JPH0716827B2 - Power supply for wire cut electrical discharge machining - Google Patents
Power supply for wire cut electrical discharge machiningInfo
- Publication number
- JPH0716827B2 JPH0716827B2 JP60032734A JP3273485A JPH0716827B2 JP H0716827 B2 JPH0716827 B2 JP H0716827B2 JP 60032734 A JP60032734 A JP 60032734A JP 3273485 A JP3273485 A JP 3273485A JP H0716827 B2 JPH0716827 B2 JP H0716827B2
- Authority
- JP
- Japan
- Prior art keywords
- voltage pulse
- machining
- voltage
- discharge
- application
- 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.)
- Expired - Fee Related
Links
- 238000009763 wire-cut EDM Methods 0.000 title claims description 4
- 238000003754 machining Methods 0.000 claims description 118
- 238000001514 detection method Methods 0.000 claims description 16
- 230000002441 reversible effect Effects 0.000 claims description 6
- 229910045601 alloy Inorganic materials 0.000 description 15
- 239000000956 alloy Substances 0.000 description 15
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 15
- 229910052751 metal Inorganic materials 0.000 description 11
- 239000002184 metal Substances 0.000 description 11
- 238000010586 diagram Methods 0.000 description 9
- 238000009760 electrical discharge machining Methods 0.000 description 8
- 239000003990 capacitor Substances 0.000 description 7
- 238000007599 discharging Methods 0.000 description 6
- 238000005868 electrolysis reaction Methods 0.000 description 6
- 239000012530 fluid Substances 0.000 description 6
- 239000007788 liquid Substances 0.000 description 5
- 150000002739 metals Chemical class 0.000 description 5
- 238000010828 elution Methods 0.000 description 4
- 229910009043 WC-Co Inorganic materials 0.000 description 3
- 239000004480 active ingredient Substances 0.000 description 3
- 230000007423 decrease Effects 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 230000000630 rising effect Effects 0.000 description 3
- 239000011230 binding agent Substances 0.000 description 2
- 239000000470 constituent Substances 0.000 description 2
- 229910052802 copper Inorganic materials 0.000 description 2
- 239000010949 copper Substances 0.000 description 2
- 238000004090 dissolution Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000010304 firing Methods 0.000 description 2
- 150000001247 metal acetylides Chemical class 0.000 description 2
- 229910001369 Brass Inorganic materials 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 238000009825 accumulation Methods 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- 239000010951 brass Substances 0.000 description 1
- 229910052793 cadmium Inorganic materials 0.000 description 1
- 238000005266 casting Methods 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 239000011651 chromium Substances 0.000 description 1
- 229910017052 cobalt Inorganic materials 0.000 description 1
- 239000010941 cobalt Substances 0.000 description 1
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 1
- 230000002950 deficient Effects 0.000 description 1
- 230000003111 delayed effect Effects 0.000 description 1
- 238000010891 electric arc Methods 0.000 description 1
- 238000004146 energy storage Methods 0.000 description 1
- -1 for example Substances 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 1
- 229910052745 lead Inorganic materials 0.000 description 1
- 229910052748 manganese Inorganic materials 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- PXHVJJICTQNCMI-UHFFFAOYSA-N nickel Substances [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 1
- 150000004767 nitrides Chemical class 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
- 229910052718 tin Inorganic materials 0.000 description 1
- 229910052725 zinc Inorganic materials 0.000 description 1
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
- B23H7/02—Wire-cutting
- B23H7/04—Apparatus for supplying current to working gap; Electric circuits specially adapted therefor
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)
Description
【発明の詳細な説明】 （産業上の利用分野） 本発明は、ワイヤカット放電加工用電源装置、特に加工
用電極と被加工物間の加工間隙に間歇的な電圧パルスを
印加することによりパルス放電を生ぜしめる電源装置に
関するもので、特にいわゆる水または水を主成分とする
液を加工液とする放電加工の際に使用して有用な、ある
いはさらに電解により比較的易溶解性の金属、合金を少
なくとも一部以上有効成分として含有する被加工物を加
工する際に適用して有用な電源装置に関するものであ
る。Description: TECHNICAL FIELD The present invention relates to a power supply device for wire-cut electric discharge machining, and in particular, by applying an intermittent voltage pulse to a machining gap between a machining electrode and a workpiece. Metals and alloys that are useful when used in electrical discharge machining using so-called water or a liquid containing water as a main component, or are relatively easily soluble by electrolysis The present invention relates to a power supply device that is useful when applied to a work piece containing at least a part of the above as an active ingredient.
（従来の技術） ワイヤカット放電加工においては、加工液として、通
常、上記水または水を主成分とする水系の加工液が使用
されるが、この場合、一部電解が生じる。この場合、電
解により比較的易溶解性の金属、合金を少なくとも一部
以上有効成分として含有する被加工物としては、例えば
WC−Co合金の如き金属炭化物、金属窒化物、金属硼化物
等の一般的に高硬度、高融点の粒子をFe、Ni、Cr、Cu、
Co、Zn、Al、Cd、Mn、Sn、Pb等の金属、合金を結合材と
して焼成等により固めたいわゆる超硬合金等がその典型
的な例であるが、上記超硬合金に限らないこと、また鋳
造等によって製造された合金中にも該当する合金がある
ものである。(Prior Art) In wire-cut electric discharge machining, water or a water-based machining liquid containing water as a main component is usually used as a machining liquid, but in this case, a partial electrolysis occurs. In this case, as the work piece containing at least a part or more of metals and alloys that are relatively easily soluble by electrolysis as an active ingredient, for example,
Metal carbide such as WC-Co alloy, metal nitride, generally high hardness, high melting point particles such as metal boride Fe, Ni, Cr, Cu,
Metals such as Co, Zn, Al, Cd, Mn, Sn and Pb, so-called cemented carbides hardened by firing etc. using an alloy as a binder are typical examples, but not limited to the above cemented carbides. Also, there is a corresponding alloy among the alloys manufactured by casting or the like.
すなわち、加工液として水または水を主成分とする水系
加工液を用い、そして被加工物電極が電解により比較的
易溶解性の金属、合金を一部以上有効成分として含む材
料からなる、例えば焼成WC−Co合金を被加工物として放
電加工する場合で、その典型としては、焼成WC−Co合金
からなる被加工物を黄銅等の銅系合金からなるワイヤ電
極を用いてワイヤカット放電加工する場合があるが、従
来通常の加工用電源例えば、直流電圧源をトランジスタ
等のスイッチング素子のオン、オフにより間歇的な矩形
波電圧パルス列を生成供給する非蓄勢式加工用電源、直
流電圧源によってコンデンサを充電し、これを電極、被
加工物間の加工間隙に放電させる蓄勢式加工用電源、お
よびコンデンサの充電回路と放電回路の両方または何れ
か一方にスイッチング素子を挿入し、該スイッチング素
子のオン、オフを周期的に行なうか、コンデンサの充電
および放電さらには加工間隙の加工状態に応じて上記ス
イッチング素子のオン、オフを制御する形式の加工電源
等の何れの加工電源を使用した場合でも、加工間隙への
加工電圧印加極性は、通常、正極性（被加工物が正、ワ
イヤ電極が負）として印加されるのであり、被加工物の
ワイヤカット加工面は、その加工面の内部側から焼成合
金の結合材であるコバルトCoが、局部的にまたはほぼ全
体的にある深さ（例えば約0.01〜0.02mm前後）の部分迄
電解作用、陽極溶解作用等の電気化学作用によって溶出
してしまっていて、折角の加工処理が全く無駄となる
か、少なくとも品質上は勿論のこと、加工精度も所定以
下である等大きな問題があった。That is, water or a water-based working fluid containing water as a main component is used as the working fluid, and the workpiece electrode is made of a material containing a part or more of a metal or alloy which is relatively easily soluble by electrolysis as an active ingredient, for example, firing. In the case of electrical discharge machining of a WC-Co alloy as a work piece, typically, when performing a wire cut electrical discharge machining of a work piece made of a baked WC-Co alloy using a wire electrode made of a copper-based alloy such as brass. However, a conventional power supply for processing, for example, a non-accumulation type power supply for generating and supplying an intermittent rectangular wave voltage pulse train by turning on and off a switching element such as a transistor for a DC voltage source, a capacitor by a DC voltage source Charging power source for charging and discharging it into the machining gap between the electrode and the workpiece, and / or switching to the capacitor charging circuit and / or discharging circuit. Such as a machining power source of a type in which an element is inserted and the switching element is turned on and off periodically, or the switching element is turned on and off in accordance with the charging and discharging of the capacitor and the processing state of the processing gap. Regardless of which machining power source is used, the polarity of the machining voltage applied to the machining gap is normally applied as a positive polarity (workpiece is positive, wire electrode is negative) As for the surface, from the inner side of the processed surface, cobalt Co, which is the binder of the fired alloy, is locally or almost entirely deposited to a certain depth (for example, about 0.01 to 0.02 mm), and electrolysis and anodic dissolution are performed. Since it is eluted by the electrochemical action such as, the processing of the corners is completely wasted, or at least in terms of quality, the processing accuracy is below a predetermined level, which is a serious problem.
上記の如き各加工用電源の直流電圧源の出力無負荷電圧
は、少なくとも約80V乃至100Vまたはそれ以上で、約200
V前後というのは普通であり、約300V前後という物もど
ちらかといえば多い方であり、このため、正常放電加工
時における加工間隙の平均電圧または平均加工電圧が例
えば約150V前後ということも珍らしいことではなかっ
た。The output no-load voltage of the DC voltage source of each processing power source as described above is at least about 80V to 100V or higher, and is about 200V.
Around V is normal, and there are many cases with around 300V, so it is rare that the average voltage of the machining gap during normal electrical discharge machining or the average machining voltage is around 150V, for example. It wasn't like that.
例えば、特公昭41−9,399号公報記載の如き、一定の電
圧パルス幅または時間と、一定の電圧パルス間休止幅ま
たは時間を有する矩形波パルスの加工用電源の場合、電
圧パルス幅と休止幅の比を１（デューティーファクタ;1
/2）、供給電圧パルスの約50〜80％が放電する（短絡、
アーク等を含む、他は無負荷電圧パルス）状態がほぼ正
常加工状態として、今仮りに約80％の供給電圧パルスが
放電している状態とし、しかもその放電パルスの全て
が、各電圧パルスの立上りから少しの時間遅れも無く放
電を開始したと仮定し、また上記電圧パルス（放電パル
ス）の幅を従来通常のワイヤカット放電加工における数
μｓ、例えば約５μｓとする（従って休止幅も５μｓ）
と、加工液は通常水または水を主成分とする水系加工液
であるから、各放電パルスにおける放電電圧（放電維持
電圧）は約30V程度であって、（電圧パルスの無負荷電
圧値とほとんど無関係である。）さらに今また前記電圧
パルスの無負荷電圧を、例えば、約100Vとすると、加工
間隙の平均加工電圧は計算上約29Vということになる
が、実際は、例えば約30数Ｖまたはそれ以上と、計算上
の値よりもかなり高い値となる。For example, as described in JP-B-41-9,399, in the case of a power source for processing a rectangular wave pulse having a constant voltage pulse width or time and a constant voltage pulse pause or time, the voltage pulse width and the pause width The ratio is 1 (duty factor; 1
/ 2), about 50-80% of the supply voltage pulse is discharged (short circuit,
With the arc, etc., the other is a no-load voltage pulse state, the state is almost normal, and now about 80% of the supply voltage pulse is being discharged, and all of the discharge pulses are of each voltage pulse. It is assumed that the discharge is started without any time delay from the rise, and the width of the voltage pulse (discharge pulse) is set to several μs in the conventional normal wire-cut electric discharge machining, for example, about 5 μs (so the pause width is also 5 μs).
Since the working fluid is usually water or a water-based working fluid whose main component is water, the discharge voltage (discharge sustaining voltage) at each discharge pulse is about 30 V, and Moreover, if the no-load voltage of the voltage pulse is, for example, about 100 V, the average machining voltage of the machining gap is calculated to be about 29 V, but actually, for example, about 30 V or more. Above, it will be much higher than the calculated value.
平均加工電圧がこのように計算上の値よりも高い値にな
る主な理由の１つは、第８図（Ａ）に示す印加電圧パル
スに対し、ワイヤ電極と被加工物間の電圧は（Ｂ）によ
うになるからである。すなわち、当該印加電圧パルスに
よって放電が生じなかった場合に、ワイヤ電極と被加工
物間の浮遊容量等により供給電圧パルスによる電荷が残
留し、この電荷がワイヤ電極と被加工物間の浮遊容量、
等価抵抗やインダクタンス成分によって決定される時定
数に基づいて曲線Ｃに示すように放電すると共に、放電
が生じた場合は僅かで通常殆んど無視し得るものの、例
えば曲線Ｄに示すように、放電電圧から次第に電圧が低
下する放電曲線を描くからである。One of the main reasons why the average machining voltage becomes higher than the calculated value is that the voltage between the wire electrode and the workpiece is (for the applied voltage pulse shown in FIG. 8A). This is because B). That is, when discharge is not generated by the applied voltage pulse, the charge due to the supply voltage pulse remains due to the stray capacitance between the wire electrode and the workpiece, and this charge causes the stray capacitance between the wire electrode and the workpiece,
The discharge occurs as shown in the curve C based on the time constant determined by the equivalent resistance and the inductance component, and when the discharge occurs, it is small and usually almost negligible. This is because it draws a discharge curve in which the voltage gradually decreases from the voltage.
しかしてまた、前記平均加工電圧の値は、加工状態がア
ーク状等不良状態となる限界に近い放電割合（約80％）
を設定し、しかも、その各放電パルスが電圧パルスの印
加時から少しの時間遅れもなく放電を開始したものと仮
定しているだけでなく、デューティーファクタも比較的
小さく設定し、さらに、電圧パルスの無負荷電圧も低い
場合（100V）であるから、通常の正常加工状態のワイヤ
カット放電加工の平均加工電圧の半分またはそれ以下、
通常数分の１乃至それ以上の低い値であることが判る。
尤も、電圧パルスの幅が数10μｓ、例えば約30μｓ以上
で、棒状や型状電極等による加工液を水とする放電加工
では（加工液が水の場合、電圧パルス幅の広い領域では
電解作用が増し、良好な放電が維持できないし、上記電
解作用による弊害は避けられない。）、正常放電加工時
の各放電パルス中における放電電圧（放電維持電圧）は
約18V前後と低いものの、このような加工条件領域で
は、アーク放電とならないように供給電圧パルスに対す
る放電パルスの割合を減らすように制御したり、また、
デューティーファクタが通常の場合例えば3/4等大きく
設定されているから、前述の場合程ではないにしても、
加工間隙の平均加工電圧は前記29Vよりも相当高いのが
普通である。Again, the value of the average machining voltage is a discharge rate (about 80%) close to the limit at which the machining state becomes a defective state such as arc.
In addition to assuming that each discharge pulse has started discharge without any time delay from the application of the voltage pulse, the duty factor is set to be relatively small. Since the no-load voltage of is also low (100V), it is half or less of the average machining voltage of normal wire cutting EDM in the normal machining state.
It can be seen that it is usually a low value of a fraction or more.
However, the width of the voltage pulse is several tens of μs, for example, about 30 μs or more, and in the electric discharge machining that uses the machining fluid such as a rod-shaped or shaped electrode as water (when the machining fluid is water, the electrolysis action occurs in a wide voltage pulse region However, the discharge voltage (discharge sustaining voltage) during each discharge pulse during normal electrical discharge machining is as low as around 18V. In the processing condition area, control is performed to reduce the ratio of the discharge pulse to the supply voltage pulse so that arc discharge does not occur, and
In the normal case, the duty factor is set large, such as 3/4, so even if it is not the same as in the above case,
The average machining voltage of the machining gap is usually considerably higher than the above 29V.
そしてまた、上記放電電圧約18Vというのは、既に各放
電時等に電解作用がある割合で生じているからであっ
て、後述する本発明の目的とする電解作用を殆んど生じ
させないか、電解作用の極めて少ない放電加工用電源の
設定加工条件電圧パルス幅としては、上記約30μｓとい
うのは、相当程度上限に近いものということができる。Also, the discharge voltage of about 18V is because the electrolytic action has already occurred at a certain rate during each discharge, and does not cause the electrolytic action that is the object of the present invention described below. Regarding the set machining condition voltage pulse width of the electric power source for electric discharge machining, which has an extremely small electrolytic action, the above-mentioned about 30 μs can be said to be considerably close to the upper limit.
また、加工用電源として、例えば特公昭44−13,195号公
報記載の如き、電圧パルスの印加時間、特にその無負荷
電圧の時間が、各所定の休止幅の後印加される電圧パル
スによる放電開始の遅れに比例して増大する形式の矩系
波パルス加工電源では、加工間隙の平均加工電圧が前述
の公報記載のそれよりも増大することは明らかである。Further, as a machining power source, for example, as described in JP-B-44-13,195, the application time of a voltage pulse, in particular, the time of the no-load voltage, the discharge start by the voltage pulse applied after each predetermined pause width. It is clear that in the quadrature wave pulse machining power source of the type that increases in proportion to the delay, the average machining voltage in the machining gap increases more than that described in the above publication.
また、前に述べた蓄勢式加工電源や、コンデンサの充放
電両方の回路またはいずれか一方にオン、オフスイッチ
ング素子を挿入した形式の加工電源等においても、放電
時間が短縮される一方において、加工間隙への電圧印加
時間が増大する傾向となるから、かかる形式の加工用電
源の場合も前述のものよりも加工間隙の平均加工電圧が
高いのが普通である。Also, in the power storage type machining power supply described above, the machining power supply of the type in which the ON / OFF switching element is inserted in the circuit for charging / discharging both of the capacitors or one of them, while the discharge time is shortened, Since the voltage application time to the machining gap tends to increase, the average machining voltage of the machining gap is usually higher than that described above even in the case of such a type of power source for machining.
このような各種電源における電圧パルス印加時からの放
電開始の遅れは、加工間隙抵抗が印加電圧値に対して所
定値以上大きいことによるものであることは当然である
が、さらに間隙長に対する間隙抵抗の大きさ（加工液の
性状）や、放電加工回路部分の浮遊静電容量およびスイ
ッチング素子の静電容量等による電圧パルスの立上がり
の遅れ等も関係しているものである。It is natural that the delay of the discharge start from the application of the voltage pulse in such various power supplies is due to the machining gap resistance being larger than the applied voltage value by a predetermined value or more. Is also related to the size (characteristics of the machining liquid), the rising delay of the voltage pulse due to the floating electrostatic capacitance of the electric discharge machining circuit portion and the electrostatic capacitance of the switching element, and the like.
ところで、放電加工の加工間隙状態には種々の状態があ
るから、一概には言えないが、水または水を主成分とす
る液を加工液とする放電加工において、加工間隙の平均
加工電圧が高い程、加工間隙での電解作用およびその量
が増すであろうことは事実であり、そしてさらに加工間
隙で現に放電が行なわれていなくて、電圧が印加されて
いる時間（主として無負荷電圧印加時間）に電解作用お
よびその量がほぼ比例していることは極めて明らかなこ
とである。By the way, since there are various states of the machining gap in the electric discharge machining, it cannot be generally stated, but in electric discharge machining using water or a liquid containing water as a main component, the average machining voltage of the machining gap is high. It is true that the electrolytic action in the working gap and its amount will increase, and the time during which no voltage is actually applied and the voltage is applied (mainly the no-load voltage application time). It is quite clear that the electrolytic action and its amount are almost proportional to ().
また、印加電圧パルスに基づく放電中、特にその放電電
圧が例えば約25V前後またはそれ以上と比較的高い場合
には、放電と共にまたは同時に一部電解作用が生じてい
ると言われている。Further, it is said that during the discharge based on the applied voltage pulse, particularly when the discharge voltage is relatively high, for example, about 25 V or higher, a partial electrolytic action occurs simultaneously with or simultaneously with the discharge.
電解作用が少なく、従ってその結果として被加工物電極
構成材料中に含まれている他よりも易電解溶出性の金
属、合金の溶出を防止し、品質および加工精度の優れた
ワイヤカット放電加工を他に工夫を要することなく可能
となるワイヤカット放電加工用加工電源として、第１図
の回路図及び第２図の波形図に示すものが知られてい
る。第１図において、１はワイヤ電極、２は被加工物、
３はワイヤ電極１と被加工物２間に正極性の電圧を印加
する加工用の正極性電源、４は限流抵抗、５は前記電源
３の電圧の印加を制御するトランジスタやFET等からな
るスイッチング素子である。６はワイヤ電極１と被加工
物２間に負極性の電圧を印加する負極性電源、7,8はそ
れぞれその限流抵抗およびスイッチング素子であり、限
流抵抗７は前記加工用の回路に挿入される限流抵抗４の
抵抗値に比較して通常大きな値のものが選択される。９
は矩形波の電圧パルスａを発振する発振器、10は該発振
器９の出力パルスａの立上がりからt1の時間幅の電圧パ
ルスｂを発生させる単安定マルチバイブレータ回路（以
下単安定回路と称す）であり、該単安定回路10の出力パ
ルスｂが前記スイッチング素子５に加えられる。11は前
記単安定回路10の出力を反転させる反転素子、12は該反
転素子11の出力パルスｃの立上がりからt2の時間幅の出
力パルスｄを発生させる単安定回路で、該単安定回路12
の出力が前記負極性パルスを加える回路のスイッチング
素子８の制御信号として加えられる。Electrolytic action is small, and as a result, it is possible to prevent the elution of metals and alloys that are more easily electrolyzed than others contained in the work piece electrode constituent material, and to perform wire cut electrical discharge machining with excellent quality and machining accuracy. As a machining power source for wire-cut electric discharge machining that can be performed without any other contrivance, the one shown in the circuit diagram of FIG. 1 and the waveform diagram of FIG. 2 is known. In FIG. 1, 1 is a wire electrode, 2 is a workpiece,
3 is a positive power source for processing which applies a positive voltage between the wire electrode 1 and the workpiece 2, 4 is a current limiting resistor, and 5 is a transistor or FET which controls the application of the voltage of the power source 3 It is a switching element. Reference numeral 6 is a negative power source for applying a negative voltage between the wire electrode 1 and the workpiece 2, 7 and 8 are current limiting resistors and switching elements, respectively, and the current limiting resistor 7 is inserted in the processing circuit. A value that is normally larger than the resistance value of the current limiting resistor 4 is selected. 9
Is an oscillator which oscillates a rectangular wave voltage pulse a, and 10 is a monostable multivibrator circuit (hereinafter referred to as a monostable circuit) which generates a voltage pulse b having a time width of t 1 from the rise of the output pulse a of the oscillator 9. Yes, the output pulse b of the monostable circuit 10 is applied to the switching element 5. Reference numeral 11 is an inverting element that inverts the output of the monostable circuit 10, and 12 is a monostable circuit that generates an output pulse d having a time width of t 2 from the rise of the output pulse c of the inverting element 11.
Is applied as a control signal for the switching element 8 of the circuit for applying the negative polarity pulse.
第１図の回路の動作を第２図により説明する。発振器９
の出力パルスａの１周期の時間Ｔを例えば約10μｓ前後
またはそれ以内とすると、単安定回路10の出力パルスｂ
の時間t1は0.1〜９μｓ以内に設定され、単安定回路11
の出力パルスｄの時間t2は0.5μｓ〜（Ｔ−t1）μｓよ
りやや短い時間に設定される。また、正極性電源３の電
圧VOを例えば90Vとすると、負極性電源６の電圧VXは例
えば30〜70V程度に設定される。このような設定を前提
とし、第１図の回路は、発振器９の出力パルスａの立上
がりから単安定回路10はt1なる時間幅の出力パルスｂを
発生させ、これによりスイッチング素子５がその時間幅
だけオンとなり、ワイヤ電極１と被加工物２との間に正
極性電源３による正極性電圧パルスを印加する。この電
圧パルスの印加により放電が生じた場合のワイヤ電極１
と被加工物２との間の電圧Ｖの変化はE,Fで示す放電パ
ルスのようになり、放電が生じなかった場合はＧで示す
無負荷電圧パルスのようになる。単安定回路10の出力パ
ルスｂがオフとなると、反転回路11の出力はオンとなる
ので、その立上がりから単安定回路12からt2なる時間幅
の出力パルスｄが出力され、これによってスイッチング
素子８がオンとなり、今度はワイヤ電極１と被加工物２
との間に負極性電源６による負極性電圧パルスが加えら
れる。そして負極性の電圧パルスが加えられている時間
t2の間は加工間隙電圧（ワイヤ電極１に対する被加工物
２の電圧）は−VXとなるが、スイッチング素子８がオフ
になると、ワイヤ電極１と被加工物２との間等の放電加
工回路部分の浮遊容量や等価抵抗、インダクタンスによ
り決定される特定数に従がう曲線H,Iのように加工間隙
電圧が漸次低下し、まれにはＪのように放電が生じる。
従って、加工間隙に印加供給された正極性電圧パルスの
全数に対する最大放電率が例えば80％と仮定し、正極性
電圧VOに対する負極性電圧VXの値やパルスa,b,d等の時
間幅を適当な値に設定することにより、加工間隙の電圧
Ｖの平均値、すなわち平均加工電圧を零Ｖ以下または零
より低い所定値にすることができる。平均加工電圧を零
Ｖ以下または零Ｖよりも低い値にすれば、陽極溶解作用
が被加工物に作用せず、前記正極性パルスの時間幅が10
μｓ程度以下、通常数μｓ前後程度と短いこともあっ
て、被加工物中の合金中の金属の溶出を実質的に防止す
ることができる。The operation of the circuit shown in FIG. 1 will be described with reference to FIG. Oscillator 9
If the time T of one cycle of the output pulse a is about 10 μs or less, for example, the output pulse b of the monostable circuit 10
The time t 1 of is set within 0.1 to 9 μs, and the monostable circuit 11
The time t 2 of the output pulse d is set to a time slightly shorter than 0.5 μs to (T-t 1 ) μs. Further, when the voltage V O of the positive power source 3 is, for example, 90V, the voltage V X of the negative power source 6 is set to, for example, about 30 to 70V. Based on such a setting, in the circuit of FIG. 1, the monostable circuit 10 generates an output pulse b having a time width of t 1 from the rise of the output pulse a of the oscillator 9, whereby the switching element 5 has its time. Only the width is turned on, and a positive voltage pulse from the positive power source 3 is applied between the wire electrode 1 and the workpiece 2. Wire electrode 1 when discharge occurs due to the application of this voltage pulse
The change in the voltage V between the workpiece 2 and the workpiece 2 becomes like a discharge pulse indicated by E and F, and becomes like a no-load voltage pulse indicated by G when no discharge occurs. When the output pulse b of the monostable circuit 10 is turned off, the output of the inverting circuit 11 is turned on, so that the output pulse d of the time width t 2 is output from the monostable circuit 12 from the rising edge thereof, whereby the switching element 8 is turned on. Turns on, this time wire electrode 1 and work piece 2
A negative voltage pulse generated by the negative power source 6 is applied between and. And the time that the negative voltage pulse is applied
The machining gap voltage (voltage of the workpiece 2 with respect to the wire electrode 1) is −V X during t 2 , but when the switching element 8 is turned off, discharge between the wire electrode 1 and the workpiece 2 or the like occurs. The machining gap voltage gradually decreases as shown by curves H and I according to a specific number determined by the stray capacitance, equivalent resistance and inductance of the machining circuit portion, and in rare cases discharge occurs like J.
Therefore, assuming that the maximum discharge rate for the total number of positive voltage pulses applied and supplied to the machining gap is, for example, 80%, the value of the negative voltage V X with respect to the positive voltage V O and the time of the pulses a, b, d, etc. By setting the width to an appropriate value, the average value of the voltage V in the machining gap, that is, the average machining voltage can be set to a predetermined value lower than or equal to zero V or lower than zero. When the average machining voltage is set to a value lower than zero V or lower than zero V, the anodic dissolution action does not act on the workpiece, and the time width of the positive polarity pulse is 10
Since it is as short as about μs or less, usually about several μs, it is possible to substantially prevent the elution of the metal in the alloy in the workpiece.
（発明が解決しようとする問題点） しかしながら、このように各正極性電圧の印加後に必ず
負極性電圧を印加すれば、加える正極性電圧パルス数に
対して放電が生起した数（放電率）の如何に拘らず、負
極性電圧が印加されるわけであるから、放電率が大であ
る場合には加工間隙の平均加工電圧が低下し、放電開始
が遅れ、反対に、放電率が小さい場合には平均加工電圧
が高くなり、平均加工電圧を所定値以下に確実におさめ
ることができないという問題点がある。(Problems to be Solved by the Invention) However, if the negative polarity voltage is always applied after the application of each positive polarity voltage in this way, the number of discharges (discharging rate) with respect to the number of positive voltage pulses applied (discharge rate) Since the negative voltage is applied regardless of the discharge rate, the average machining voltage in the machining gap decreases when the discharge rate is large, and the discharge start is delayed. Conversely, when the discharge rate is small, However, there is a problem that the average processing voltage becomes high and the average processing voltage cannot be reliably kept below a predetermined value.
本発明は、上記問題点に鑑み、加工間隙における平均加
工電圧が好適な所定値以下の範囲に確実に抑制でき、被
加工物構成材料中に含まれている他よりも易溶解性の金
属、合金の溶出をほぼ完全に防止することができるワイ
ヤカット放電加工用電源装置を提供することを目的とす
る。In view of the above problems, the present invention can surely suppress the average machining voltage in the machining gap to a range of a preferred predetermined value or less, and a metal that is more easily soluble than the other contained in the workpiece constituent material, An object of the present invention is to provide a power supply device for wire cut electric discharge machining which can almost completely prevent elution of an alloy.
（問題点を解決するための手段） 本発明は、加工電極と被加工物との間隙に加工条件に応
じて設定された時間幅の電圧パルス又は放電パルスとな
る正極性電圧パルスを休止時間を置いて間歇的に印加
し、これにより両者間に放電を生じさせて加工を行うワ
イヤカット放電加工に於て、前記間隙に前記正極性電圧
パルスが印加される毎に、該電圧パルス印加により加工
間隙で放電が発生したか否かを該電圧パルス印加終了直
前から印加終了迄の間に検出する手段と、該検出手段に
より当該電圧パルスの印加終了時迄放電が発生していな
いことが検出された場合に、該検出信号と前記電圧パル
ス印加終了とに応じ前記加工間隙に次の正極性電圧パル
スの印加開始前に印加継続時間が終了する逆極性電圧パ
ルスを印加する手段とを設け、然らざる前記正極性電圧
パルスの印加により間隙に放電が発生していた場合に
は、該正極性電圧パルスの印加終了後の前記設定休止時
間の経過後に、次の前記正極性電圧パルスの印加を開始
させるように構成して成ることを特徴とする。(Means for Solving Problems) According to the present invention, a positive voltage pulse serving as a voltage pulse or a discharge pulse having a time width set in accordance with a machining condition is set in a gap between a machining electrode and a workpiece with a pause time. In the wire-cut electric discharge machining, in which the positive voltage pulse is applied to the gap, the machining is performed every time the positive voltage pulse is applied to the gap by applying the voltage pulse intermittently and thereby generating an electric discharge between the two. A means for detecting whether or not a discharge is generated in the gap between immediately before the end of the voltage pulse application and the end of the voltage pulse, and the detection means detects that the discharge is not generated until the end of the voltage pulse application. And a means for applying a reverse polarity voltage pulse whose application duration ends before the application of the next positive voltage pulse to the machining gap in response to the detection signal and the end of the voltage pulse application, Before the evil When discharge is generated in the gap due to the application of the positive polarity voltage pulse, the next application of the positive polarity voltage pulse is started after the set pause time has elapsed after the application of the positive polarity voltage pulse is completed. It is characterized in that it is configured as follows.
また本発明は、前記加工間隙の平均加工電圧が所定値以
下になるように前記逆極性電圧パルスの電圧又は印加継
続時間を制御する平均加工電圧検出及び制御手段とを設
けたことを特徴とする。Further, the present invention is characterized in that an average machining voltage detection and control means for controlling the voltage or the duration of application of the reverse polarity voltage pulse is provided so that the average machining voltage of the machining gap becomes a predetermined value or less. .
そして本発明においては、加工間隙における平均加工電
圧ができるだけ零Ｖに近くなるようにしたものである。Further, in the present invention, the average machining voltage in the machining gap is made as close to zero V as possible.
なお、本発明の適用可能な電源形式としては、前記特公
昭41−9,399号公報記載の形式のもの、およびコンデン
サの少なくとも放電回路にオン、オフスイッチング素子
を挿設した形式のものを利用しうるが、前記特公昭44−
13,195号公報記載のものも、例えばスイッチング素子の
オンにより加工間隙に直流電圧源の無負荷電圧を印加し
たとき、該電圧印加時より所望微小の時間内に加工間隙
で放電が開始されない場合には、一旦スイッチング素子
をオフとして電圧印加を中断し、所望、例えば休止幅と
同程度の中断時間の後にスイッチング素子を再びオンに
して加工間隙に次の電圧パルスを印加するようにして、
上記所望微小時間内に加工間隙で放電が開始されたもの
だけ所定時間幅の放電をさせるようにする等の手段を付
設すれば、ある程度の目的を達成させることができると
思惟されるが、充放電コンデンサの放電回路に被制御オ
ン、オフスイッチング素子が挿入されてない形式の加工
用電源によっては目的達成は困難であると思惟する。As the power source type to which the present invention is applicable, the type described in the above Japanese Patent Publication No. 41-9,399 and the type in which an on / off switching element is inserted in at least the discharge circuit of the capacitor can be used. However, the above Japanese Patent Publication No. 44-
No. 13,195 publication also, for example, when the no-load voltage of the DC voltage source is applied to the machining gap by turning on the switching element, when the discharge is not started in the machining gap within a desired minute time period than when the voltage is applied, , Once the switching element is turned off to interrupt the voltage application, and the desired voltage is applied, for example, the switching element is turned on again after a discontinuation time about the same as the pause width to apply the next voltage pulse to the machining gap.
It is thought that a certain degree of purpose can be achieved by additionally providing a means such as discharging a predetermined time width only for the discharge that has started in the machining gap within the desired minute time. We think that it is difficult to achieve the purpose by using a processing power supply that does not have controlled ON / OFF switching elements inserted in the discharge circuit of the discharge capacitor.
また、上記において、平均加工電圧を検出または測定す
るためには、所定複数個の電圧パルスが印加される期間
または所定時間内の間隙電圧のおおよその平均値と言う
ことになるが、その所定期間または時間とは、所定加工
条件において加工のための電圧パルスが通常少なくとも
２個以上（各電圧パルスと次の電圧パルスが印加される
迄の電圧パルス間休止時間を含む）、例えば、通常５〜
30個程度の電圧パルスが印加される期間または時間のこ
とであるが、設定加工条件によっては、例えば電圧パル
スの幅（時間）がある程度以上長い場合には、１個の電
圧パルスが印加される期間または時間（前または次の電
圧パルスまでの電圧パルス間休止時間を含む）程度に平
均加工電圧の検出時定数が設定されることがある。そし
てこの平均加工電圧の検出手段および回路としては、公
知の、または慣用の回路や素子等を適宜用いることがで
きる。Further, in the above, in order to detect or measure the average machining voltage, it can be said that it is an average value of the gap voltage within a predetermined period or a period in which a plurality of predetermined voltage pulses are applied. Or, the time is usually at least two or more voltage pulses for machining under a predetermined machining condition (including each voltage pulse and a dwell time between voltage pulses until the next voltage pulse is applied), for example, usually 5 to 5
It is a period or time during which about 30 voltage pulses are applied. Depending on the set processing conditions, for example, when the width (time) of the voltage pulse is longer than a certain length, one voltage pulse is applied. The detection time constant of the average machining voltage may be set to a period or time (including a pause time between voltage pulses until the previous or next voltage pulse). As the means and circuit for detecting the average processing voltage, a known or common circuit or element can be used as appropriate.
（実施例） 第３図は本発明の一の実施例であり、本実施例は、第１
図のように、正極性の電圧パルスの休止時に必ず負極性
の電圧パルスを加えるのではなく、印加正極性電圧パル
スによって加工間隙で放電が生じなかった場合にのみ負
極性の電圧パルスを加えるようにしたものである。第３
図において、13〜19で示すものが第１図の回路に対して
新たに加えられたもので、比較回路13は、ワイヤ電極１
に対する被加工物の電圧Ｖと基準電圧Ｖ′（この基準電
圧Ｖ′は、放電電圧より高く、かつ印加電圧Ｖよりも低
く設定される）とを比較し、Ｖ≧Ｖ′であれば出力ｈを
「１」とし、Ｖ＜Ｖ′であれば「０」とするものであ
る。単安定回路14、反転回路15、単安定回路16およびア
ンド回路17は、スイッチング素子５がオフとなっている
間の途中の時点で前記比較回路13の出力ｈを監視するた
めに設けられたもので、前位の単安定回路14の出力ｅは
単安定回路10の出力ｂの立上がりに同期して立上がり、
その設定時間t3は単安定回路10の設定時間t1の30〜70％
程度に設定され、後位の単安定回路16は前位の単安定回
路14の出力ｅの立下がり、すなわち反転回路15の出力ｆ
の立上がりに同期してオンとなり、設定時間t4は前記設
定時間t1の数分の１ないしは（t1−t3）程度に設定され
る。Ｒ−Ｓフリップフロップ回路18はアンド回路17の出
力がオンとなる場合、すなわち、放電が生じなかった場
合にのみセットされ、出力ｊが「１」となる。また、該
Ｒ−Ｓフリップフロップ回路18は前記単安定回路14の出
力ｅによりリセットされる。アンド回路19は、Ｒ−Ｓフ
リップフロップ回路18の出力ｊが「１」である場合にの
み単安定回路12の出力ｄをスイッチング素子８を加え、
オンとする。従って、第４図の波形図にも示すように、
スイッチング素子８は、正極性の電圧パルスの休止時間
中に、直前の正極性電圧パルスによって放電が生じなか
ったと想定される場合にのみオンとなり、加工間隙に負
極性の電圧パルスが加えられる。(Embodiment) FIG. 3 shows one embodiment of the present invention.
As shown in the figure, do not always apply the negative voltage pulse when the positive voltage pulse is stopped, but apply the negative voltage pulse only when the applied positive voltage pulse does not cause discharge in the machining gap. It is the one. Third
In the figure, those indicated by 13 to 19 are newly added to the circuit of FIG.
The voltage V of the work piece to the reference voltage V '(the reference voltage V'is set higher than the discharge voltage and lower than the applied voltage V), and if V≥V', the output h Is set to "1", and if V <V 'is set to "0". The monostable circuit 14, the inverting circuit 15, the monostable circuit 16, and the AND circuit 17 are provided to monitor the output h of the comparison circuit 13 at a midpoint while the switching element 5 is off. Then, the output e of the preceding monostable circuit 14 rises in synchronization with the rise of the output b of the monostable circuit 10,
The set time t 3 is 30 to 70% of the set time t 1 of the monostable circuit 10.
The output of the monostable circuit 14 of the preceding stage falls, that is, the output f of the inverting circuit 15
Synchronization with turned on the rising edge of, the set time t 4 is set to about a fraction of or (t 1 -t 3) of the set time t 1. The RS flip-flop circuit 18 is set only when the output of the AND circuit 17 is turned on, that is, when the discharge is not generated, and the output j becomes "1". The RS flip-flop circuit 18 is reset by the output e of the monostable circuit 14. The AND circuit 19 adds the switching element 8 to the output d of the monostable circuit 12 only when the output j of the RS flip-flop circuit 18 is "1".
Turn on. Therefore, as shown in the waveform diagram of FIG.
The switching element 8 is turned on only during the rest period of the positive voltage pulse when it is assumed that no discharge has occurred due to the immediately previous positive voltage pulse, and the negative voltage pulse is applied to the machining gap.
なお、第３図の実施例の場合には、第１図の場合に比較
し、発振器９の１周期の時間Ｔよりもスイッチング素子
５のオンとなる時間t1を相対的に短かくし、かつ負極性
電源６の電圧を高くすると共に、スイッチング素子８の
オンとなる時間を比較的長くすることにより、加工間隙
に印加した正極性電圧パルスによって放電が行なわれな
い場合は勿論のこと、加工間隙に印加供給された正極性
電圧パルスの全パルス数に対する放電率が約80％の最大
放電率の際にも加工間隙の平均加工電圧が零Ｖに近い所
定範囲内におさまることを可能にしたものである。な
お、放電が生じたか否かの判定は、加工間隙電圧ではな
く放電電流の有無によって行なってもよい。In the case of the embodiment shown in FIG. 3, as compared with the case shown in FIG. 1, the time t 1 for turning on the switching element 5 is made relatively shorter than the time T of one cycle of the oscillator 9, and By increasing the voltage of the negative polarity power supply 6 and making the switching element 8 ON for a relatively long time, not only when the positive polarity voltage pulse applied to the machining gap does not cause discharge, but also the machining gap. The average machining voltage of the machining gap can be kept within a predetermined range close to 0V even when the maximum discharge rate is about 80% of the total number of positive voltage pulses applied and supplied to the Is. The determination as to whether or not the discharge has occurred may be made based on the presence or absence of the discharge current instead of the machining gap voltage.
第５図は本発明の他の実施例であり、加工間隙の平均加
工電圧Ｖを積分回路等により構成される平均加工電圧検
出回路20で検出し、その値に応じて平均加工電圧Ｖが零
Ｖに近いある範囲内におさまるように、検出回路20によ
る電圧検出値に応じて制御信号を出力する制御回路21に
よって負極性電源６の電圧値を制御すること、および該
制御回路21によって前記単安定回路12の設定時間t2を可
変することの少なくともいずれかを行なうようにしたも
のである。このような構成とすれば、平均加工電圧の範
囲を好適な狭い範囲に容易におさめることができる。な
おこの回路において、スイッチング素子５とスイッチン
グ素子８のオンとなる時間は、前記特公昭47−46,156号
公報記載の回路構成、その他により発振器９の周期の制
限を受けず、それぞれ任意に独立して可変設定できるよ
うにしてもよい。また、平均加工電圧検出回路20の代わ
りに、単安定回路10の出力パルス数に対するＲ−Ｓフリ
ップフロップ回路18の出力パルス数、すなわち放電率を
検出する回路を設け、その回路の出力によって負極性電
源６の電圧や単安定回路12の設定時間t2を可変するよう
にすることによっても同様の作用を果たすことができ
る。FIG. 5 shows another embodiment of the present invention, in which the average machining voltage V of the machining gap is detected by the average machining voltage detection circuit 20 constituted by an integrating circuit or the like, and the average machining voltage V is zero according to the value. The voltage value of the negative power supply 6 is controlled by the control circuit 21 that outputs a control signal in accordance with the voltage detection value by the detection circuit 20 so that the voltage value falls within a certain range close to V. At least one of changing the set time t 2 of the stabilizing circuit 12 is performed. With such a configuration, the range of the average processing voltage can be easily reduced to a suitable narrow range. In this circuit, the time when the switching element 5 and the switching element 8 are turned on is not restricted by the cycle of the oscillator 9 due to the circuit configuration described in Japanese Patent Publication No. 47-46,156 and other factors, and is independently set independently. It may be variably set. Further, instead of the average machining voltage detection circuit 20, a circuit for detecting the number of output pulses of the RS flip-flop circuit 18 with respect to the number of output pulses of the monostable circuit 10, that is, the discharge rate is provided, and the negative polarity is obtained by the output of the circuit. The same effect can be achieved by varying the voltage of the power source 6 and the set time t 2 of the monostable circuit 12.
上記各実施例においては、正極性電圧パルスと負極性電
圧パルスを、正極性電圧パルスの所定設定間幅t1終了時
におけるカットオフ時に同期して加工間隙に印加を開始
する構成となっているが、例えば前記公報記載の如く所
定の設定された時間幅の遅延時間を介在させるようにし
てもよい。In each of the above embodiments, the positive voltage pulse and the negative voltage pulse are applied to the machining gap in synchronization with the cutoff at the end of the predetermined set width t 1 of the positive voltage pulse. However, for example, as described in the above publication, a delay time of a predetermined set time width may be interposed.
そして、上記負極性の電圧パルスの無負荷電圧値やその
時点の加工間隙の状態等にもよるが、上記印加された負
極性の電圧パルスによって加工間隙で放電が発生し、該
負極性の電圧パルスに基づく（負極性）放電加工が行な
われることも少なくないものであり、従ってこの負極性
の電圧パルスに基づく放電加工特性は、正極性電圧パル
スに基づく放電加工特性を大きく変更させることがない
ような放電パルス条件とすることが望ましいものであ
る。Then, depending on the no-load voltage value of the negative voltage pulse and the state of the machining gap at that time, the negative voltage pulse causes discharge in the machining gap, and the negative voltage It is not uncommon for pulse-based (negative polarity) electrical discharge machining to be performed, so the electrical discharge machining characteristic based on this negative voltage pulse does not significantly change the electrical discharge machining characteristic based on the positive voltage pulse. It is desirable to set such discharge pulse conditions.
上記第３図の実施例においては、正極性電圧パルスと負
極性の電圧パルスを供給するものとしては、加工用の電
圧パルスを生成供給する正極性電源３、源流抵抗４およ
びスイッチング素子５等とは別に設けた負極性電源６、
限流抵抗７およびスイッチング素子８等により負極性の
電圧パルスを印加する構成としたが、加工用電圧パルス
電源を構成する正極性電源３、限流抵抗４およびスイッ
チング素子５の電圧パルス出力と被加工物２とからなる
加工間隙との間に電子極性切換回路を設け、上記正極性
電源３、限流抵抗４およびスイッチング素子５の一部ま
たは全部を使用して、上記所望の負極性の電圧パルス
を、正極性電圧パルス間の所望の時点において加工間隙
に供給印加するように構成することができるものであ
り、その際のスイチング素子５のオン、オフの切換制御
およびタイミングや前記電子切換回路の切換タイミング
および各切換状態の保持時間制御等は当業者が目的に応
じて所望に設定できるものである。また、本発明は先に
詳述したように、正極性電圧パルスの幅が加工間隙に依
存する特公昭44−13,195号公報記載の電源や、コンデン
サの充放電回路の一方または両方にスイッチング素子を
挿入した蓄勢式の加工電源等に対しても適用が可能なも
のである。In the embodiment shown in FIG. 3, the positive voltage pulse and the negative voltage pulse are supplied by a positive power source 3, a source resistance 4 and a switching element 5 which generate and supply a voltage pulse for processing. Separately provided negative power source 6,
Although the negative voltage pulse is applied by the current limiting resistor 7 and the switching element 8 and the like, the voltage pulse output of the positive power source 3, the current limiting resistor 4 and the switching element 5 which form the processing voltage pulse power source An electronic polarity switching circuit is provided between the workpiece 2 and a machining gap, and a part of or all of the positive power source 3, the current limiting resistor 4 and the switching element 5 is used to generate the desired negative voltage. The pulse can be configured to be supplied and applied to the machining gap at a desired time point between the positive voltage pulses, and the switching control and timing of the switching element 5 at that time and the electronic switching circuit. Those skilled in the art can arbitrarily set the switching timing and control of the holding time of each switching state according to the purpose. Further, as described in detail above, the present invention provides a power source described in Japanese Patent Publication No. 44-13195, in which the width of the positive voltage pulse depends on the machining gap, and a switching element in one or both of the charge and discharge circuits of the capacitor. It can also be applied to an inserted energy storage type machining power source.
（発明の効果） 以上述べたように、本発明においては、正極性電圧パル
ス間の休止時間に、該電圧パルスによる放電が生じなか
った場合に負極性の電圧パルスを印加することにより、
放電率の如何に拘らず、加工間隙における平均加工電圧
が零Ｖに近い所定範囲内に確実におさまることを可能に
したものであり、これにより、被加工物構成材料中に含
まれている他よりも易電解溶出性の金属、合金の溶出を
ほぼ完全に防止することができる。また、前記加工間隙
の平均加工電圧が所定値以下になるように前記逆極性電
圧パルスの電圧又は印加継続時間を制御する平均加工電
圧検出及び制御手段とを設けたので、さらに平均加工電
圧を所定値内に正確におさめることができる。(Effects of the Invention) As described above, in the present invention, by applying the negative voltage pulse when the discharge due to the voltage pulse does not occur during the pause time between the positive voltage pulses,
This makes it possible to ensure that the average machining voltage in the machining gap falls within a predetermined range close to zero V regardless of the discharge rate. It is possible to almost completely prevent elution of metals and alloys that are more easily electrolyzed. Further, since the average machining voltage detection and control means for controlling the voltage of the reverse polarity voltage pulse or the application duration is provided so that the average machining voltage of the machining gap becomes equal to or less than the predetermined value, the average machining voltage is further specified. It can be set exactly within the value.
第１図は従来例を示す回路図、第２図は第１図の動作説
明に供する波形図、第３図は本発明の他の実施例を示す
回路図、第４図は第３図の動作説明に供する波形図、第
５図は本発明のさらに他の実施例を示す回路図、第６図
は従来のワイヤカット放電加工における問題点を説明す
る波形図である。FIG. 1 is a circuit diagram showing a conventional example, FIG. 2 is a waveform diagram used to explain the operation of FIG. 1, FIG. 3 is a circuit diagram showing another embodiment of the present invention, and FIG. FIG. 5 is a waveform diagram for explaining the operation, FIG. 5 is a circuit diagram showing still another embodiment of the present invention, and FIG. 6 is a waveform diagram for explaining problems in the conventional wire cut electric discharge machining.
Claims (2)
応じて設定された時間幅の電圧パルス又は放電パルスと
なる正極性電圧パルスを休止時間を置いて間歇的に印加
し、これにより両者間に放電を生じさせて加工を行うワ
イヤカット放電加工に於て、 前記間隙に前記正極性電圧パルスが印加される毎に、該
電圧パルス印加により加工間隙で放電が発生したか否か
を該電圧パルス印加終了直前から印加終了迄の間に検出
する手段と、 該検出手段により当該電圧パルスの印加終了時迄放電が
発生していないことが検出された場合に、該検出信号と
前記電圧パルス印加終了とに応じ前記加工間隙に次の正
極性電圧パルスの印加開始前に印加継続時間が終了する
逆極性電圧パルスを印加する手段とを設けると共に、 前記正極性電圧パルスの印加により間隙に放電が発生し
ていた場合には、該正極性電圧パルスの印加終了後の前
記設定休止時間の経過後に、次の前記正極性電圧パルス
の印加を開始させるように構成して成る ことを特徴とするワイヤカット放電加工用電源装置。1. A voltage pulse having a time width set according to the processing conditions or a positive voltage pulse serving as a discharge pulse is intermittently applied to a gap between the processing electrode and the workpiece with a pause, and In wire-cut electric discharge machining, in which electric discharge is generated between the two to perform machining, each time the positive voltage pulse is applied to the gap, whether or not electric discharge is generated in the machining gap by applying the voltage pulse Means for detecting between the voltage pulse application end and the voltage application end, and the detection signal and the detection signal when the detection means detects that discharge has not occurred until the voltage pulse application end. A means for applying a reverse polarity voltage pulse whose application duration is ended before the application of the next positive polarity voltage pulse to the machining gap in response to the completion of the voltage pulse application is provided, and the positive polarity voltage pulse is applied. When a discharge is generated in the positive gap, the next application of the positive voltage pulse is started after the set pause time has elapsed after the application of the positive voltage pulse. Power supply device for wire cut electrical discharge machining.
応じて設定された時間幅の電圧パルス又は放電パルスと
なる正極性電圧パルスを休止時間を置いて間歇的に印加
し、これにより両者間に放電を生じさせて加工を行うワ
イヤカット放電加工に於て、 前記間隙に前記正極性電圧パルスが印加される毎に、該
電圧パルス印加により加工間隙で放電が発生したか否か
を該電圧パルス印加終了直前から印加終了迄の間に検出
する手段と、 該検出手段により当該電圧パルスの印加終了時迄放電が
発生していないことが検出された場合に、該検出信号と
前記電圧パルス印加終了とに応じ前記加工間隙に次の正
極性電圧パルスの印加開始前に印加継続時間が終了する
逆極性電圧パルスを印加する手段とを設けると共に、 前記正極性電圧パルスの印加により間隙に放電が発生し
ていた場合には、該正極性電圧パルスの印加終了後の前
記設定休止時間の経過後に、次の前記正極性電圧パルス
の印加を開始させるように構成して成り、 かつ、前記加工間隙の平均加工電圧が所定値以下になる
ように前記逆極性電圧パルスの電圧又は印加継続時間を
制御する平均加工電圧検出及び制御手段とを設けた ことを特徴とするワイヤカット放電加工用電源装置。2. A voltage pulse having a time width set according to the machining conditions or a positive voltage pulse serving as a discharge pulse is intermittently applied to the gap between the machining electrode and the workpiece with a pause, and In wire-cut electric discharge machining, in which electric discharge is generated between the two to perform machining, each time the positive voltage pulse is applied to the gap, whether or not electric discharge is generated in the machining gap by applying the voltage pulse Means for detecting between the voltage pulse application end and the voltage application end, and the detection signal and the detection signal when the detection means detects that discharge has not occurred until the voltage pulse application end. A means for applying a reverse polarity voltage pulse whose application duration is ended before the application of the next positive polarity voltage pulse to the machining gap in response to the completion of the voltage pulse application is provided, and the positive polarity voltage pulse is applied. When a discharge is generated in the gap, it is configured to start the application of the next positive voltage pulse after the lapse of the set rest time after the application of the positive voltage pulse, Also, an average machining voltage detection and control means for controlling the voltage of the reverse polarity voltage pulse or the duration of application is provided so that the average machining voltage of the machining gap becomes a predetermined value or less. Power supply for processing.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60032734A JPH0716827B2 (en) | 1985-02-22 | 1985-02-22 | Power supply for wire cut electrical discharge machining |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60032734A JPH0716827B2 (en) | 1985-02-22 | 1985-02-22 | Power supply for wire cut electrical discharge machining |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS61192415A JPS61192415A (en) | 1986-08-27 |
| JPH0716827B2 true JPH0716827B2 (en) | 1995-03-01 |
Family
ID=12367062
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP60032734A Expired - Fee Related JPH0716827B2 (en) | 1985-02-22 | 1985-02-22 | Power supply for wire cut electrical discharge machining |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0716827B2 (en) |
Families Citing this family (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS63102825A (en) * | 1986-10-20 | 1988-05-07 | Fanuc Ltd | Power source for electric discharge machining |
| JPH03104517A (en) * | 1989-09-18 | 1991-05-01 | Mitsubishi Electric Corp | Power source device for electric discharge processing |
| JPH03208520A (en) * | 1990-01-05 | 1991-09-11 | Makino Milling Mach Co Ltd | Machining pulse control method and device for electric discharge machine |
| JP2939310B2 (en) * | 1990-08-14 | 1999-08-25 | 株式会社ソディック | Electric discharge machine |
| JP2705427B2 (en) * | 1992-02-07 | 1998-01-28 | 三菱電機株式会社 | Electric discharge machine |
| US5416290A (en) * | 1992-10-08 | 1995-05-16 | Mitsubishi Denki Kabushiki Kaisha | Electric discharge machine power supply circuit |
| US6727455B1 (en) * | 2000-06-06 | 2004-04-27 | Mitsubishi Denki Kabushiki Kaisha | Power supply system for applying a voltage of both positive and negative polarities in electric discharge machining |
| JP4623756B2 (en) * | 2008-06-03 | 2011-02-02 | 株式会社ソディック | Electric discharge machine and electric discharge machining method |
| JP5137711B2 (en) * | 2008-06-24 | 2013-02-06 | 三菱電機株式会社 | Power supply device for wire electric discharge machine |
| JP6514163B2 (en) | 2016-09-01 | 2019-05-15 | ファナック株式会社 | Wire electric discharge machine |
| JP6740390B2 (en) * | 2019-01-08 | 2020-08-12 | ファナック株式会社 | Wire electric discharge machine |
| EP3950200B1 (en) * | 2020-08-07 | 2023-05-03 | Agie Charmilles SA | Method for high-speed wire cutting |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5656341A (en) * | 1979-10-05 | 1981-05-18 | Fanuc Ltd | Power source for wire cut electric discharge machining |
| JPS59152017A (en) * | 1983-02-15 | 1984-08-30 | Inoue Japax Res Inc | Electrical discharge processing device |
-
1985
- 1985-02-22 JP JP60032734A patent/JPH0716827B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPS61192415A (en) | 1986-08-27 |
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