discharge is now replaced by a high-frequency arc discharge, which has a small stray capacitance, that is, a small discharge energy. The discharge current peak is comparatively large, so machining can be performed without transitioning to arc discharge, the amount of machining per pulse is small, and the pause time between each discharge is short or almost nonexistent due to high frequency discharge. Since this can be done, it becomes possible to obtain a mirror surface as a finished surface, and the processing speed is also improved.
また、本、実施例のように、周期的に高周波放電を中断
すれば、中断中にアークが発生した部分が冷却されかつ
イオンが消滅するので、持続的高周波アーク放電を確実
に防止して高周波交流またはその整流パルスによる高周
波放電加工をすることができるようになる。Furthermore, if the high-frequency discharge is periodically interrupted as in this embodiment, the part where the arc occurred during the interruption will be cooled and the ions will disappear, so that continuous high-frequency arc discharge can be reliably prevented and the high-frequency It becomes possible to perform high-frequency electrical discharge machining using alternating current or its rectified pulses.
次に、本発明において、加工間隙、即ち加工電極7と被
加工体8間の対向面積を所定の小さい値に制限した状態
で加工を行なう具体例を説明する。第4図は、被加工体
8に円形穴状の被加工部8aが形成されている場合の本
発明による仕上加工の例であり、この例における装置は
、テーブル13またはアーム14のいずれか一方がX軸
、Y軸モータにより移動可能に構成されるか、あるいは
テーブル13またはアーム14のいずれか一方がX!1
h−y−タ、他方がY軸モータにより駆動される被加工
体8のX、Y平面上の位置設定機構を有する。アーム1
4の先端には、ラック15を有するロッド16が、アー
ム14上に取付けたZ軸モータ17の出力軸ピニオン1
8をラック15に噛合させることにより、上下に移動さ
せられるように取付けられ、該ロッド16の下端にはモ
ータ19によりアーム20が回転自在に取付けられ、該
アーム20に沿って摺動自在にブロック21が嵌合され
、該ブロック21のねじ穴に、アーム20の一端に取付
けたモータ22の出力軸に結合したねじロッド23を螺
合し、該ブロック21に住加工電極7を装着するホルダ
ー24を有する。加工電極7は、図示にように、加工部
8aの面積よりもはるかに小さい表面積の小さな円柱状
の形状のものであるが、形状は円柱状以外に種々の形状
が採用できる。Next, a specific example will be described in which, in the present invention, machining is performed with the machining gap, that is, the opposing area between the machining electrode 7 and the workpiece 8 being limited to a predetermined small value. FIG. 4 shows an example of finishing processing according to the present invention when a circular hole-shaped part 8a is formed in the workpiece 8. is configured to be movable by X-axis and Y-axis motors, or either table 13 or arm 14 is configured to be movable by X! 1
The machine has a mechanism for positioning the workpiece 8 on the X and Y planes, the other being driven by a Y-axis motor. Arm 1
A rod 16 having a rack 15 is connected to the output shaft pinion 1 of a Z-axis motor 17 mounted on the arm 14.
8 is engaged with a rack 15 so that it can be moved up and down. An arm 20 is rotatably attached to the lower end of the rod 16 by a motor 19, and a block is slidably moved along the arm 20. 21 is fitted, and a threaded rod 23 coupled to the output shaft of a motor 22 attached to one end of the arm 20 is screwed into the screw hole of the block 21, and the housing processing electrode 7 is mounted on the block 21. has. As shown in the figure, the processing electrode 7 has a small cylindrical shape with a surface area much smaller than the area of the processing portion 8a, but various shapes other than the cylindrical shape can be adopted.
この装置を用いて仕上加工を行なう場合には、被加工体
8のX、Y平面上の位置設定機構をNC装置(いずれも
図示せず)等により作動させることにより、被加工部8
aの中心を前記アーム20の回転中心に一致させる。ま
た、モータ22を作動させて加工電極7を加工部8aの
内壁との間に微小間隔が形成されるようにし、かつモー
タ17を作動させて加工電極7をその底面が加工部8a
の底面に微小間隔を介して対向するように下降させた後
、加工部8aを加工液に浸漬した状態で加工電極7ある
いはその近傍から加工液を噴出させながら(この加工液
の噴出機構については図示していない)、モータ19を
作動させて加工電極7をアーム20の回転中心を中心と
して回転させつ6出力を接続し電圧を印加する。このよ
うにすると加工間隙の対向面積は加工電極7の径にもよ
るが、数cm2前後またはそれ以下で、加工部8aを順
次にスキャンニングして加工することができ、加工電極
7を1回転あるいは数回転させた後は、加工電極7の回
転半径を小さくし、かつ回転速度を大きくして同様の加
工動作を繰返えす。この反対に、回転半径を漸次増大さ
せながら加工してもよく、さらに螺旋状に動かしてもよ
い。When performing finishing processing using this device, the position setting mechanism of the workpiece 8 on the X and Y planes is operated by an NC device (none of which is shown), etc.
The center of a is made to coincide with the rotation center of the arm 20. Further, the motor 22 is operated so that a minute gap is formed between the machining electrode 7 and the inner wall of the machining portion 8a, and the motor 17 is activated so that the machining electrode 7 is moved so that the bottom surface thereof is the machining portion 8a.
is lowered so as to face the bottom surface of the electrode 7 with a small distance therebetween, and while the machining fluid is jetted from the machining electrode 7 or its vicinity while the machining part 8a is immersed in the machining fluid (the mechanism for ejecting this machining fluid is (not shown), the motor 19 is operated to rotate the processing electrode 7 around the rotation center of the arm 20, and six outputs are connected to apply a voltage. In this way, the opposing area of the machining gap depends on the diameter of the machining electrode 7, but it is around several cm2 or less, and the machining part 8a can be sequentially scanned and machined, and the machining electrode 7 can be rotated once. Alternatively, after several rotations, the radius of rotation of the machining electrode 7 is made smaller, the rotational speed is increased, and the same machining operation is repeated. On the contrary, the machining may be performed while gradually increasing the rotation radius, or the material may be moved in a spiral manner.
第5図は球状面8bを被加工体8Aに形成する場合の一
例であり、加工電極7Aは加工面である球状面8bの面
積の数分の1以下即ち数0112前後またはそれ以下の
対向面積の球状面を有するものを用い、モータ25によ
り回転される回転テーブル26上に載置した加工槽27
内の加工液28中に、該被加工体8Aを、その中心がモ
ータ25による回転中心と一致するように位置決めして
浸漬し、一方、前記Z軸方向の位置が調節できるロッド
16には、弧状のガイド穴29aを有する電極プル26
のX、Y軸方向位置設定機構により、ガイド穴29aが
前記球状面8bと同心状をなすように位置決めし、前記
加工電極7Aを取付けたアーム30と一体の弧状のガイ
ド体30aを前記ガイド穴29aに摺動可能に嵌合し、
前記ロッド16に取付けたモータ31の出力ねじロッド
32と噛合するねじロッド33と前記アーム30とをリ
ンク34およびピン35.36により連結し、モータ2
5を作動させて被加工体8Aを回転させながら、モータ
31を作動させることにより、加工電極7Aを被加工体
8Aの球状面8bに沿って矢印37の方向、またはその
反対方向に連続的または段階的に移動させ、前記のよう
に被加工体8Aと加工電極7Aとの間に放電回路5,6
の出力を接続して電圧を印加し、かつ図示しない機構に
より加工電極7A等から加工液を噴出しながら加工を行
なうようにしたものである。なお、テーブル26を回転
させるのではなく、ロッド16を回転させるようにして
もよい。FIG. 5 is an example of forming a spherical surface 8b on a workpiece 8A, and the processing electrode 7A has an opposing area of less than a fraction of the area of the spherical surface 8b, which is the processing surface, that is, around 0112 or less. A processing tank 27 is placed on a rotary table 26 which is rotated by a motor 25.
The workpiece 8A is positioned and immersed in the machining fluid 28 in the center so that its center coincides with the center of rotation by the motor 25, while the rod 16 whose position in the Z-axis direction can be adjusted is Electrode pull 26 having an arcuate guide hole 29a
The guide hole 29a is positioned concentrically with the spherical surface 8b by the X and Y axis direction positioning mechanism, and the arc-shaped guide body 30a integrated with the arm 30 to which the processing electrode 7A is attached is aligned with the guide hole 29a. 29a to be slidably fitted,
The threaded rod 33 that meshes with the output threaded rod 32 of the motor 31 attached to the rod 16 and the arm 30 are connected by a link 34 and pins 35 and 36, and the motor 2
By operating the motor 31 while rotating the workpiece 8A by operating the workpiece 8A, the machining electrode 7A is continuously or The electric discharge circuits 5 and 6 are moved between the workpiece 8A and the machining electrode 7A as described above.
A voltage is applied by connecting the output of , and machining is performed while spouting machining liquid from the machining electrode 7A and the like by a mechanism not shown. Note that instead of rotating the table 26, the rod 16 may be rotated.
第6図は球面部8bの仕−ヒ加工を行なう別の例であり
、球面部8bの半径よりもやや大きい椀状の加工電極7
Bを球面部8bに被せるようにセットし、球面部8bの
側面部aの仕上加工を行なう場合には加工電極7Bを実
線で示すように図面上人に変位させ、頂部すないしはそ
の近傍の加工を行なう場合には2点鎖線7B’に示すよ
うに加工電極を下げるという風に、加工電極7Bの高さ
、位置あるいは傾きを変化させることにより、あるいは
加工電極7Bと被加工体8Aとを相対的に回転させるこ
とにより、実質的な対向面積を数C112前後またはそ
れ以下の小さい値に保つ狭くして加工を行なうようにし
たものである。FIG. 6 shows another example of machining the spherical part 8b, in which a bowl-shaped machining electrode 7 whose radius is slightly larger than the radius of the spherical part 8b is shown.
B is set so as to cover the spherical part 8b, and when finishing the side surface part a of the spherical part 8b, the processing electrode 7B is displaced as shown by the solid line in the drawing, and the top part or its vicinity is processed. When performing this, the height, position, or inclination of the machining electrode 7B may be changed by lowering the machining electrode as shown by the two-dot chain line 7B', or the machining electrode 7B and the workpiece 8A may be moved relative to each other. By rotationally rotating the material, the actual opposing area can be narrowed to a small value of around a few C112 or less.
第7図は被加工体8Bの球状凹面8bの仕上加工を行な
う例であり、前記モータ425を作動させて被加工体8
Aを回転させながら、前記ロッド16に取付けたモータ
40を作動させることにより、その出力ねじロッド41
と噛合するねじロッド42と、リンク43とを介して、
ロッド16にビン38により揺動可能に取付けられたア
ーム39を矢印44方向(またはその反対方向)に連続
的または段階的に回動させ、該アーム39に取付けた加
工電極7C(この加工電極は、前記球状凹面8Cに沿う
弧状面を有して該弧状面が球状凹面8cに対向するよう
に位置決めされる)を球状凹面8cに沿っ移動させるこ
とにより、加工を行なうようにしたものである。なお、
この場合もテーブル26を回転させるのではなく、ロッ
ド16を回転させるよう−にしてもよい。また、第6図
の場合とは逆に、球状凹面8cよりやや小径の外径を有
する球状加工電極を用い、第6図で説明したように該球
状加工電極を球状凹面8c内で変位させることにより、
球状加工電極が球状凹面8cに近接した位置で放電が生
じるようにしてもよい。FIG. 7 shows an example of finishing the spherical concave surface 8b of the workpiece 8B, in which the motor 425 is operated and the workpiece 8B is finished.
By operating the motor 40 attached to the rod 16 while rotating the rod 16, the output threaded rod 41
Through the threaded rod 42 that meshes with the link 43,
An arm 39 that is swingably attached to the rod 16 by a bottle 38 is rotated continuously or stepwise in the direction of arrow 44 (or the opposite direction), and the processing electrode 7C attached to the arm 39 (this processing electrode , which has an arcuate surface along the spherical concave surface 8C, and is positioned so that the arcuate surface faces the spherical concave surface 8c) is moved along the spherical concave surface 8c to carry out processing. In addition,
In this case as well, instead of rotating the table 26, the rod 16 may be rotated. Moreover, contrary to the case of FIG. 6, a spherical machining electrode having an outer diameter slightly smaller than the spherical concave surface 8c is used, and the spherical machining electrode is displaced within the spherical concave surface 8c as explained in FIG. According to
The electric discharge may be generated at a position where the spherical processing electrode is close to the spherical concave surface 8c.
第8図は被加工体8cに加工された溝8dの仕上加工を
行なう場合の加工例であり、X軸またはYiモータ45
により動かされるテーブル46上にテーブル46の移動
方向と溝8dの方向が一致するように被加工体8cを位
置決めし、溝8dの底面角度、例えば約60度に対して
先端角度が例えば約50度と小さく、かっ溝8dの長さ
より短かい加工電極7Dを、前記ロッド16に例えば図
示のように上下動用シリンダ47により取付け、該シリ
ンダ47を伸長させて溝8dに加工電極7Dを微小間隔
、を介して対向させた状態でシリンダ47傾動装置48
により、シリンダ47を電極7Dの先端近くを傾動支点
とするように、シリンダ47を溝8dの軸方向と直角方
向に溝8dの底面角度と電極7D先端角度の差に応じた
角度の往復傾動を毎秒数回前後またはそれ以下でゆっく
り行なわせつつ、X軸またはY軸モータ45によりテー
ブル46を連続的または図示のa、b、c。FIG. 8 shows an example of finishing a groove 8d machined in a workpiece 8c, using the X-axis or Yi motor 45.
The workpiece 8c is positioned on the table 46, which is moved by the table 46, so that the moving direction of the table 46 matches the direction of the groove 8d, and the tip angle is approximately 50 degrees relative to the bottom angle of the groove 8d, for example approximately 60 degrees. The machining electrodes 7D, which are small and shorter than the length of the beveled grooves 8d, are attached to the rod 16 using, for example, a vertical movement cylinder 47 as shown in the figure, and by extending the cylinder 47, the machining electrodes 7D are placed in the grooves 8d at minute intervals. The cylinders 47 and the tilting device 48 are placed opposite each other through the
As a result, the cylinder 47 is tilted back and forth at an angle corresponding to the difference between the bottom angle of the groove 8d and the tip angle of the electrode 7D in a direction perpendicular to the axial direction of the groove 8d so that the cylinder 47 is tilted near the tip of the electrode 7D. The X-axis or Y-axis motor 45 moves the table 46 continuously or through the steps a, b, and c shown in the figure while slowly moving back and forth several times per second or less.
dの範囲毎に間歇的に移動させて加工を行なうようにし
たものである。The processing is performed by moving intermittently within each range of d.
次に加工の実例について説明すると、第8図の例におい
て、加工電極7に銅電極を用い、加工液として従来から
通常用いられている白灯油を用い、被加工体8が355
C材である場合において、加工溝8dの面積8c112
に対し加工電極7の対向面積が0.4cm2で、加工間
隙の静電容量を20PFとし、加工電極7を3 cm/
setの速度で移動させ、電圧が300vで短絡電流
が約0.5Aの直流を用い、第2図のオン時間でonを
tpsecとし、オフ時間τ姐を2g、SeCとした場
合には、加工速度は2 、7 mg/min、加工面粗
さは0.28pLmR,、加工電流は最大0.2A、
ピーク電流は20Aとなった。一方、加工溝8dに合致
する形状の加工電極を用いて加工を行なった場合には、
加工速度は3 mg/ mln、加工面粗さは1.IJ
j−mRwとなり、加工電流は0.2A、ピーク電流は
35Aとなった。Next, an example of machining will be described. In the example shown in FIG.
In the case of C material, the area of the processed groove 8d is 8c112
On the other hand, the facing area of the machining electrode 7 is 0.4 cm2, the capacitance of the machining gap is 20PF, and the machining electrode 7 is 3 cm/
When moving at the set speed, using direct current with a voltage of 300 V and a short circuit current of about 0.5 A, on time of tpsec in Figure 2, and off time τ of 2 g, SeC, processing Speed is 2.7 mg/min, machined surface roughness is 0.28 pLmR, machining current is maximum 0.2 A,
The peak current was 20A. On the other hand, when machining is performed using a machining electrode shaped to match the machining groove 8d,
The processing speed was 3 mg/mln, and the machined surface roughness was 1. I.J.
j-mRw, the processing current was 0.2A, and the peak current was 35A.
なお、本発明を実施する場合、加工電極7と被加工体8
との間の放電を、スイッチ10のオン、オフにより放電
周期の数倍以上の周期で断続させれば、前記高周波交流
またはパルスの数倍以上の周期で作用させれば、放電柱
の集中が防止され、さらに高速度の仕上加工が行なえる
。また、加工中に電極の消耗度合によって加工電極の位
置座標を補正するようにすれば、より高精度の仕上加工
が行なえるようになる。また、本発明は、前記のような
単純な形状の加工部のみでなく、複雑な形状の加工部の
仕上加工を行なう場合にも適用でき、その場合には、加
工電極をその形状に合わせて移動や傾動させたり、形状
の異なる複数種類の電極を用いて加工を行なうことにな
る。In addition, when carrying out the present invention, the processing electrode 7 and the workpiece 8
If the discharge between the This allows high-speed finishing to be performed. Moreover, if the positional coordinates of the processing electrode are corrected during processing depending on the degree of wear of the electrode, it becomes possible to perform finishing processing with higher precision. Furthermore, the present invention can be applied not only to finishing parts having a simple shape as described above, but also to finishing parts having a complex shape. Machining is performed by moving or tilting the electrode, or by using multiple types of electrodes with different shapes.
以上述べたように、本発明によれば、加工電極の被加工
体に対する対向面積を保持させて加工するようにしたこ
とにより浮遊容量の小さい放電回路を形成したので、1
放電当たりの放電エネルギは小さく、また、放電エネル
ギおよび放電パルスの幅の小さい割りには放電電流は振
幅を大きくした放電をさせることができ、放電柱が形成
されて放電を進行させることができ、持続的アークの発
生を防止し、仕上面として鏡面を高速の加工速度で得る
ことができる。また本発明によれば、従来不可能であっ
た加工部の広い場合における鏡面加工を行なうことが可
能となる。As described above, according to the present invention, a discharge circuit with small stray capacitance is formed by maintaining the area of the machining electrode facing the workpiece.
The discharge energy per discharge is small, and considering the discharge energy and discharge pulse width are small, the discharge current can be discharged with a large amplitude, and a discharge column can be formed to advance the discharge. It is possible to prevent the generation of persistent arcs and obtain a mirror-like finished surface at a high processing speed. Further, according to the present invention, it becomes possible to perform mirror finishing in a case where the processing area is wide, which was previously impossible.
第1図は本発明の方法を実施する放電加工装置の一例を
示す回路図、第2図は第1図の動作を説明する波形に、
第3図は本発明の放電電圧と放電電流の関係図、第4図
ないし第8図は本発明の方法を実施する放電加工装置の
各側を示す図である。
1・・・交流電源、7,7A〜7D・・・加工電極、8
.8A〜8C・・・被加工体、8a〜8d・・・被加工
部、10・・・スイッチ素子、11・・・制御回路特許
出願人 株式会社井上ジャパックス研究所代理人 弁理
士 若田勝−
第1図
第5図FIG. 1 is a circuit diagram showing an example of an electrical discharge machining apparatus that implements the method of the present invention, and FIG. 2 shows waveforms explaining the operation of FIG.
FIG. 3 is a diagram showing the relationship between discharge voltage and discharge current according to the present invention, and FIGS. 4 to 8 are diagrams showing each side of the electric discharge machining apparatus for carrying out the method of the present invention. 1...AC power supply, 7,7A-7D...processing electrode, 8
.. 8A to 8C...Workpiece, 8a to 8d...Workpiece part, 10...Switch element, 11...Control circuit Patent applicant Inoue Japax Institute Representative Patent attorney Masaru Wakata Figure 1 Figure 5
Claims (1)
面積よりも小さい対向面積の加工間隙が形成されるよう
に、加工電極を所定の加工液中で微小間隔を隔てて前記
加工部に対向させることにより、静電容量の小さい放電
回路を形成し、前記被加工体と前記加工電極との間に直
流または電圧パルスを印加し、かつ前記加工間隙を形成
する対向面積が所定値以下であるように前記被加工体と
前記加工電極とを相対的に移動させながら加工を行なう
ことを特徴とする放電加工における仕上加工方法。The machining electrode is placed in a predetermined machining liquid so as to face the machining part at a small distance so that a machining gap with a facing area smaller than the area of the machining part already formed on the machining electrode and the workpiece is formed. By doing so, a discharge circuit with a small capacitance is formed, a direct current or a voltage pulse is applied between the workpiece and the processing electrode, and the opposing area forming the processing gap is less than or equal to a predetermined value. A finishing machining method in electric discharge machining, characterized in that machining is performed while relatively moving the workpiece and the machining electrode.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP5333184A JPS60197318A (en) | 1984-03-19 | 1984-03-19 | Finishing process in spark machining |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP5333184A JPS60197318A (en) | 1984-03-19 | 1984-03-19 | Finishing process in spark machining |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS60197318A true JPS60197318A (en) | 1985-10-05 |
JPH0521688B2 JPH0521688B2 (en) | 1993-03-25 |
Family
ID=12939748
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP5333184A Granted JPS60197318A (en) | 1984-03-19 | 1984-03-19 | Finishing process in spark machining |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS60197318A (en) |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5721228A (en) * | 1980-07-09 | 1982-02-03 | Sodeitsuku:Kk | Electrical discharge machining method |
JPS57132927A (en) * | 1981-02-03 | 1982-08-17 | Inoue Japax Res Inc | Spark machining device |
-
1984
- 1984-03-19 JP JP5333184A patent/JPS60197318A/en active Granted
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5721228A (en) * | 1980-07-09 | 1982-02-03 | Sodeitsuku:Kk | Electrical discharge machining method |
JPS57132927A (en) * | 1981-02-03 | 1982-08-17 | Inoue Japax Res Inc | Spark machining device |
Also Published As
Publication number | Publication date |
---|---|
JPH0521688B2 (en) | 1993-03-25 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US5651901A (en) | Method and apparatus for surface treatment by electrical discharge machining | |
US4081652A (en) | Electrical discharge machining by means of a wire electrode | |
US6717094B2 (en) | Electrical discharge machine and methods of establishing zero set conditions for operation thereof | |
US2818490A (en) | Means for use in the working of metals by electro-erosion | |
US4992639A (en) | Combined EDM and ultrasonic drilling | |
US5804789A (en) | Surface treating method and apparatus by electric discharge machining | |
US4013526A (en) | Electrochemical grinding with a conductivity-controlled wheel electrode | |
US4430544A (en) | EDM Machine tool with compounded electrode-reciprocation and servo-feed drivers | |
US4487671A (en) | Methods and apparatus for the electrical machining of a workpiece | |
US4471199A (en) | EDM Of a roll using segmented electrode short-circuited in the rough machine step | |
US3969601A (en) | Electronic spark treating and eroding metals | |
US20030024122A1 (en) | Method and apparatus for producing hydrodynamic bearing parts by electrochemical machining | |
JPS60197318A (en) | Finishing process in spark machining | |
JP3289575B2 (en) | Electric discharge machine and method | |
US4230927A (en) | Apparatus for electrical discharge machining of cylindrical work | |
JPH0346245B2 (en) | ||
US4394558A (en) | EDM Method of machining workpieces with a controlled crater configuration | |
JP2730307B2 (en) | Electric discharge machine | |
KR940002875B1 (en) | Electrolytic finishing method | |
SU1301594A1 (en) | Method of extremum control of electro-erosion process | |
JPH0116605B2 (en) | ||
WO1990002625A1 (en) | Centering method in an electrolytic finishing apparatus | |
JPH034335B2 (en) | ||
JPH0413084B2 (en) | ||
JPH0520209B2 (en) |