JP3311530B2 - Electric discharge machine - Google Patents
Electric discharge machineInfo
- Publication number
- JP3311530B2 JP3311530B2 JP33470394A JP33470394A JP3311530B2 JP 3311530 B2 JP3311530 B2 JP 3311530B2 JP 33470394 A JP33470394 A JP 33470394A JP 33470394 A JP33470394 A JP 33470394A JP 3311530 B2 JP3311530 B2 JP 3311530B2
- Authority
- JP
- Japan
- Prior art keywords
- discharge
- circuit
- voltage
- machining
- discharge gap
- 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
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- Electrical Discharge Machining, Electrochemical Machining, And Combined Machining (AREA)
Description
【0001】[0001]
【産業上の利用分野】本発明は、放電加工用の放電間
隙、放電間隙状態、又は放電状態若しくは放電加工状態
(以下「放電間隙の放電状態」という。)検出回路、詳
しくは仕上げ加工用の放電間隙の放電状態検出回路、特
に前記仕上げ加工用の電源として高周波交流電圧源を用
いた場合の放電状態検出回路、及び該放電状態検出回路
の検出信号により加工のための各種制御、例えばサーボ
送り制御を行なう放電加工装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discharge gap for electric discharge machining, a discharge gap state, or a discharge state or a discharge machining state (hereinafter referred to as a "discharge state of a discharge gap"). A discharge state detection circuit for a discharge gap, particularly a discharge state detection circuit when a high-frequency AC voltage source is used as a power supply for the finishing processing, and various controls for processing by a detection signal of the discharge state detection circuit, for example, servo feed The present invention relates to an electric discharge machine for performing control.
【0002】[0002]
【従来の技術】 図7は、従来の放電間隙の放電状態検
出回路、及び該放電状態検出回路によって検出された信
号により放電加工のためのサーボ送り制御を行なう1回
路例の概略のブロックダイアグラム説明図を示すもの
で、30は後述する本発明者等の開発に係わる仕上げ加
工用電源、1はワイヤ放電加工用ワイヤ電極又は穿孔・
型彫加工用総型電極、3は被加工体、31は放電間隙電
圧検出用分圧回路、32は検出分圧電圧を,必要に応じ
半波又は全波整流した後増幅する演算増幅器から成る反
転増幅回路、33は増幅電圧を整流積分する積分回路、
34は積分電圧の反転増幅回路で可変抵抗34Aの調整
によりサーボゲイン(利得)を調整する利得調整回路、
35は利得が調整された増幅電圧のサンプルホールド増
幅器、36はサンプルホールドされた増幅電圧をデジタ
ル信号に変換するA/D変換器、37は変換デジタル信
号の次段のNC装置への入出力回路であって、発光素子
と受光素子とから成る回路絶縁用のフォトカプラ、38
は同時2軸以上の4軸又は3軸の制御が可能な放電加工
用NC制御装置やマイクロコンピュータ等を内蔵する制
御装置、39はモータドライバ、40はXY2軸、Z
軸、あるいはさらにテーパ加工用UV2軸のサーボモー
タである。2. Description of the Related Art FIG. 7 is a schematic block diagram of an example of a conventional circuit for detecting a discharge state in a discharge gap and a circuit for performing servo feed control for electric discharge machining based on a signal detected by the circuit. shows the FIG, 30 is present inventors engaged Waru finishing up machining power source for the development of which will be described later, 1 wire electrode or piercing and wire EDM
A die electrode for engraving, 3 is a workpiece, 31 is a voltage dividing circuit for detecting a discharge gap voltage, and 32 is an operational amplifier that amplifies the detected divided voltage after half-wave or full-wave rectification as necessary. An inverting amplifier circuit; 33, an integrating circuit for rectifying and integrating the amplified voltage;
34 is an inverting amplification circuit for integrating voltage, a gain adjustment circuit for adjusting a servo gain (gain) by adjusting a variable resistor 34A,
35 is a sample and hold amplifier for the amplified voltage whose gain has been adjusted, 36 is an A / D converter for converting the sampled and held amplified voltage into a digital signal, and 37 is an input / output circuit of the converted digital signal to the next-stage NC device. 38. A circuit isolating photocoupler comprising a light emitting element and a light receiving element,
Is a control device having a built-in microcomputer such as an NC controller or a microcomputer for electric discharge machining capable of simultaneously controlling four or three axes of two or more axes, 39 is a motor driver, 40 is XY two axes, Z
This is a two-axis servo motor for shaft or, further, taper processing.
【0003】前記30は、放電加工に於て、ほぼ最終的
に仕上げ加工を行なう仕上げ加工用電源、特に後で詳し
く説明するが、例えば本発明特許出願人の先願発明に係
る下記特許出願 1.[出願日] 平成6年2月18日提出の特許願 [整理番号] P94−004 [出願番号] 平成6年特許願第59,777号 [発明の名称] ワイヤ放電加工用電源回路及び電源用
回路装置 2.[出願日] 平成6年3月23日提出の特許願 [整理番号] P94−032 [出願番号] 平成6年特許願第92,836号 [発明の名称] ワイヤ放電加工方法及びワイヤ放電加
工用電源回路 等に記載説明した、必要に応じ、1サイクル毎に休止時
間を有せしめ得る高周波交流電圧源から成る仕上げ加工
用電源で、その出力高周波交流電圧は、周波数が大凡1
MHz前後又はそれ以上の高周波で、図示しない加工液
が両者間に流通介在せしめられる加工用電極1と被加工
体3間の微細な放電間隙に印加されて放電し、前段階迄
の中仕上げ加工等により、ほぼ所定の寸法・形状精度に
仕上げられた被加工体3の加工面の主として面粗度改善
(約3.5〜1μmRmax又はこれ以上迄)の仕上げ
加工をするものである。[0003] Reference numeral 30 denotes a finishing power supply for performing a finishing work almost finally in electric discharge machining, and will be described in detail later in particular. For example, the following patent application 1 relates to the prior application of the present applicant. . [Application date] Patent application filed on February 18, 1994 [Reference number] P94-004 [Application number] 1994 Patent application No. 59,777 [Title of the invention] Power supply circuit for wire electric discharge machining and power supply Circuit device 2. [Application Date] Patent application filed on March 23, 1994 [Reference number] P94-032 [Application number] 1994 Patent Application No. 92,836 [Title of Invention] Wire electric discharge machining method and wire electric discharge machining A finishing power supply comprising a high-frequency AC voltage source described in a power supply circuit or the like, which can have a pause for each cycle as necessary, and the output high-frequency AC voltage has a frequency of about 1
At a high frequency of about MHz or more, a working fluid (not shown) is applied to a fine discharge gap between the working electrode 1 and the work piece 3 in which the working fluid flows and intervenes between the two, and discharges, and a semi-finishing process up to the previous stage. In this way, finishing processing is performed mainly for improving the surface roughness (approximately 3.5 to 1 μm Rmax or more) of the processed surface of the workpiece 3 finished to approximately the predetermined size and shape accuracy.
【0004】而して、前述のような仕上げ加工や、該仕
上げ加工に到る迄の最初の荒加工又はファーストカット
加工、次段の中加工又はセカンドカット加工、あるいは
さらに中仕上げ加工又はサードカット加工に於ける加工
のためのサーボ送り制御の放電間隙の放電状態検出回路
又は検出調整回路としては多種多様な物があるが、その
1例は、前述図7の如き構成のものであり、検出放電間
隙電圧は、分圧回路31からA/D変換回路36迄で、
所望ゲインに応じたデジタル信号に変換され、フォトカ
プラ37を介し制御装置38に送られて演算され、制御
装置38内のNC装置に入力設定手段38Aにより、加
工の目的等に応じ、作業者により入力された所望設定電
圧又は基準電圧との偏差に応じ、通常は偏差零で、送り
速度が零で、その送り方向が反転するゼロメソッドサー
ボ、又は前記偏差零で設定加工条件の加工速度に応じた
送り速度が設定される減速サーボ等のサーボ制御方式の
加工送りとなるようサーボモータ40のドライバ39に
ドライブ制御信号が供給されている。[0004] Thus, the above-mentioned finishing, the first roughing or first-cutting up to the finishing, the next middle- or second-cutting, or the further semi-finishing or third-cutting There are various types of discharge state detection circuits or detection adjustment circuits for the discharge gap of the servo feed control for machining in machining, and one example thereof has a configuration as shown in FIG. The discharge gap voltage is from the voltage dividing circuit 31 to the A / D conversion circuit 36.
The digital signal is converted into a digital signal corresponding to a desired gain, sent to a control device 38 via a photocoupler 37 and calculated, and input to an NC device in the control device 38 by an input setting means 38A according to a processing purpose or the like. According to the deviation from the input desired set voltage or reference voltage, usually zero deviation, zero feed servo, zero method servo in which the feed direction is reversed, or the deviation zero according to the processing speed of the set processing conditions The drive control signal is supplied to the driver 39 of the servo motor 40 so that the machining feed of the servo control system such as the deceleration servo in which the feed speed is set is performed.
【0005】[0005]
【発明が解決しようとする課題】ところで、斯種高周波
交流電圧源による仕上げ加工には、放電間隙、及び該放
電間隙廻りの構造物や加工用電圧源給電回路部分等が有
する浮遊静電容量の値を仕上げ加工の目的に従い相応に
小さくしないと、浮遊容量の充放電による高い放電ピー
ク電流の放電が混じることになり、該高ピークの放電が
混じると、加工面が荒れ、目的とする加工面粗度(約
3.5〜1μmRmax、又はそれ以上)に仕上がらな
いことになる。又、前記のように浮遊容量が充分小さく
ないと、加えた高周波交流電圧が減衰し、そうでなくて
も加工効率がよくない乃至は加工効率が容易に著しく低
下することがある高周波交流電圧源による面粗度改善の
仕上げ加工の加工効率を低下させることになるから避け
る必要がある。By the way, in finishing machining using such a high-frequency AC voltage source, the discharge gap, the structure around the discharge gap, and the floating capacitance of the machining voltage source power supply circuit and the like are included. If the value is not appropriately reduced according to the purpose of the finishing process, a discharge of a high discharge peak current due to charging / discharging of the stray capacitance will be mixed. Roughness (approximately 3.5-1 μm Rmax or more) will not be achieved. Also, as described above, if the stray capacitance is not sufficiently small, the applied high-frequency AC voltage is attenuated, otherwise the processing efficiency is poor or the processing efficiency is easily reduced significantly. Therefore, it is necessary to avoid the finish efficiency of the finishing process for improving the surface roughness because the process efficiency is lowered.
【0006】ところが、前記図7の従来例のサーボ送り
制御の放電状態検出回路を備えた仕上げ加工回路によれ
ば、電極・被加工体間の放電間隙及びその廻りと、高周
波交流電圧源30、及び該電圧源30から放電間隙迄の
給電回路等の浮遊静電容量を工夫等して所望に低減せし
め得たとしても、前記放電間隙には加工用電源の制御や
加工送りのためのサーボ制御用放電状態検出回路とし
て、前記分圧回路31からA/D変換回路36迄の、通
常電源装置のボックス内にある電子回路が接続されてい
て、該電子回路は勿論、その回路構成や構造等によるも
のの、大凡約100〜1000PF前後の浮遊容量を有
しており、該検出回路部分の浮遊容量は、前述した高周
波交流電圧源による加工面粗度改善の仕上げ加工に際し
ての障害となるものである。そして、又、斯種高周波交
流電圧源を加工用電源とする仕上げ放電加工では、前述
の如く約1MHz前後又はそれ以上の高周波で、かつ後
述するように主として加工効率上可成りの高電圧、例え
ば、正負の波高値電圧間で約350〜500Vであっ
て、その放電間隙から放電状態検出回路の同軸ケーブル
等のリード線が引き出され、該検出回路や前記制御装置
38等のある電源装置(ボックス)迄引き廻されること
となる所から、上記検出回路を含む近くにある制御回路
に対し誤動作等の雑音障害を生じさせると言う大きな問
題がある丈でなく、検出信号電力が大きく検出回路の回
路素子、例えば、入力側の分圧回路31の抵抗等を大容
量とすると共に、可成り大掛かりな冷却手段を講ずるこ
とが必要になる等の問題があった。However, according to the finishing circuit provided with the discharge state detecting circuit for servo feed control of the conventional example shown in FIG. 7, the discharge gap between the electrode and the workpiece and its surroundings, the high-frequency AC voltage source 30, Even if the stray capacitance of the power supply circuit and the like from the voltage source 30 to the discharge gap can be reduced as desired by devising it, servo control for machining power supply and machining feed is provided in the discharge gap. As a discharge state detecting circuit for use, an electronic circuit in a box of a normal power supply unit from the voltage dividing circuit 31 to the A / D conversion circuit 36 is connected, and not only the electronic circuit but also its circuit configuration and structure are used. However, it has a stray capacitance of approximately 100 to 1000 PF, and the stray capacitance of the detection circuit portion is an obstacle to the finishing process for improving the surface roughness by the high-frequency AC voltage source described above. A. And, in the finishing electric discharge machining using such a high-frequency AC voltage source as a machining power source, as described above, a high voltage of about 1 MHz or more, and a high voltage which is substantially high in machining efficiency as described later, for example, , And a lead wire such as a coaxial cable of a discharge state detection circuit is drawn out of the discharge gap, and a power supply (box) including the detection circuit and the control device 38 is provided. ), There is no major problem that a nearby control circuit including the detection circuit may cause noise interference such as a malfunction, and the detection signal circuit is large. There is a problem that it is necessary to increase the capacity of the element, for example, the resistance of the voltage dividing circuit 31 on the input side, and to take a considerably large cooling means.
【0007】 なお、前記放電間隙、及び該放電間隙廻
りの浮遊容量としては、ワイヤ放電加工のそれは、通常
小さいか、又は容易に小さくできるのに対し、総型等の
電極を使用する所謂ラム型放電加工機の場合は、対向又
は加工面積に応じ浮遊容量が大きくなるだけでなく、電
極又はその支持体を加工ヘッド等に絶縁支持する構造等
によってもかなりの浮遊容量を有することになるが、例
えば、電極を単純形状の小径棒状電極とし、電極と被加
工体間の対向方向及び該方向と直角方向の相対制御移動
により目的とする形状加工を行なうようにするとか、又
は加工液中に金属、合金、炭素、又は硅素等の0.1〜
3.0μmφサイズの粉末を数%前後混入した粉末混入
放電加工として加工中の放電間隙長を広くとるようにし
たり、あるいは放電回路に直列に静電容量を打ち消す線
輪を挿入したり、又該線輪に代えて高透磁性磁気回路
(例えば、特開昭59−42222号公報参照)等も使
用することができるもので、このため本発明の適用は、
ワイヤ放電加工に限らないものである。又、本発明の放
電状態検出信号は、制御装置38の出力38Bとして加
工電源や加工パルスの制御等にも利用できるものであ
る。[0007] Incidentally, before Symbol discharge gap, and as the stray capacitance of the discharge gap around it the wire electric discharge machining, or usually small, or while easily reduced, so-called ram to use electrodes of total type such as In the case of a die-cut electric discharge machine, the stray capacitance not only increases according to the facing or machining area, but also has a considerable stray capacitance due to the structure of insulatingly supporting the electrode or its support on the machining head or the like. For example, for example, the electrode may be a simple-shaped small-diameter rod-shaped electrode, and the target shape processing may be performed by a relative control movement in a direction perpendicular to the opposite direction between the electrode and the workpiece, or in a processing liquid. 0.1 ~ of metal, alloy, carbon or silicon etc.
As the electric discharge machining in which powder having a size of about 3.0 μmφ is mixed by about several percent, the length of the electric discharge gap during machining is widened, or a wire loop for canceling the capacitance is inserted in series with the electric discharge circuit. Instead of a wire loop, a high-permeability magnetic circuit (for example, see JP-A-59-42222) can be used.
It is not limited to wire electric discharge machining. Further, the discharge condition detection signal of the present invention are those which can also be used to control of as an output 38B of the controller 38 processing power and processing pulses.
【0008】 よって本発明は、浮遊容量が少なく、仕
上げ加工の際に適した放電間隙の放電状態検出回路、そ
して、仕上げ加工の際に加工用電源として高電圧の高周
波流電圧源を用いても、該検出回路近傍の各種の制御回
路等に雑音障害を生ぜしめることのない、かつ好適な構
成の該放電状態検出回路を提供すること、及び該検出回
路の検出信号により加工のため各種の制御、例えば特に
サーボ送り制御を行なうことにより、良好なサーボ送り
制御の下に面粗度向上を目的とする高周波交流電圧源に
よる仕上げ加工が確実に行なえるようにした放電加工装
置を提供することにある。Accordingly, the present invention provides a circuit for detecting a discharge state of a discharge gap which has a small stray capacitance and is suitable for finishing, and a high-frequency high-frequency current source as a machining power source for finishing. , detection never give rise to various noise impairments to the control circuit and the like of the circuit near and preferred configuration of the discharge state detection subjecting Hisage the circuit, and the detection circuit detects a signal by a variety for processing To provide an electric discharge machine capable of performing finishing, for example, a high-frequency AC voltage source for the purpose of improving surface roughness under good servo feed control by performing control, for example, servo feed control in particular. It is in.
【0009】[0009]
【課題を解決するための手段】前述の本発明の目的は、
(1)1次及び2次巻線をリングコアに捲回して有する
高周波結合トランスと、前記1次巻線に間歇的に高周波
の電流パルスを供給する電流パルス供給回路とを有し、
前記2次巻線に誘起される高周波交流電圧を加工電極と
被加工体間の放電間隙に供給して仕上げ加工する仕上げ
加工用電圧供給回路を備え、抵抗と発光素子との直列回
路を前記放電間隙に直接並列に接続し、前記発光素子の
発光出力を光一電気信号変換の受光素子により電気信号
に変換して前記放電間隙の放電状態検出信号を得るよう
にした放電状態検出回路を含む別異複数の放電状態検出
回路が前記放電間隙に並列に接続して設けられ、加工に
際して前記高周波交流電圧の仕上げ加工用電圧供給回路
を使用するとき、前記直列回路を有する放電状態検出回
路以外の放電状態検出回路を放電間隙から切り離す機械
的開閉スイッチが、上記直列回路を有する放電状態検出
回路以外の放電状態検出回路と放電間隙との間に設けら
れている放電加工装置とすることにより達成される。前
述の本発明の目的は、(2)加工用電源として、少なく
とも通常加工の電圧パルスを休止時間を置いて間歇的に
供給する加工用電圧パルス供給回路と、高周波交流電圧
を加工電極と被加工体間の放電間隙に供給する仕上げ加
工用電圧供給回路とを備え、放電状態検出回路は、必要
に応じて設けられる開閉スイッチにより、必要に応じて
放電間隙に接離されるものであって、抵抗と発光素子と
の直列回路を前記放電間隙に直接並列に接続し、前記発
光素子の発光出力を光一電気信号変換の受光素子により
電気信号に変換して前記放電間隙の放電状態検出信号を
得るようにした放電状態検出回路と、前記発光素子を含
む放電状態検出回路とは別異の前記放電間隙に並列に接
続される電圧検出回路を有する少なくとも1つの放電状
態検出回路とを有し、得られる放電状態検出信号により
加工送りその他の制御要素を制御する仕上げ加工に際し
て、前記高周波交流電圧供給回路以外の電圧パルス供給
回路、及び上記発光素子を含む放電状態検出回路以外の
放電間隙に接続されている放電状態検出回路を機械的開
閉スイッチにより放電間隙から切り離すように構成して
成る放電加工装置とすることにより達成される。前述の
本発明の目的は、(3)記発光素子と直列な抵抗を、前
記放電間隙に近い位置に設けられる電流制限用の分圧抵
抗と放電間隙から離隔した電源装置の検出回路側に設け
られる第2の分圧抵抗との直列接続体により構成した放
電状態検出回路を有する前記(1)、または(2)に記
載の放電加工装置とすることにより達成される。前述の
本発明の目的は、(4)前記電流制限用の分圧抵抗が、
前記第2の分圧抵抗の分圧値に対して充分大きな分圧値
を負荷する関係の抵抗値に選定され、かつ前記電流制限
用の分圧抵抗が放電間隙に供給される加工液と接触して
冷却されるように加工槽部に配置された構成の放電状態
検出回路を有する前記(3)に記載の放電加工装置とす
ることにより達成される。前述の本発明の目的は、
(5)前記発光素子と並列で逆極性に整流素子を接続し
た放電状態検出回路を有する前記(1)、(2)、
(3)、又は(4)に記載の放電加工装置とすることに
より達成される。前述の本発明の目的は、(6)前記発
光素子が発光ダイオード、前記受光素子がフォトトラン
ジスタ又はフォトダイオードである放電状態検出回路を
有する前記(1)、(2)、(3)、(4)又は(5)
に記載の放電加工装置とすることにより達成される。前
述の本発明の目的は、(7)前記放電状態検出回路の検
出信号を、放電間隙を送りにより制御するサーボ送り制
御装置の放電間隙検出信号とするようにした請求項
(1)、(2)、(3)、(4)、(5)、又は(6)
に記載の放電加工装置とすることにより達成される。SUMMARY OF THE INVENTION The above-mentioned object of the present invention is as follows.
(1) a high-frequency coupling transformer having primary and secondary windings wound around a ring core, and a current pulse supply circuit for intermittently supplying high-frequency current pulses to the primary winding;
A finishing machining voltage supply circuit for supplying a high-frequency AC voltage induced in the secondary winding to a discharge gap between the machining electrode and the workpiece to perform finishing machining; A discharge state detecting circuit connected directly in parallel to the gap, wherein the light emitting output of the light emitting element is converted into an electric signal by a light receiving element for photoelectric conversion to obtain a discharge state detecting signal of the discharge gap; A plurality of discharge state detection circuits are provided in parallel with the discharge gap, and a discharge state other than the discharge state detection circuit having the series circuit is used when a finishing processing voltage supply circuit for the high-frequency AC voltage is used in processing. Electrical discharge machining in which a mechanical open / close switch for disconnecting the detection circuit from the discharge gap is provided between the discharge gap and a discharge state detection circuit other than the discharge state detection circuit having the series circuit. It is achieved by the location. The object of the present invention is to provide (2) a processing voltage pulse supply circuit for intermittently supplying at least a normal processing voltage pulse with a pause time as a processing power source, and a high-frequency AC voltage to a processing electrode and a processing electrode. A voltage supply circuit for finishing machining to supply to the discharge gap between the bodies, wherein the discharge state detection circuit is connected to and separated from the discharge gap as necessary by an on-off switch provided as necessary, A series circuit of a light emitting element and a light emitting element are directly connected in parallel to the discharge gap, and a light emitting output of the light emitting element is converted into an electric signal by a light-to-electric signal conversion light receiving element to obtain a discharge state detection signal of the discharge gap. And at least one discharge state detection circuit having a voltage detection circuit connected in parallel to the discharge gap different from the discharge state detection circuit including the light emitting element. Then, in the finishing process of controlling the machining feed and other control elements by the obtained discharge state detection signal, in the voltage pulse supply circuit other than the high-frequency AC voltage supply circuit, and in the discharge gap other than the discharge state detection circuit including the light emitting element. This is achieved by providing an electric discharge machining apparatus configured to disconnect the connected discharge state detection circuit from the electric discharge gap by a mechanical open / close switch. The object of the present invention is to provide (3) a resistor in series with the light-emitting element, a current-limiting voltage-dividing resistor provided at a position close to the discharge gap, and a detection circuit side of a power supply device separated from the discharge gap. This is achieved by the electric discharge machining apparatus according to the above (1) or (2), which has a discharge state detection circuit formed by a series connection with a second voltage dividing resistor. The object of the present invention is as described above. (4) The voltage-dividing resistor for limiting the current is:
The resistance value is selected so that a sufficiently large partial pressure value is applied to the divided voltage value of the second voltage-dividing resistor, and the current-limiting voltage-dividing resistor is brought into contact with a machining fluid supplied to a discharge gap. This is achieved by the electric discharge machining apparatus according to (3), further including a discharge state detection circuit configured to be disposed in the machining tank so as to be cooled. The object of the invention described above is
(5) The above (1), (2), which has a discharge state detection circuit in which a rectifying element is connected in reverse polarity in parallel with the light emitting element.
This is achieved by using the electric discharge machine described in (3) or (4). The object of the present invention described above is to provide (6) a discharge state detecting circuit in which the light emitting element is a light emitting diode and the light receiving element is a phototransistor or a photodiode. ) Or (5)
This is achieved by the electric discharge machining device described in (1). The object of the present invention is that the detection signal of the discharge state detection circuit is a discharge gap detection signal of a servo feed control device that controls a discharge gap by feeding. ), (3), (4), (5), or (6)
This is achieved by the electric discharge machining device described in (1).
【0010】[0010]
【作用】本発明の放電加工装置は、上述のような構成で
あるから、放電間隙に接続されている放電状態検出回路
は、抵抗とフォトカプラの発光素子とを直列に接続した
直列回路部分のみで、前記フォトカプラの以後の積分回
路や増幅回路あるいはさらにサンプルホールド増幅回路
やA/D変換器等は前記フォトカプラにより放電間隙か
ら絶縁されており、又この検出回路とは、必要に応じて
別異に設けられている他の放電間隙の放電状態検出回路
は、機械的開閉スイッチにより切り離されるので放電間
隙に対して設けられる放電状態検出回路による浮遊容量
を最小の状態とすることができ、更に、該検出回路入力
の放電間隙に近い側の分圧抵抗は検出回路の浮遊容量に
よる放電を抑制する高抵抗と言う構成であるから仕上げ
加工を好適にサーボ制御をした状態で、加工面が荒れな
く所定の微細面粗度に、かつ効率良い加工ができるよう
になった。又、上記のように、仕上げ加工の際に加工用
電源として、雑音障害の大きな高電圧の高周波交流電圧
を安全、確実に用いることを可能とした高効率の放電加
工装置を構成することができる。Since the electric discharge machining apparatus of the present invention has the above-described configuration, the electric discharge state detecting circuit connected to the electric discharge gap is only a series circuit portion in which a resistor and a light emitting element of a photocoupler are connected in series. An integrating circuit and an amplifying circuit subsequent to the photocoupler, or further a sample-and-hold amplifying circuit and an A / D converter, are insulated from a discharge gap by the photocoupler. Since the discharge state detection circuit of another discharge gap provided separately is separated by a mechanical open / close switch, the stray capacitance by the discharge state detection circuit provided for the discharge gap can be minimized, Furthermore, since the voltage-dividing resistor on the side near the discharge gap at the input of the detection circuit is a high resistance that suppresses the discharge due to the stray capacitance of the detection circuit, it is preferable to perform finishing processing. While a control, machined surface in a predetermined fine surface roughness rather rough, and has enabled efficient processing. Further, as described above, it is possible to configure a high-efficiency electric discharge machine capable of safely and reliably using a high-frequency AC voltage having a large noise disturbance as a machining power supply at the time of finishing machining. .
【0011】[0011]
【実施例】図1は、本発明実施例の放電間隙の放電状態
検出回路41〜47を、前記従来例の図7の放電状態検
出回路31〜37と並列に、放電間隙に機械的開閉スイ
ッチ48により切換え接続可能に設けると共に仕上げ加
工用の高周波交流電圧源30と、荒加工、中加工、中仕
上げ加工用等の通常型の間歇的な電圧パルス源5とを機
械的開閉スイッチ49により切換え接続可能に設けた一
実施例を示すものである。FIG. 1 shows a discharge gap detecting circuit 41-47 according to an embodiment of the present invention in parallel with a discharge gap detecting circuit 31-37 of FIG. A mechanical open / close switch 49 switches between a high-frequency AC voltage source 30 for finishing and a normal intermittent voltage pulse source 5 for roughing, medium machining, medium finishing, etc. 1 shows an embodiment provided so as to be connectable.
【0012】図は、機械的開閉スイッチ48及び49の
切換えにより、電極1、被加工体3間の放電間隙には、
仕上げ加工用電源として高周波交流電圧源30が、又放
電状態検出回路として本発明の一実施例回路が接続され
ている状態を示すもので、41は各種発光ダイオード等
の発光素子41Aと、各種光導電素子やフォトダイオー
ド、又はフォトトランジスタ等の受光素子41Bとから
なるフォトセンサ、フォトカプラ、又は光電変換素子
で、発光素子41Aと受光素子41Bとは電気的に絶縁
されており、上記発光素子41Aは無誘導抵抗等の抵抗
41Cと直列に接続して放電間隙に直接、勿論リード線
等を介してであるが、並列に接続される。43Aはフォ
トカプラ41出力の積分回路、42は反転増幅回路、4
4は更に反転増幅して、可変抵抗44Aの調整によりサ
ーボゲインが調整される利得調整回路、43Bは積分回
路、45はサンプルホールド増幅回路、46はA/D変
換器、又47は入出力回路で、前記回路43Aから回路
47の間は前述した従来の検出回路32〜37部分と構
成上微差があるが、実質上同一のもので、その検出調整
されたデジタル信号はNC制御装置等を有する制御装置
38に入力して、入力手段38Aの入力信号等と所定演
算等処理され、サーボモータ40のドライバ39にドラ
イブ制御信号を出力する外、必要に応じ、例えば加工用
電源やパルスの条件、又は加工液供給装置の供給条件等
の加工条件を検出信号に応じて制御する制御信号38B
を出力する。FIG. 2 shows that the mechanical opening / closing switches 48 and 49 are switched so that a discharge gap between the electrode 1 and the workpiece 3 is formed.
A high-frequency AC voltage source 30 is connected as a finishing power supply, and a circuit according to one embodiment of the present invention is connected as a discharge state detecting circuit. Reference numeral 41 denotes a light-emitting element 41A such as various light-emitting diodes and various light-emitting elements. A light sensor, a photocoupler, or a photoelectric conversion element including a light receiving element 41B such as a conductive element, a photodiode, or a phototransistor. The light emitting element 41A and the light receiving element 41B are electrically insulated. Is connected in series with a resistor 41C such as a non-inductive resistor and connected directly to the discharge gap, of course, via a lead wire or the like, but in parallel. 43A is an integrating circuit of the output of the photocoupler 41, 42 is an inverting amplifier circuit,
4 is a gain adjustment circuit for further inverting and amplifying and adjusting the servo gain by adjusting the variable resistor 44A, 43B is an integration circuit, 45 is a sample and hold amplifier circuit, 46 is an A / D converter, and 47 is an input / output circuit. Although there is a slight difference in configuration between the circuits 43A to 47 and the above-described conventional detection circuits 32 to 37, they are substantially the same, and the digital signals detected and adjusted are controlled by an NC control device or the like. Input to the control device 38 having a predetermined operation such as an input signal of the input means 38A, and outputs a drive control signal to the driver 39 of the servomotor 40. Or a control signal 38B for controlling a processing condition such as a supply condition of a processing liquid supply device according to a detection signal.
Is output.
【0013】なお、図に於て発光素子41Aに並列に接
続された素子41Dは整流素子であって、発光素子41
Aが発光ダイオードの場合に同様な発光ダイオードであ
っても良く、発光素子41Aの逆電圧に対する耐圧保護
のためと、加工用電源として高周波交流電圧源を用いた
場合に、該発光ダイオード41A部に於ける正負の電圧
降下を同一にして発光特性を良好に保つためである。In the drawing, an element 41D connected in parallel to the light emitting element 41A is a rectifying element,
When A is a light-emitting diode, a similar light-emitting diode may be used. In order to protect the light-emitting element 41A against withstand voltage against reverse voltage and to use a high-frequency AC voltage source as a processing power supply, This is for keeping the positive and negative voltage drops the same and keeping the emission characteristics good.
【0014】以上の構成によれば、仕上げ加工に際して
は、電極1と被加工体3とからなる放電間隙には、仕上
げ加工用電源としての高周波交流電圧源30のみが接続
されているだけで、仕上げ加工工程以前の中仕上げ加工
等の段階まで使用された、通常形の電子スイッチ素子の
制御オン・オフにより休止時間を置いて間歇的に電圧パ
ルスを供給する電圧パルス源5は、機械的開閉スイッチ
49により放電間隙から完全に切り離され、又通常1個
以上複数個が設けられるであろう放電状態検出回路も機
械的開閉スイッチ48により本発明の放電状態検出回路
のみが接続されているだけで、放電間隙には抵抗41C
と発光素子41Aとの直列回路のみが並列接続されてい
る訳であるから、放電間隙廻り、又少なくとも放電間隙
廻り回路網による浮遊静電容量は最も少ない状態にある
わけで、放電間隙廻り回路網による浮遊静電容量による
高いピーク電流値のある放電や1放電当たりの放電エネ
ルギが所定値よりも大きくなると言うことは無く、した
がって加工面が荒れたりすることはなく、又逆に前記浮
遊容量が存在して、前記高周波交流電圧や仕上げ加工パ
ルス等が不測に減衰等されて加工効率を低下させると言
うこともなく、他方前記浮遊容量を増加させること無く
放電状態が検出できて、当該仕上げ加工の送りを好適
に、又は所望に制御して加工することができるから、被
加工体3加工面の太鼓特性や前加工段階までによる加工
形状のバラツキ等を所望に制御しつつ加工することがで
き、所望とする約3.5〜1μmRmaxの加工面粗度
出し仕上げ加工を迅速、確実にすることができることに
なる。According to the above construction, only the high-frequency AC voltage source 30 as a power source for finishing is connected to the discharge gap formed by the electrode 1 and the workpiece 3 during finishing. A voltage pulse source 5 for intermittently supplying a voltage pulse with an idle time by controlling on / off of a normal type electronic switch element used up to a stage such as a semi-finishing process before the finishing process is mechanically opened and closed. The discharge state detecting circuit which is completely separated from the discharge gap by the switch 49, and which is usually provided with one or more units, is only connected to the discharge state detecting circuit of the present invention by the mechanical open / close switch 48. , Discharge gap 41C
Since only the series circuit of the discharge gap and the light emitting element 41A are connected in parallel, the floating capacitance around the discharge gap and at least the floating capacitance due to the circuit around the discharge gap is in the minimum state. The discharge with a high peak current value due to the stray capacitance and the discharge energy per discharge are not greater than a predetermined value, so that the machined surface is not roughened. Existence does not mean that the high-frequency AC voltage or the finishing pulse is unexpectedly attenuated or the like to lower the machining efficiency, and on the other hand, the discharge state can be detected without increasing the stray capacitance, and the finishing process is performed. Can be processed by controlling the feeding of the workpiece 3 suitably or as desired, so that the drum characteristics of the processing surface of the workpiece 3 and the variation of the processing shape due to the pre-processing stage can be reduced. Can be processed while controlling the Nozomu, quickly processed surface roughness out finishing about 3.5~1μmRmax to desired, it will be able to ensure.
【0015】即ち、前述の図7の加工回路の場合、放電
状態検出回路31〜37の浮遊容量の存在により、加工
効率が悪いだけでなく、加工面粗度を3.5〜1μmR
max、又はそれ以上の面粗度仕上げができず、このた
め従来約3.5〜1μmRmax、又はそれ以上の面粗
度仕上げのためには、放電状態検出回路31〜37を機
械的スイッチ等により放電間隙から切り離し、制御装置
38のNC装置に設定した或一定速度で加工するように
していたものであるが、かかるサーボ制御でない一定速
度の加工送りの加工では、被加工体3加工面の太鼓特性
や形状のバラツキ等を所望に制御する加工とすることが
できず不具合であったものである。That is, in the case of the machining circuit shown in FIG. 7, the presence of the stray capacitance of the discharge state detection circuits 31 to 37 causes not only poor machining efficiency but also a machining surface roughness of 3.5 to 1 μmR.
Max or higher surface roughness finish cannot be performed. Therefore, conventionally, for surface roughness finish of approximately 3.5 to 1 μm Rmax or higher, the discharge state detection circuits 31 to 37 are controlled by a mechanical switch or the like. The workpiece is cut off from the discharge gap, and is processed at a certain constant speed set in the NC device of the control device 38. However, in such processing of processing feed at a constant speed other than the servo control, a drum on the processing surface of the workpiece 3 is not used. This was a problem because it was not possible to perform processing for controlling the variation in characteristics and shapes as desired.
【0016】而して、加工用電源を開閉スイッチ49に
よる切換えにより間歇的な電圧パルス源5に切換えて、
荒加工とか中加工等をしようとする場合、前記電圧パル
ス源5の電源形式等にもよるが、その場合は図示のごと
く放電状態検出回路を開閉スイッチ48により従来の検
出回路31〜37に切り替える場合の外、本発明の放電
状態検出回路41〜47をそのまま使用するとか、或い
は又該回路41〜47が荒加工等の加工に障害となるこ
とはないから、該回路41〜47はそのまま接続した状
態としておいて、従来の検出回路31〜37を稼働させ
る接続構成としても良い。Thus, the power supply for processing is switched to the intermittent voltage pulse source 5 by switching by the open / close switch 49,
When rough machining or medium machining is to be performed, the discharge state detection circuit is switched to the conventional detection circuits 31 to 37 by the open / close switch 48 as shown in FIG. In other cases, the discharge state detection circuits 41 to 47 of the present invention are used as they are, or the circuits 41 to 47 do not hinder the processing such as roughing. In this state, a connection configuration for operating the conventional detection circuits 31 to 37 may be adopted.
【0017】図2は、前述した図1における放電加工を
ワイヤ放電加工の場合として、又前記間歇的な電圧パル
ス源5と高周波交流電圧源30の具体例を示したもの
で、1は一対の間隔を置いて配置した位置決めガイド2
A、2B間を所定の張力を付与した状態で軸方向に更新
送り移動させられるワイヤ電極、3は図示しないxyク
ロステーブルに載置したワークスタンド4に取り付けら
れ、ワイヤ電極軸方向と略直角方向から微小放電間隙を
介して相対向せしめられる被加工体で、図示しない加工
液供給手段による加工液供給介在の下に両者間に印加さ
れる間歇的な電圧パルス等の加工電圧により放電を生ぜ
しめて加工が行なわれるものである。そして、荒加工と
寸法形状精度出しの少なくともセカンドカット迄の第1
の加工工程の加工のための加工電圧、即ち、間歇的な電
圧パルスは、図示した一実施例のワイヤ放電加工用電圧
パルス源5から、給電接続線11A、11Bとしては、
浮遊インダクタンス成分の小さい同軸又はシールド線を
介し、或いは更に、放電間隙近傍の引き回しリード線に
は、好ましくは浮遊キャパシタンス成分の小さい縒線を
利用するが如くにしてワイヤ電極1と被加工体3間に供
給印加される。FIG. 2 shows a specific example of the intermittent voltage pulse source 5 and the high-frequency AC voltage source 30 in which the electric discharge machining in FIG. 1 is wire electric discharge machining. Positioning guide 2 spaced apart
A wire electrode, which is reciprocated and moved in the axial direction while applying a predetermined tension between A and 2B, 3 is attached to a work stand 4 mounted on an xy cross table (not shown), and is substantially perpendicular to the axial direction of the wire electrode. The workpieces are opposed to each other via a minute discharge gap, and a discharge is generated by a machining voltage such as an intermittent voltage pulse applied between the two under the machining fluid supply by a machining fluid supply unit (not shown). Processing is performed. Then, the first process up to at least the second cut of roughing and dimensional accuracy
The processing voltage for the processing of the processing step, that is, the intermittent voltage pulse is supplied from the voltage pulse source 5 for wire electric discharge machining in the illustrated embodiment as the power supply connection lines 11A and 11B.
Preferably, a stranded wire having a small floating capacitance component is used for a lead wire near the discharge gap via a coaxial or shielded wire having a small floating inductance component. Is applied to
【0018】前記電圧パルス源5は、直流電圧源6Aと
電流容量に応じ複数個が並列に接続されるMOS−FE
Tトランジスタ等の電子スイッチ素子6Bと電流制限抵
抗6C及び逆電圧防止整流器6Dとの直列回路からな
る、従来最も通常の間歇的な電圧パルスの生成供給回路
6が、放電間隙に並列となるように給電接続線11A、
11Bに接続され、前記間歇的な電圧パルスはパルス制
御装置7によるスイッチ素子6Bの制御により所望に生
成される。即ち、制御装置7の前記スイッチ素子6Bの
制御装置部分としては、スイッチ素子6Bを放電間隙の
放電状態検出信号により変更制御をする場合を除き、予
め選択設定した一定のオン時間信号τONとオフ時間信
号τOFFとを規則的に交互に繰り返して電圧パルスを
供給制御する場合と、スイッチ素子6Bのオン時間信号
を放電間隙に電圧パルスの印加開始時より放電間隙で放
電が開始するまでの該放電開始遅延期間の関数とし増大
する、即ち各放電パルスの放電持続時間を設定の一定値
とするよう電圧パルス印加開始後放電間隙での放電開始
時より前記オン時間信号の計測を開始し、計測完了によ
りスイッチ素子6Bをオフとしてオフ時間に移行させる
制御をするもの等があり、以下の説明では、主として前
記後者の場合について説明を加えるが、本発明は何等こ
れに限定されるものではない。A plurality of voltage pulse sources 5 are connected to the DC voltage source 6A in accordance with the current capacity.
The most usual conventional intermittent voltage pulse generation / supply circuit 6 comprising a series circuit of an electronic switch element 6B such as a T transistor, a current limiting resistor 6C, and a reverse voltage prevention rectifier 6D is arranged in parallel with the discharge gap. Power supply connection line 11A,
11B, the intermittent voltage pulse is generated as desired by the control of the switch element 6B by the pulse control device 7. That is, the control device portion of the switch device 6B of the control device 7 includes a predetermined ON time signal τ ON and OFF which is selected and set in advance, except when the switch device 6B is changed and controlled by the discharge state detection signal of the discharge gap. The time signal τ OFF is regularly and alternately repeated to control the supply of the voltage pulse, and the ON time signal of the switching element 6B is applied to the discharge gap from the start of application of the voltage pulse to the start of discharge in the discharge gap. The measurement of the on-time signal is started from the start of the discharge in the discharge gap after the start of the application of the voltage pulse so that the discharge duration increases as a function of the discharge start delay period, that is, the discharge duration of each discharge pulse is set to a fixed value, and the measurement There is a control for turning off the switch element 6B upon completion and shifting to the off time. In the following description, mainly the latter case will be described. Obtain, but the present invention is not construed as being limited thereto.
【0019】前記電圧パルス源5には、前記スイッチ素
子6Bのオン・オフによる加工電圧パルス供給回路6に
加えて、該回路6による放電パルスの放電電流振幅Ip
を増大し、延ては加工平均電流を増大させて、加工速度
を一段と増加させるためのパルス電流増幅回路または電
流パルス供給回路8が、可変直流電圧源8Aとスイッチ
素子8Bと逆電圧防止整流器8Cとから成る直列回路と
して回路6と並列に設けられている。この電流パルス供
給回路8は制御装置7によるスイッチ素子8Bのオン時
に急峻な立ち上がりの高電流を出力するように、所謂電
流制限抵抗がその直列回路中にない無抵抗回路、乃至は
スイッチ素子8Bの破損防止のために制御装置7に設け
られているスイッチ素子8Bの電流制御器7Aの作動の
ための微小な検出抵抗の他には電流制限抵抗が挿入され
てない回路8であって、スイッチ素子6Bのオン時間信
号又は前記放電開始よりのオン時間信号は、ワイヤ放電
加工に於いては、大きくても数10μS以内、通常数μ
S以内であるから、スイッチ素子8Bを回路6による印
加電圧パルスにより間隙での放電開始を検出して作動す
るオン時間信号の間オンさせるようにしても、スイッチ
素子8B又は、少なくとも回路8の電流飽和領域動作へ
の移行時間等の関係から該回路8に電流制限抵抗が設け
られていなくても破損を免れ得る場合があるが、上記ス
イッチ素子8Bの動作領域を不飽和領域と又は、少なく
とも回路8の電流がスイッチ素子8Bの飽和電流値より
も充分小さい(通常数分の一)範囲が動作領域となるよ
うに条件設定すれば、該スイッチ素子8Bの破損の問題
はなく、かつ該スイッチ素子8B乃至は回路8の電流オ
フ切れ特性が鋭く、急峻となるから好ましいものであ
る。The voltage pulse source 5 includes, in addition to a machining voltage pulse supply circuit 6 for turning on and off the switch element 6B, a discharge current amplitude Ip of a discharge pulse from the circuit 6.
And a pulse current amplification circuit or current pulse supply circuit 8 for further increasing the processing speed by increasing the processing average current, comprises a variable DC voltage source 8A, a switch element 8B, and a reverse voltage prevention rectifier 8C. And is provided in parallel with the circuit 6. The current pulse supply circuit 8 outputs a steep rising high current when the control device 7 turns on the switch element 8B so that a so-called resistance-free circuit having no so-called current limiting resistor in the series circuit or the switch element 8B. A circuit 8 in which a current limiting resistor is not inserted in addition to a minute detection resistor for operating a current controller 7A of a switch element 8B provided in a control device 7 for preventing damage, In the wire electric discharge machining, the on-time signal of 6B or the on-time signal from the start of the discharge is within several tens μS at most, and usually several μS.
Since it is within S, even if the switch element 8B is turned on during the on-time signal that operates by detecting the start of discharge in the gap by the voltage pulse applied by the circuit 6, the switch element 8B or at least the current of the circuit 8 Although there is a case where the circuit 8 can be prevented from being damaged even if the current limiting resistor is not provided in the circuit 8 due to the transition time to the operation in the saturation region, etc., the operation region of the switch element 8B is referred to as an unsaturated region or at least a circuit region. If the condition is set such that the range in which the current 8 is sufficiently smaller than the saturation current value of the switch element 8B (usually a fraction) is the operation region, there is no problem of breakage of the switch element 8B, and the switch element 8B is not damaged. This is preferable because the current-off characteristic of the circuit 8B or 8B becomes sharp and steep.
【0020】前述の電流パルス供給回路8は、電圧パル
ス供給回路6と共に電圧パルス源5として、被加工体3
に最初に加工溝を形成する荒加工、即ちファーストカッ
ト加工工程と、該ファーストカット加工工程後の加工の
寸法・形状精度出し加工を行なうセカンドカット加工工
程、即ち加工電圧として間歇的な電圧パルスを用いる前
述第1の加工工程に用いられるもので、ゲート入力は切
換えスイッチ8Eにより制御装置7に接続されていて、
例えば前述のような回路6との関連制御が行われるもの
であるが、前記第1の加工工程であるセカンドカット加
工工程の加工の終了後、第2の加工工程である高周波交
流電圧を用いる加工面粗度出し加工の1乃至2の仕上げ
加工工程(例えば、サードカット加工工程、或いは更に
フォースカット加工工程)に移行するに際し、電圧パル
ス供給回路6を必要に応じ開閉スイッチ49で切り離す
と共に、前記切換えスイッチ8Eを高周波の間歇パルス
のゲート信号回路8D側に切換えて、電流パルス供給回
路8を高周波電流パルス発生回路10として機能せしめ
るものである。The above-described current pulse supply circuit 8 serves as the voltage pulse source 5 together with the voltage pulse supply circuit 6 as the workpiece 3
First, rough processing for forming a processing groove, that is, a first cut processing step, and a second cut processing step for performing processing for obtaining the size and shape accuracy of processing after the first cut processing step, that is, an intermittent voltage pulse as a processing voltage The gate input is connected to the control device 7 by a changeover switch 8E, and is used in the first processing step used.
For example, the control related to the circuit 6 as described above is performed. After the completion of the second cut processing as the first processing, the processing using the high-frequency AC voltage as the second processing is performed. When shifting to one or two finishing processing steps (for example, a third cutting processing step or a further force cutting processing step) of the surface roughness processing, the voltage pulse supply circuit 6 is cut off by an open / close switch 49 as necessary, and The changeover switch 8E is switched to the high-frequency intermittent pulse gate signal circuit 8D side so that the current pulse supply circuit 8 functions as the high-frequency current pulse generation circuit 10.
【0021】そして、その際、放電状態検出回路は、開
閉スイッチ48により回路31〜37から回路41〜4
7へ切換えられ、又前記高周波電流パルス発生回路10
と、放電間隙間に設けられた高周波結合トランス13と
前記寸法・形状精度出しの第1の加工工程から加工面粗
度等の仕上げの第2の加工工程に移行する際の回路切換
え開閉スイッチ14とから成る函体状のボックスに収納
された回路装置12とにより構成される高周波交流電圧
源30は、以下の如き構成、及び切換え使用されるもの
である。At this time, the discharge state detecting circuit is controlled by the open / close switch 48 from the circuits 31 to 37 to the circuits 41 to 4
7 and the high-frequency current pulse generation circuit 10
And a high-frequency coupling transformer 13 provided between the discharge gaps and a circuit switching open / close switch 14 for shifting from the first processing step for obtaining the dimensional and shape accuracy to the second processing step for finishing the processing surface roughness and the like. The high-frequency AC voltage source 30 constituted by the circuit device 12 housed in a box-shaped box having the following configuration and switching is used as follows.
【0022】高周波結合トランス13は、前記高周波電
流パルス発生回路10が出力する間歇的な高周波電流パ
ルス1個1個を1サイクルの高周波交流電圧に変換する
もので、高周波用フェライト等から成る高透磁率のリン
グコア13Aに1次巻線13Bと2次巻線13Cとが、
巻線比が1:1〜3、好ましくは1:1〜2、捲回数が
1次巻線1〜5ターン、好ましくは1〜2ターン、2次
巻線1〜12ターン、好ましくは1〜4ターンの如く、
高周波数応答可能に何れも少ない巻数で、かつどちらか
と言えば電圧が高くて電流が小さい仕上げ加工用の高周
波交流電圧を得る目的から、1次巻線よりも2次巻線の
捲回数が同一以上となるように捲回してあるものであ
る。The high-frequency coupling transformer 13 converts each intermittent high-frequency current pulse output from the high-frequency current pulse generating circuit 10 into a one-cycle high-frequency AC voltage. A primary winding 13B and a secondary winding 13C are provided on a ring core 13A of magnetic susceptibility.
The winding ratio is 1: 1 to 3, preferably 1: 1 to 2, and the number of turns is 1 to 5 turns of the primary winding, preferably 1 to 2 turns, 1 to 12 turns of the secondary winding, preferably 1 to 1 turn. Like four turns,
In order to obtain a high frequency AC voltage for finishing processing, which has a small number of turns for each high frequency response and is rather high and has a small current, the number of turns of the secondary winding is equal to that of the primary winding. It is wound so as to be as described above.
【0023】次に、前記高周波電流パルス発生回路10
の出力と、前記ワイヤ電極1・被加工体3から成る放電
間隙間の給電接続線11A、11Bと前記回路装置12
の接続と切換え構成に付き説明すると、1次巻線13B
を高周波電流パルス発生回路10の出力と接離する開閉
スイッチと2次巻線13Cを放電間隙と接離する開閉ス
イッチとは、前記高周波電流パルス発生回路10の出力
両端と放電間隙のワイヤ電極1と被加工体3夫々の間に
接続される給電接続線11A、11Bの回路部分に設け
られる給電回路開閉スイッチ14A、14Bと、1次巻
線の入力両端を前記給電回路開閉スイッチ14A、14
Bよりも高周波電流パルス発生回路10側でその出力線
の両方に接続する間の一方又は両方の接続回路に挿設し
た1次巻線開閉スイッチ14Cと、及び2次巻線の出力
両端を前記給電回路開閉スイッチ14A、14Bよりも
放電間隙側でワイヤ電極1と被加工体3の両方に接続す
る間の一方又は両方の接続回路に挿設した2次巻線開閉
スイッチ14Dとから成り、前記2つの給電回路開閉ス
イッチ14A、14Bと、1次巻線及び2次巻線開閉ス
イッチ14C、14Dとは、前者の開閉スイッチ14
A、14Bがオンのとき、後者の開閉スイッチ14C、
14Dがオフとなるように互いに逆に開閉せしめられる
ことによりその目的を達成するものであり、前記給電回
路開閉スイッチ14A、14Bがオフで、1次及び2次
巻線開閉スイッチ14C、14Dがオンのとき、本発明
の目的とする第2の加工工程で使用する高周波交流電圧
による仕上げ加工用電源回路が構成されることになる。
なお、、図示では1次巻線及び2次巻線の各開閉スイッ
チとして、夫々各1個が設けられた場合で、かつ設けら
れる切換えスイッチの数を最も少ない数として構成した
場合であるが、スイッチの数により種々の切換え回路構
成と為し得ることは当然である。Next, the high-frequency current pulse generation circuit 10
And the power supply connection lines 11A and 11B between the discharge gaps composed of the wire electrode 1 and the workpiece 3 and the circuit device 12
The connection and switching configuration of the primary winding 13B will be described.
The open / close switch for connecting / disconnecting the secondary winding 13C to / from the discharge gap and the open / close switch for connecting / disconnecting the secondary winding 13C to / from the output of the high-frequency current pulse generation circuit 10 are connected to both ends of the output of the high-frequency current pulse generation circuit 10 and the wire electrodes 1 Power supply circuit open / close switches 14A, 14B provided in the circuit portions of the power supply connection lines 11A, 11B connected between the power supply connection lines 11A, 11B and the power supply circuit open / close switches 14A, 14 respectively.
The primary winding on / off switch 14C inserted in one or both of the connection circuits during connection to both of the output lines on the high frequency current pulse generation circuit 10 side from B, and the both ends of the output of the secondary winding are A secondary winding on / off switch 14D inserted in one or both connection circuits during connection to both the wire electrode 1 and the workpiece 3 on the discharge gap side of the power supply circuit on / off switches 14A and 14B; The two power supply circuit on / off switches 14A and 14B and the primary and secondary winding on / off switches 14C and 14D are the former on / off switch 14.
When A and 14B are on, the latter on / off switch 14C,
This object is achieved by opening and closing the power supply circuit on / off switches 14A and 14B off and turning on the primary and secondary winding on / off switches 14C and 14D. At this time, a power supply circuit for finishing processing by a high-frequency AC voltage used in the second processing step which is the object of the present invention is configured.
It should be noted that the drawing shows a case in which one open / close switch is provided for each of the primary winding and the secondary winding, and a case where the number of changeover switches provided is the smallest. It goes without saying that various switching circuit configurations can be achieved depending on the number of switches.
【0024】図3は、図2の加工電源回路を前述第2の
加工工程の仕上げ加工用電源回路として、即ち、開閉ス
イッチ49をオフ、切換えスイッチ8Eによりゲート信
号回路8Dをオンにして高周波電流パルス発生回路10
を機能させ、給電回路開閉スイッチ14A、14Bをオ
フ、トランス1次及び2次巻線開閉スイッチ14C、1
4Dを夫々オンとして作動させた場合のタイミングチャ
ートを2サイクル分、ほぼ理想的な波形として示したも
ので、aは前記間歇パルスのゲート信号回路8Dから出
力してスイッチ素子8Bをオン・オフさせる高周波のゲ
ート信号、bは前記ゲート信号に基づき高周波電流パル
ス発生回路10が出力し、トランス13の1次巻線13
Bに供給する電流パルス、cは前記パルス電流に基づき
2次巻線13Cに誘起され放電間隙に印加される高周波
交流電圧と該高周波交流電圧印加に基づき放電間隙で放
電が発生した場合の放電間隙電圧波形、dは同放電間隙
の放電電流の例である。そしてこのような電流パルス発
生回路10と結合トランス13との組合わせによる発生
高周波交流電圧の波形成形(通常、急峻で滑らかな正弦
波状化、または更にATOFF=0の連続波化等)に
は、2次巻線13Cと放電間隙の放電回路に直列に所望
のインダクタンスを挿入することが有効で、そのための
手法としては、所定のインダクタンスを有するコイルを
直列に接続するとか、電極1又はガイド2A,2B部に
於いてワイヤ電極1を囲繞するように高透磁率の磁気コ
アを設けるようにしても良い。FIG. 3 shows the processing power supply circuit of FIG. 2 as a power supply circuit for finishing processing in the second processing step, that is, the open / close switch 49 is turned off, the gate signal circuit 8D is turned on by the changeover switch 8E, and the high-frequency current Pulse generation circuit 10
Function, the power supply circuit on / off switches 14A, 14B are turned off, the transformer primary and secondary winding on / off switches 14C, 1C,
The timing chart in the case where each of the 4Ds is turned on is shown as an almost ideal waveform for two cycles, and “a” is output from the intermittent pulse gate signal circuit 8D to turn on / off the switch element 8B. The high-frequency gate signal b is output from the high-frequency current pulse generation circuit 10 based on the gate signal, and the primary winding 13
The current pulse supplied to B, c is a high-frequency AC voltage induced in the secondary winding 13C based on the pulse current and applied to the discharge gap, and a discharge gap when a discharge occurs in the discharge gap based on the application of the high-frequency AC voltage. The voltage waveform d is an example of the discharge current in the discharge gap. The waveform shaping of the generated high-frequency AC voltage by combining the current pulse generating circuit 10 and the coupling transformer 13 (usually, a steep and smooth sinusoidal waveform, or a continuous waveform of AT OFF = 0) is performed. It is effective to insert a desired inductance in series into the secondary winding 13C and the discharge circuit in the discharge gap. For this purpose, a coil having a predetermined inductance is connected in series, or the electrode 1 or the guide 2A is connected. , 2B, a magnetic core having a high magnetic permeability may be provided so as to surround the wire electrode 1.
【0025】前記ゲート信号回路8Dから出力する間歇
的なパルスのゲート信号は、本発明が適用される仕上げ
加工に於いては、図示ではTON=100nS、T
OFF=1.0μSで、大凡約TON=50nS〜10
00nS程度のμSオーダ以下で、TOFF=500n
S〜10μs又は数10μS程度であり、Cの交流電圧
が相互に繋がるのを限度として、好ましくはATOFF
≧0となるよう条件設定をするものである。又、前記高
周波電流パルス発生回路10の出力電流パルス波形b
は、スイッチ素子8Bが、又は少なくとも回路8の電流
がスイッチ素子8Bの飽和電流値よりも充分小さい立上
がり電流の飽和領域作動状態となる前にゲート信号aが
オフとなり、スイッチ素子8B、又は回路8の電流切れ
が高速で行われたものとして示されている。In the finishing processing to which the present invention is applied, the gate signal of the intermittent pulse output from the gate signal circuit 8D is T ON = 100 nS, T
OFF = 1.0 μS, approximately T ON = 50 nS-10
T OFF = 500n at μS order or less of about 00nS
S is about 10 μs or several tens of μs, and it is preferable to use AT OFF as long as the AC voltages of C are mutually connected.
The condition is set so that ≧ 0. The output current pulse waveform b of the high-frequency current pulse generation circuit 10
Is that the gate signal a is turned off before the switch element 8B or at least the current in the circuit 8 enters the saturation region operation state of the rising current sufficiently smaller than the saturation current value of the switch element 8B, and the switch element 8B or the circuit 8 Is shown as having occurred at a high speed.
【0026】 又、前記図2の2次巻線13Cの高周波
交流電圧は、近時のテストに依れば、外径約55mm
φ、内径約30mmφの、高透磁率Mn−Znフェライ
トや、Ni−Znフェライト等のフェライトトロイダル
コア(例えば、TDK製PC50[又はPC30]T4
0×16×24)を2重積したコア13Aに、断面約
3.5mm2のテフロン系樹脂被覆導線を1次巻線13
B:1ターン、2次巻線13C:2ターンとしたとき、
直流電圧源8Aの出力約60Vで正負に夫々約150〜
170V、電圧源8Aの出力約25Vで正負に夫々約6
0〜65Vで、前述第2の加工工程である加工面粗度改
善の仕上げ加工(サードカット、及びフォースカット)
に適用可能な、好適に高電圧の高周波交流電圧が得ら
れ、放電電流波形dに示す如く、交流電圧1サイクルの
初めの半波で放電が発生すると、次の逆極性の半波に於
いては続いて放電が起こることになるが、平均加工電流
が1A前後程度より小さい値で仕上げ加工を進行させる
ことができる。例えば、前記正負約150〜170V、
約1MHzの高周波交流電圧で、第1の加工工程のセカ
ンドカット加工迄で約10〜13μmRmaxに仕上げ
た加工面を、第2の加工工程のサードカットで加工する
ことにより、約3.5μmRmax程度又はそれ以上に
仕上げることができ、更に前記正負約60Vの高周波交
流電圧でフォースカット加工することにより約1.5μ
mRmax程度に仕上がるものである。[0026] In addition, high-frequency AC voltage of the secondary winding 13C of the previous Symbol Figure 2, according to a recent test, an outer diameter of about 55mm
φ, inner diameter of about 30 mmφ, ferrite toroidal core such as high permeability Mn-Zn ferrite or Ni-Zn ferrite (for example, TDK PC50 [or PC30] T4
0 × 16 × 24), a Teflon-based resin-coated conductive wire having a cross section of about 3.5 mm 2
B: 1 turn, secondary winding 13C: 2 turns,
The output of the DC voltage source 8A is about 60V and the output is about 150-
170 V, the output of the voltage source 8A is about 25 V,
0-65V, finishing processing (third cut and force cut) for improving the surface roughness, which is the second processing step described above.
When a discharge occurs in the first half-wave of one cycle of the AC voltage, as shown in the discharge current waveform d, a high-frequency high-frequency AC voltage which is preferably applicable to the following is obtained. Then, a discharge occurs, but the finishing can be advanced at a value where the average machining current is smaller than about 1 A. For example, the positive and negative about 150-170V,
A high-frequency AC voltage of about 1 MHz, a processing surface finished to about 10 to 13 μmRmax up to the second cut processing of the first processing step is processed by a third cut of the second processing step to obtain about 3.5 μmRmax or It can be finished more than that, and it is about 1.5μ
It is finished to about mRmax.
【0027】そして、これは開閉スイッチ48により放
電状態検出回路が、浮遊静電容量が非常に小さい本発明
の放電状態検出回路41〜47に切換えられ、又電圧パ
ルス源5中の電圧パルス供給回路6が開閉スイッチ49
により切り離されていて高周波交流電圧の吸収・減衰が
少なく、かつ好適なサーボ制御の下に仕上げ加工が進行
せしめられるからである。そしてまた、高周波交流電圧
c間の休止時間ATOFFがより小さい、更には連続に
近い設定の場合には、放電間隙の平均電圧が所定レベル
以下の電圧検出となったときとか、所定の設定した周期
(100μS〜10ms毎に)、例えば10〜100μ
s程度の間、スイッチ素子8Bのオン・オフを停止させ
る必要があるのは安全上当然である。The discharge state detection circuit is switched to the discharge state detection circuits 41 to 47 of the present invention having a very small floating capacitance by the open / close switch 48, and the voltage pulse supply circuit in the voltage pulse source 5 is switched. 6 is an open / close switch 49
This makes it possible to reduce the absorption and attenuation of the high-frequency AC voltage, and to allow the finishing to proceed under suitable servo control. In addition, when the pause time AT OFF between the high-frequency AC voltages c is set to be shorter or more nearly continuous, when the average voltage of the discharge gap is detected to be equal to or lower than a predetermined level, or when a predetermined setting is made. Period (every 100 μS to 10 ms), for example, 10 to 100 μ
It is natural for safety that it is necessary to stop the ON / OFF of the switch element 8B for about s.
【0028】 なお、上述の間歇的な電圧パルス源5を
使用する加工に於ては、通常の電圧パルス供給回路6
に、放電電流振幅(Ip)を著増させる電流パルス供給
回路8を付加並用し、コンデンサ充放電の際のような高
い放電電流振幅の放電を行なわせるようにしているた
め、その際には放電状態検出回路を浮遊容量の小さい検
出回路41〜47に切換える等の必要は生じないのであ
るが、前記回路6と回路8とを切り離し及び接続自在に
構成し、前記通常の電圧パルス供給回路6より微小電圧
パルスを供給して前記第2の加工工程のサードカット、
更にはフォースカット等の加工面粗度出し仕上げ加工を
するようにした場合には、前述本発明の放電状態検出回
路の浮遊容量の少ない検出回路41〜47への切換え
は、有用かつ有効なものであることは既に明らかであ
る。図4は、本発明の更に好ましい改良された放電間隙
の放電状態検出回路41〜47を有する前述図1と同様
な実施例ブロックダイヤグラム説明図で、前述図1との
相違点は、前記放電状態検出回路41〜47の入力部フ
ォトカプラ41の発光素子41Aと直列な入力抵抗41
Cを、放電間隙に近い位置に設けられる電流制限用の大
容量・高抵抗値の分圧抵抗41C−1と、放電間隙から
離隔した検出回路41〜47や制御装置38等が設けら
れる電源装置や制御部側に設けられる前記の分圧抵抗4
1C−2との直列接続体から成る構成としたもので、図
中一点破線50の左側、分圧抵抗41C−1のある側が
放電加工機本体側で、好ましくは放電間隙に供給される
加工液と接触するように、図示しない加工槽等の部分に
配置され、前記一点破線50の右側は前述電源装置や制
御部側であるが、機械的開閉スイッチ48は、一点破線
50の左側の機械本体側等適宜の位置に設けることがで
きる。即ち、前述図1の構成で、放電状態検出回路41
〜47を放電間隙に接続し、前述図2の如き高周波交流
電圧源30により加工面粗度出しの放電仕上げ加工を行
なうと、前記高周波交流電圧の周波数は約1MHz程度
又はそれ以上の高周波で、正負のピーク・ツウ・ピーク
の電圧は約350〜500Vの高電圧である所から、検
出回路41〜47の上記入力抵抗41Cとしては、抵抗
値が約3KΩ程度で、定格容量約20W程度のものが冷
却ファン等の冷却手段付きで必要となり、設置スペース
等が必要となる丈でなく、放電間隙から検出回路41〜
47のある電源装置や制御部へ検出回路リード線を引き
廻して来ると、近くにある制御回路等の各種の回路に各
種の誤作動等の雑音障害を生じさせ、加工制御作動や加
工が巧く進行しないと言うことが少なくなかったもので
ある。そこで、本発明では、前記入力抵抗41Cを、高
抵抗値、例えば約2.5KΩで、大容量、例えば約20
Wの電流制限用の分圧抵抗41C−1と、低抵抗値、例
えば100Ωで小容量、例えば1〜2Wの第2の分圧抵
抗41C−2との2つに分けて直列にした構成とし、そ
して前者の電流制限用の分圧抵抗41C−1を放電加工
機側に、そして冷却のために放電間隙等の加工部を収納
する加工槽中の加工液中に浸漬するか、加工槽又は加工
部に供給する加工液を必要に応じて分流噴射等させる構
成として冷却するようにするものである。そして、かく
することにより、検出回路内に設けられる第2の分圧抵
抗41C−2は格別のスペースを要せず、又放電間隙電
圧は充分に分圧(約1/26)されて検出回路に入力す
るので近くにある制御回路等の雑音障害も生じなくな
る。図5は前記電流制限用の分圧抵抗41C−1がワイ
ヤ放電加工機本体の加工槽部分に設けられた状態の一例
を示す説明図で、被加工体3を載置するワークスタンド
4は、図示しないベッド上のクロステーブルに取り付け
られた加工槽内に設けられ、被加工体3は必要に応じて
加工液中に浸漬された状態で、ガイド2A、2Bを内包
する加工液噴射ノズル18A、18B間を更新移動する
ワイヤ電極1により切断、切抜き等のワイヤ放電加工さ
れるもので、前記放電加工用電源の出力端子の一方(正
極側)が前記ワークスタンド4に、そして他方がノズル
18A、18B内でワイヤ電極1と接触する図示しない
給電子に端子19A、19Bを介して接続されている。
而して、前記分圧抵抗41C−1としては、好ましくは
無誘導性の、かつ耐水性のセメント抵抗、メタルクラッ
ド抵抗、又は琺瑯抵抗等で、取付台兼放熱フィン台20
に取り付けられて加工槽内のワークスタンド4廻り等適
宜の位置に設置され、一方の端子41C−1Aはワーク
スタンド4(又はノズル18B部の端子19B)に、そ
して他方の端子41C−1Bが電源装置や制御部と加工
機本体間の検出信号電送用の同軸ケーブル21の一方の
端子21B、そして該同軸ケーブル21の他方の端子2
1Aがノズル18Bの端子19B(又はワークスタンド
4)に接続される。前記分圧抵抗41C−1は加工槽中
の加工液中に浸漬冷却されるか、図示のようにノズル1
8A、18Bの加工液供給管22から分岐した管路22
A(又は独立に設けた管路)によって供給される冷却ノ
ズル23の噴射加工液により所望に冷却される。図6の
A、及びBは検出回路の分圧抵抗回路の変形例を示すも
ので、既述の如く本発明に於ける分圧抵抗回路は検出回
路の入出力端子間(19B又は21Aと41C−1B又
は21B間等)、又は線間電圧を低くするための構成で
あるから、A図のように機械本体側出力端子21Aと2
1B間に分圧抵抗41C−1Cを接続するか、B図のよ
うに電源装置や制御部の入力、同軸ケーブル21の他端
の抵抗41C−2と発光素子41Aとの直列回路に並列
に分圧抵抗41C−2Cを接続し、検出回路入力電圧の
低減させる構成も有効なものである。In the above-described processing using the intermittent voltage pulse source 5, a normal voltage pulse supply circuit 6 is used.
In addition, a current pulse supply circuit 8 for significantly increasing the discharge current amplitude (Ip) is additionally used, and a discharge with a high discharge current amplitude is performed as in the case of charging and discharging a capacitor. It is not necessary to switch the state detection circuit to the detection circuits 41 to 47 having small stray capacitances. However, the circuit 6 and the circuit 8 are configured to be detachable and freely connectable, and the normal voltage pulse supply circuit 6 is used. A third cut of the second processing step by supplying a minute voltage pulse;
Further, in the case of performing a finishing process such as forcing the workpiece surface to a roughened surface, the switching to the detection circuits 41 to 47 having a small stray capacitance of the discharge state detection circuit of the present invention is useful and effective. It is already clear that FIG. 4 is an explanatory block diagram of an embodiment similar to FIG. 1 having a more preferable and improved discharge gap detection circuit 41 to 47 of the present invention. The difference from FIG. An input resistor 41 in series with the light emitting element 41A of the input section photocoupler 41 of the detection circuits 41 to 47
C is a power supply device provided with a large-capacity, high-resistance voltage-dividing resistor 41C-1 provided at a position close to the discharge gap, and detection circuits 41 to 47, a control device 38, and the like separated from the discharge gap. And the voltage dividing resistor 4 provided on the control unit side.
The machining fluid is supplied to the electric discharge machine main body, and the left side of the one-dot broken line 50 in FIG. The right side of the dashed line 50 is the power supply unit and the control unit side, but the mechanical open / close switch 48 is
It can be provided at an appropriate position such as the machine body side on the left side of 50 . That is, in the configuration of FIG.
To 47 are connected to the discharge gap, and the discharge finish machining for obtaining the machining surface roughness is performed by the high-frequency AC voltage source 30 as shown in FIG. 2, the frequency of the high-frequency AC voltage is about 1 MHz or higher, Since the positive-negative peak-to-peak voltage is a high voltage of about 350 to 500 V, the input resistance 41C of the detection circuits 41 to 47 has a resistance of about 3 KΩ and a rated capacity of about 20 W. Is required with a cooling means such as a cooling fan, and is not long enough to require an installation space.
When the detection circuit lead wire is routed to a power supply device or control unit with 47, various circuits such as a control circuit nearby will cause various malfunctions and other noise disturbances, and the machining control operation and machining will be skillful. It was not uncommon to say that it did not progress. Therefore, in the present invention, the input resistance 41C is set to a high resistance value, for example, about 2.5 KΩ, and a large capacity, for example, about 20 KΩ.
A voltage dividing resistor 41C-1 for limiting current of W and a second resistor 41C-2 having a low resistance value, for example, 100Ω and a small capacity, for example, 1 to 2W, are divided into two parts and are configured in series. And, the former voltage-dividing resistor 41C-1 for limiting the current is immersed in the machining fluid in the machining tank containing the machining part such as the discharge gap for cooling, and the machining tank or The processing fluid to be supplied to the processing section is cooled by a configuration in which the processing liquid is jetted if necessary. By doing so, the second voltage-dividing resistor 41C-2 provided in the detection circuit does not require a special space, and the discharge gap voltage is sufficiently divided (about 1/26), so that the detection circuit , No noise disturbance occurs in nearby control circuits and the like. FIG. 5 is an explanatory view showing an example of a state in which the current-limiting voltage dividing resistor 41C-1 is provided in the machining tank portion of the wire electric discharge machine main body. The work stand 4 on which the workpiece 3 is placed is: The workpiece 3 is provided in a processing tank attached to a cross table on a bed (not shown), and the workpiece 3 is immersed in a processing liquid as required, and a processing liquid injection nozzle 18A including guides 2A and 2B, Wire discharge machining such as cutting and cutting is performed by the wire electrode 1 that moves between 18B. One of the output terminals of the power supply for electric discharge machining (positive electrode side) is on the work stand 4 and the other is the nozzle 18A. The terminal 18A is connected to a power supply (not shown) that contacts the wire electrode 1 via terminals 19A and 19B.
Thus, the voltage dividing resistor 41C-1 is preferably a non-inductive and water-resistant cement resistor, metal clad resistor, or enamel resistor, etc.
And one of the terminals 41C-1A is connected to the work stand 4 (or the terminal 19B of the nozzle 18B), and the other terminal 41C-1B is connected to a power supply. One terminal 21B of the coaxial cable 21 for transmitting a detection signal between the device or the control unit and the processing machine main body, and the other terminal 2 of the coaxial cable 21
1A is connected to the terminal 19B (or the work stand 4) of the nozzle 18B. The partial pressure resistor 41C-1 is immersed and cooled in a processing liquid in a processing tank, or a nozzle 1 as shown in the drawing.
8A, 18B, a pipeline 22 branched from the machining fluid supply pipe 22
A (or an independently provided pipe line) cools as desired by the jet processing liquid of the cooling nozzle 23 supplied. 6A and 6B show a modification of the voltage dividing resistor circuit of the detection circuit. As described above, the voltage dividing resistor circuit of the present invention is provided between the input / output terminals of the detection circuit (19B or 21A and 41C). -1B or 21B) or the line voltage is reduced, so that the machine body side output terminals 21A and 21A are connected as shown in FIG.
A voltage dividing resistor 41C-1C is connected between 1B, or is divided in parallel with a series circuit of a resistor 41C-2 at the other end of the coaxial cable 21 and a light emitting element 41A as shown in FIG. A configuration in which the piezoresistors 41C-2C are connected to reduce the input voltage of the detection circuit is also effective.
【0029】以上、本発明の放電加工装置に付き、図示
した実施例により説明を加えたが、本発明は特許請求の
範囲に記載する本発明の精神を逸脱しない範囲で各部に
各種の変更を加えて実施し得るものである。例えば、図
2に於て、電流パルス供給回路8が設けられていない形
式のワイヤ放電加工用電源回路の場合は、間歇電圧パル
ス発生回路6の電流制限抵抗6Dを短絡等させる抵抗低
減回路を付設し、スイッチ素子6Bのゲート信号回路に
ゲート信号回路8Dを切換え接続する構成としても良
く、又ゲート信号回路8Dは、パルス制御装置7内にそ
の一部の構成として内設構成し得るだけだなく、さらに
制御装置7内に於て、記憶した切換制御データを読み出
す等してソフト的に切換え作動せしめ得るものであり、
又更に、仕上げ加工用高周波交流電圧の更なる高周波
化、例えば2MHzとするために、例えば電流パルス供
給回路8を2組並列に設け、例えば夫々をτON=10
0nsで、τOFF=900nsの1MHzの高周波
(電流)パルス発生回路の2組を約180°(π)位相
差を有せしめて、高周波交流電圧の1サイクルが約50
0ns以内で終了するように調整すればよく、又更に前
記高周波交流電圧源としても、これを通常の例えば、ト
ランジスタインバータ方式の高周波交流電圧源とし、之
を整合回路を介して放電間隙に接続する方式のものも用
い得るものであり、かかる構成変更は本発明の各部に於
て可能なものである。As described above, the electric discharge machine according to the present invention has been described with reference to the illustrated embodiment. However, the present invention may be modified in various ways without departing from the spirit of the present invention described in the appended claims. In addition, it can be implemented. For example, in FIG. 2, in the case of a power supply circuit for wire electric discharge machining in which the current pulse supply circuit 8 is not provided, a resistance reducing circuit for short-circuiting the current limiting resistor 6D of the intermittent voltage pulse generating circuit 6 is provided. Alternatively, the gate signal circuit 8D may be switched and connected to the gate signal circuit of the switch element 6B. The gate signal circuit 8D can be provided not only as a part of the pulse control device 7 but also internally. Further, in the control device 7, the stored switching control data can be read out or the like to perform the switching operation by software.
Furthermore, in order to further increase the high-frequency AC voltage for finishing processing, for example, to 2 MHz, two sets of current pulse supply circuits 8 are provided in parallel, for example, each having τ ON = 10.
At 0 ns, two sets of 1 MHz high frequency (current) pulse generating circuits of τ OFF = 900 ns have a phase difference of about 180 ° (π), and one cycle of the high frequency AC voltage is about 50
It may be adjusted so as to be completed within 0 ns. Further, as the high-frequency AC voltage source, a normal, for example, transistor-inverter-type high-frequency AC voltage source is used, and this is connected to the discharge gap via a matching circuit. Such a configuration change can be made in each part of the present invention.
【発明の効果】本発明の放電加工装置は、上述のような
構成であるから、仕上げ加工に際し放電間隙に接続され
ている放電状態検出回路は、抵抗とフォトカプラの発光
素子とを直列に接続した直列回路部分のみで、前記フォ
トカプラ以後の積分回路や増幅回路、或いは更にサンプ
ルホールド増幅回路やA/D変換器等は前記フォトカプ
ラにより放電間隙から絶縁されており、又この検出回路
とは必要に応じて別異に設けられる他の検出回路等は、
機械的開閉スイッチにより切り離されるので、放電間隙
に対して設けられる放電状態検出回路による浮遊容量を
最小の状態とすることができ、仕上げ加工を好適にサー
ボ制御をした状態で、加工面荒れがなく所定の微細面粗
度に、かつ効率良い加工ができるようになる。又、本発
明によれば、前記発光素子と直列な抵抗を、前記放電間
隙に近い位置に設けられる電流制限用の分圧抵抗と放電
間隙から離隔した電源装置の検出回路側に設けられる第
2の分圧抵抗との直列接続体により構成したので、放電
状態検出回路や該回路が設けられる電源装置や制御部等
に高周波高電圧による雑音障害を生じさせることがな
く、高周波交流電圧源を放電加工の仕上げ加工用電源と
して安全かつ有効に利用することができるようになっ
た。Since the electric discharge machining apparatus of the present invention has the above-described configuration, the discharge state detection circuit connected to the discharge gap at the time of finishing machining connects the resistor and the light emitting element of the photocoupler in series. Only the serial circuit portion described above, the integrating circuit and the amplifying circuit after the photocoupler, or further the sample-hold amplifying circuit and the A / D converter are insulated from the discharge gap by the photocoupler. Other detection circuits etc. provided separately as necessary are
Since it is separated by the mechanical opening / closing switch, the stray capacitance by the discharge state detection circuit provided for the discharge gap can be minimized, and the finished surface is preferably servo-controlled, so that the machining surface is not roughened. Efficient processing can be performed with a predetermined fine surface roughness. Further, according to the present invention, a resistor in series with the light emitting element is provided with a current-limiting voltage dividing resistor provided at a position close to the discharge gap and a second resistor provided on a detection circuit side of a power supply device separated from the discharge gap. The high-frequency AC voltage source is discharged without causing a high-frequency high-voltage noise disturbance in the discharge state detection circuit and the power supply device and the control unit in which the circuit is provided. It can be used safely and effectively as a power source for finishing.
【図1】本発明の放電状態検出回路の実施例を示すブロ
ックダイアグラム図。FIG. 1 is a block diagram showing an embodiment of a discharge state detection circuit according to the present invention.
【図2】図1の放電加工用電源回路部分の一詳細例を示
す回路構成図。FIG. 2 is a circuit diagram showing a detailed example of a power supply circuit portion for electric discharge machining in FIG. 1;
【図3】図2の回路を仕上げ加工用電源回路として作動
させたときの一部分のタイミングチャート図。FIG. 3 is a partial timing chart when the circuit of FIG. 2 is operated as a power supply circuit for finishing processing.
【図4】本発明の改良された放電状態検出回路の実施例
を示すブロックダイヤグラム図。FIG. 4 is a block diagram showing an embodiment of the improved discharge state detection circuit of the present invention.
【図5】本発明の実施例の部分の構成を示す説明図。FIG. 5 is an explanatory diagram showing a configuration of a portion of the embodiment of the present invention.
【図6】A、B 本発明実施例の部分の変形例を示す回路説明図。FIGS. 6A and 6B are circuit explanatory diagrams showing modified examples of portions of the embodiment of the present invention.
【図7】従来例の放電状態検出回路のブロックダイアグ
ラム図。FIG. 7 is a block diagram of a conventional discharge state detection circuit.
1,ワイヤ電極、加工用電極 2A,2B,位置決ガイド 3,被加工体 4,ワークスタンド 5,ワイヤ放電加工用電圧パルス源 6,電圧パルスの生成供給回路 6A,直流電圧源 6B,電子スイッチ素子 6C,電流制限抵抗 6D,逆電圧防止整流器 7,パルス制御装置 8,電流電流パルス供給回路 8A,可変直流電圧源 8B,電子スイッチ素子 8C,逆電圧防止整流器 8D,ゲート信号回路 8E,切換えスイッチ 10,高周波電流パルス発生回路 11A,11B,給電接続線 12,回路装置 13,高周波結合トランス 13A,リングコア 13B,1次巻線 13C,2次巻線 14A,14B,14C,14D,開閉スイッチ 18A,18B,加工液噴射ノズル 19A,19B,端子 20,抵抗取付台 21,同軸ケーブル 22,加工液供給管 23,冷却ノズル 30,仕上げ加工用電源 31,放電間隙電圧検出用分圧回路 32,42,反転増幅回路 33,43A,43B,積分回路 34,44,利得調整回路 35,45,サンプルホールド増幅器 36,46,A/D変換器 37,41,47,フォトカプラ 38,制御装置 39,モータドライバ 40,サーボモータ 41A,発光素子 41B,受光素子 41C,抵抗 41C−1,41C−2,41C−1C,41C−2
C,分圧抵抗 41D,整流器 48,49,開閉スイッチ1, wire electrode, machining electrode 2A, 2B, positioning guide 3, workpiece 4, work stand 5, voltage pulse source for wire electric discharge machining 6, voltage pulse generation and supply circuit 6A, DC voltage source 6B, electronic switch Element 6C, current limiting resistor 6D, reverse voltage prevention rectifier 7, pulse control device 8, current / current pulse supply circuit 8A, variable DC voltage source 8B, electronic switch element 8C, reverse voltage prevention rectifier 8D, gate signal circuit 8E, changeover switch 10, high-frequency current pulse generation circuits 11A and 11B, power supply connection line 12, circuit device 13, high-frequency coupling transformer 13A, ring core 13B, primary winding 13C, secondary windings 14A, 14B, 14C, 14D, open / close switch 18A, 18B, machining fluid injection nozzle 19A, 19B, terminal 20, resistance mount 21, coaxial cable 22, Working fluid supply pipe 23, cooling nozzle 30, finishing power supply 31, voltage divider circuits 32, 42 for detecting discharge gap voltage, inverting amplifier circuits 33, 43A, 43B, integrating circuits 34, 44, gain adjusting circuits 35, 45, Sample hold amplifiers 36, 46, A / D converters 37, 41, 47, photocoupler 38, control device 39, motor driver 40, servo motor 41A, light emitting element 41B, light receiving element 41C, resistors 41C-1, 41C-2. , 41C-1C, 41C-2
C, voltage dividing resistor 41D, rectifier 48, 49, open / close switch
───────────────────────────────────────────────────── フロントページの続き 審査官 神崎 孝之 (56)参考文献 特開 平5−177435(JP,A) 特開 昭56−163830(JP,A) 特開 平5−285731(JP,A) 特開 昭51−85593(JP,A) 特開 平4−250920(JP,A) 特開 平2−30422(JP,A) 特開 平6−8049(JP,A) 特開 昭63−200920(JP,A) 特公 昭60−13769(JP,B2) (58)調査した分野(Int.Cl.7,DB名) B23H 1/02 ──────────────────────────────────────────────────続 き Continuation of the front page Examiner Takayuki Kanzaki (56) References JP-A-5-177435 (JP, A) JP-A-56-163830 (JP, A) JP-A-5-2875731 (JP, A) JP-A-51-85593 (JP, A) JP-A-4-250920 (JP, A) JP-A-2-30422 (JP, A) JP-A-6-8049 (JP, A) JP-A-63-200920 (JP) JP, A) JP-B-60-13769 (JP, B2) (58) Fields investigated (Int. Cl. 7 , DB name) B23H 1/02
Claims (7)
て有する高周波結合トランスと、前記1次巻線に間歇的
に高周波の電流パルスを供給する電流パルス供給回路と
を有し、前記2次巻線に誘起される高周波交流電圧を加
工電極と被加工体間の放電間隙に供給して仕上げ加工す
る仕上げ加工用電圧供給回路を備え、抵抗と発光素子と
の直列回路を前記放電間隙に直接並列に接続し、前記発
光素子の発光出力を光一電気信号変換の受光素子により
電気信号に変換して前記放電間隙の放電状態検出信号を
得るようにした放電状態検出回路を含む別異複数の放電
状態検出回路が前記放電間隙に並列に接続して設けら
れ、 加工に際して前記高周波交流電圧の仕上げ加工用電圧供
給回路を使用するとき、前記直列回路を有する放電状態
検出回路以外の放電状態検出回路を放電間隙から切り離
す機械的開閉スイッチが、上記直列回路を有する放電状
態検出回路以外の放電状態検出回路と放電間隙との間に
設けられていることを特徴とする放電加工装置。1. A high-frequency coupling transformer having primary and secondary windings wound around a ring core, and a current pulse supply circuit for intermittently supplying a high-frequency current pulse to the primary winding, A finishing machining voltage supply circuit for supplying a high-frequency AC voltage induced in the secondary winding to a discharge gap between the machining electrode and the workpiece to perform finishing, and connecting a series circuit of a resistor and a light emitting element to the discharge gap; A plurality of discharge state detection circuits, which are directly connected in parallel to each other, and convert a light emission output of the light emitting element into an electric signal by a light receiving element of photoelectric conversion to obtain a discharge state detection signal of the discharge gap. A discharge state detection circuit is provided in parallel with the discharge gap, and when a finishing machining voltage supply circuit for the high-frequency AC voltage is used in machining, a circuit other than the discharge state detection circuit having the series circuit is provided. Mechanical off switch for disconnecting the electricity state detection circuit from the discharge gap, discharge machining apparatus, characterized in that provided between the discharge state detecting circuit other than the discharge state detection circuit having the above-mentioned series circuit and the discharge gap.
の電圧パルスを休止時間を置いて間歇的に供給する加工
用電圧パルス供給回路と、高周波交流電圧を加工電極と
被加工体間の放電間隙に供給する仕上げ加工用電圧供給
回路とを備え、 放電状態検出回路は、必要に応じて設けられる開閉スイ
ッチにより、必要に応じて放電間隙に接離されるもので
あって、 抵抗と発光素子との直列回路を前記放電間隙に直接並列
に接続し、前記発光素子の発光出力を光一電気信号変換
の受光素子により電気信号に変換して前記放電間隙の放
電状態検出信号を得るようにした放電状態検出回路と、 前記発光素子を含む放電状態検出回路とは別異の前記放
電間隙に並列に接続される電圧検出回路を有する少なく
とも1つの放電状態検出回路とを有し、 得られる放電状態検出信号により加工送りその他の制御
要素を制御する仕上げ加工に際して、前記高周波交流電
圧供給回路以外の電圧パルス供給回路、及び上記発光素
子を含む放電状態検出回路以外の放電間隙に接続されて
いる放電状態検出回路を機械的開閉スイッチにより放電
間隙から切り離すように構成して成ることを特徴とする
放電加工装置。2. A processing voltage pulse supply circuit for intermittently supplying at least a voltage pulse for normal processing with a pause time as a processing power source, and a high-frequency AC voltage applied to a discharge gap between the processing electrode and the workpiece. And a voltage supply circuit for finishing machining to be supplied.The discharge state detection circuit is connected to and separated from the discharge gap as necessary by an on-off switch provided as necessary, and is connected in series with the resistor and the light emitting element. A discharge state detection circuit in which a circuit is directly connected in parallel with the discharge gap, and a light emission output of the light emitting element is converted into an electric signal by a light-receiving element of photoelectric conversion to obtain a discharge state detection signal of the discharge gap. And at least one discharge state detection circuit having a voltage detection circuit connected in parallel to the discharge gap different from the discharge state detection circuit including the light emitting element. At the time of finishing processing in which machining control and other control elements are controlled by the discharge state detection signal, it is connected to a voltage pulse supply circuit other than the high-frequency AC voltage supply circuit and a discharge gap other than the discharge state detection circuit including the light emitting element. An electric discharge machining apparatus characterized in that the electric discharge state detecting circuit is configured to be separated from the electric discharge gap by a mechanical open / close switch.
間隙に近い位置に設けられる電流制限用の分圧抵抗と放
電間隙から離隔した電源装置の検出回路側に設けられる
第2の分圧抵抗との直列接続体により構成して成ること
を特徴とする前記請求項1、または2に記載の放電加工
装置。3. A current dividing voltage dividing resistor provided in a position close to the discharge gap and a second voltage dividing provided on a detection circuit side of a power supply device separated from the discharge gap by connecting a resistor in series with the light emitting element. 3. The electric discharge machining apparatus according to claim 1, wherein the electric discharge machining apparatus is configured by a series connection with a resistor.
の分圧抵抗の分圧値に対して充分大きな分圧値を負荷す
る関係の抵抗値に選定され、かつ前記電流制限用の分圧
抵抗が放電間隙に供給される加工液と接触して冷却され
るように加工槽部に配置されて成ることを特徴とする前
記請求項3に記載の放電加工装置。4. The current-limiting voltage-dividing resistor according to claim 2, wherein
The voltage dividing resistor is selected to have a relationship of applying a sufficiently large voltage dividing value to the voltage dividing value of the voltage dividing resistor, and the current limiting voltage dividing resistor is brought into contact with the machining fluid supplied to the discharge gap for cooling. The electric discharge machining device according to claim 3, wherein the electric discharge machining device is arranged in a machining tank portion so as to perform the operation.
を接続して成ることを特徴とする請求項1、2、3、又
は4に記載の放電加工装置。5. The electric discharge machining apparatus according to claim 1, wherein a rectifying element is connected in parallel with the light emitting element with a reverse polarity.
光素子がフォトトランジスタ又はフォトダイオードであ
る前記請求項1、2、3、4又は5に記載の放電加工装
置。6. The electric discharge machining apparatus according to claim 1, wherein the light emitting element is a light emitting diode, and the light receiving element is a phototransistor or a photodiode.
電間隙を送りにより制御するサーボ送り制御装置の放電
間隙検出信号とするようにした請求項1、2、3、4、
5、又は6に記載の放電加工装置。7. A discharge gap detection signal of a servo feed control device for controlling a discharge gap by feeding a discharge gap detection signal of the discharge state detection circuit.
The electric discharge machine according to 5 or 6.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP33470394A JP3311530B2 (en) | 1994-04-15 | 1994-12-07 | Electric discharge machine |
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP11333294 | 1994-04-15 | ||
JP6-113332 | 1994-04-15 | ||
JP33470394A JP3311530B2 (en) | 1994-04-15 | 1994-12-07 | Electric discharge machine |
Publications (2)
Publication Number | Publication Date |
---|---|
JPH07328844A JPH07328844A (en) | 1995-12-19 |
JP3311530B2 true JP3311530B2 (en) | 2002-08-05 |
Family
ID=26452327
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP33470394A Expired - Fee Related JP3311530B2 (en) | 1994-04-15 | 1994-12-07 | Electric discharge machine |
Country Status (1)
Country | Link |
---|---|
JP (1) | JP3311530B2 (en) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US9452483B2 (en) * | 2012-11-14 | 2016-09-27 | General Electric Company | Electric discharge machining die sinking device and related method of operation |
Family Cites Families (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5185593A (en) * | 1975-01-23 | 1976-07-27 | Hitachi Shipbuilding Eng Co | IJOHODENKAKOJOTAINOKENSHUTSUHOHO |
JPS6013769B2 (en) * | 1975-03-27 | 1985-04-09 | 株式会社井上ジャパックス研究所 | Electric discharge machining equipment |
JPS56163830A (en) * | 1980-05-13 | 1981-12-16 | Inoue Japax Res Inc | Pulse power source |
JPS63200920A (en) * | 1986-10-07 | 1988-08-19 | Mitsubishi Electric Corp | Workpiece attaching jig for wire electric discharge machine |
JPH0230422A (en) * | 1988-07-20 | 1990-01-31 | Hitachi Seiko Ltd | Electric discharge machining device |
JPH04250920A (en) * | 1990-12-28 | 1992-09-07 | I N R Kenkyusho:Kk | Electric discharging device |
JPH05177435A (en) * | 1991-12-26 | 1993-07-20 | I N R Kenkyusho:Kk | Electric discharge machining device |
JPH05285731A (en) * | 1992-04-06 | 1993-11-02 | I N R Kenkyusho:Kk | Electric discharge machine |
JPH068049A (en) * | 1992-06-26 | 1994-01-18 | Fanuc Ltd | Electric discharge machining device |
-
1994
- 1994-12-07 JP JP33470394A patent/JP3311530B2/en not_active Expired - Fee Related
Also Published As
Publication number | Publication date |
---|---|
JPH07328844A (en) | 1995-12-19 |
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