JPH11226816A

JPH11226816A - Electric discharge machining device and electric discharge machining method

Info

Publication number: JPH11226816A
Application number: JP3177298A
Authority: JP
Inventors: Masanari Nagata; 真生永田; Maki Yamada; 真樹山田; Kimihiro Wakabayashi; 公宏若林; Yoshio Suzuki; 良雄鈴木
Original assignee: Fuji Xerox Co Ltd
Current assignee: Fujifilm Business Innovation Corp
Priority date: 1998-02-13
Filing date: 1998-02-13
Publication date: 1999-08-24

Abstract

PROBLEM TO BE SOLVED: To prevent breakage of a discharge electrode, reduce electric discharge machining time, and enable machining in a minute area. SOLUTION: A controller 5 of a machine controls an XY axes table 41 and a Z axis table 40 for decelerating in moving in the XY axes and Z axis when a discharge starting/short-circuiting determination part 9 senses an electric discharge machining state between an electric discharge machining electrode 2 and a workpiece 3 to be machined. The controller 5 controls the Z axis table 40 for moving the electrode 2 in the direction of the Z axis, for separating from the workpiece 5 when the determination part 9 senses short-circuitting state between the electrode 2 and the workpiece 3.

Description

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

【０００１】[0001]

【発明の属する技術分野】本発明は、放電加工装置に関
し、特に、コンデンサ放電回路を用いて被加工物の微小
領域を放電加工する放電加工装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric discharge machine, and more particularly, to an electric discharge machine which discharges a minute area of a workpiece using a capacitor discharge circuit.

【０００２】[0002]

【従来の技術】従来の放電加工装置として、例えば、特
開昭６３−２２９２２４号公報に示されるものがある。
この放電加工装置は、放電加工機から出力される出力パ
ルスの平均値付近以下に設定された閾値電圧を用い、出
力パルスが閾値電圧より大きいときに信号を出力する比
較回路と、比較回路の出力を計数するカウンタと、カウ
ンタの計数値が所定の出力回数以下か否かを判断する判
断部とを備えるものである。判断部によりカウンタの計
数値が所定の出力回数以下であると判断されたとき、放
電電極と被加工物との接触による短絡状態が検出され
る。2. Description of the Related Art As a conventional electric discharge machining apparatus, for example, there is one disclosed in Japanese Patent Application Laid-Open No. 63-229224.
This electric discharge machine uses a threshold voltage set to be less than or equal to an average value of output pulses output from the electric discharge machine, and outputs a signal when the output pulse is larger than the threshold voltage; And a determining unit for determining whether the count value of the counter is equal to or less than a predetermined number of outputs. When the determination unit determines that the count value of the counter is equal to or less than the predetermined number of times of output, a short-circuit state due to contact between the discharge electrode and the workpiece is detected.

【０００３】[0003]

【発明が解決しようとする課題】しかし、従来の放電加
工装置によると、放電状態を検出するためには、出力パ
ルスを短絡状態を検出するカンウト値に応じた複数の放
電周期にわたって測定し続けることが必要となるため、
放電状態を検出するまで一定以上の時間を要することに
なることから、この間の放電電極の送り動作によって放
電電極に過大な力が加わり放電電極が折損するおそれが
ある。特に、微細な放電電極を用いて微小領域を放電加
工する場合は、折損の発生率が高くなる。一方、放電電
極の折損を回避すべく、放電電極の送り速度を遅くした
のでは、加工時間が長くなるという問題を生ずる。ま
た、放電加工回路として放電エネルギーの大きいトラン
ジスタ回路を用いているため、ミクロンオーダの微小領
域を加工することは難しい。However, according to the conventional electric discharge machining apparatus, in order to detect a discharge state, it is necessary to continuously measure an output pulse over a plurality of discharge cycles corresponding to a count value for detecting a short circuit state. Is required,
Since it takes a certain amount of time to detect the discharge state, an excessive force is applied to the discharge electrode by the feeding operation of the discharge electrode during this time, and the discharge electrode may be broken. In particular, when a minute area is subjected to electric discharge machining using a minute discharge electrode, the rate of occurrence of breakage increases. On the other hand, if the feed speed of the discharge electrode is reduced in order to avoid breakage of the discharge electrode, there is a problem that the machining time becomes longer. Further, since a transistor circuit having a large discharge energy is used as the electric discharge machining circuit, it is difficult to machine a micro area on the order of microns.

【０００４】従って、本発明の目的は、放電電極の折損
を防止するとともに、加工時間の短縮化を図り、微小領
域を加工可能な放電加工方法および放電加工装置を提供
することにある。Accordingly, an object of the present invention is to provide an electric discharge machining method and an electric discharge machining apparatus capable of preventing a breakage of a discharge electrode, shortening a machining time, and machining a minute area.

【０００５】[0005]

【課題を解決するための手段】本発明は、上記目的を達
成するため、放電電極を所定の加工速度で被加工物に対
して相対的に移動させつつ、コンデンサ放電回路により
前記放電電極と前記被加工物との間で放電させて前記被
加工物を放電加工する放電加工方法において、前記放電
電極を前記所定の加工速度より高速の移動速度で前記放
電電極が前記被加工物に近づく方向に前記被加工物に対
して相対的に移動させ、前記放電電極と前記被加工物と
の間の放電開始状態を検出したとき、前記放電電極の移
動速度を前記所定の加工速度に切り替えることを特徴と
する放電加工方法を提供する。本発明は、上記目的を達
成するため、コンデンサ放電回路により放電電極と被加
工物との間で所定の周期で放電させて前記被加工物を放
電加工する放電加工方法において、前記放電電極を前記
放電電極が前記被加工物に近づく方向に前記被加工物に
対して相対的に移動させ、前記所定の周期毎に前記放電
電極と前記被加工物との間の短絡状態の有無を検出し、
前記短絡状態を検出したとき、前記放電電極を前記放電
電極が前記被加工物から離れる方向に前記被加工物に対
して相対的に移動させることを特徴とする放電加工方法
を提供する。本発明は、上記目的を達成するため、放電
電極を所定の加工速度で被加工物に対して相対的に移動
させつつ、コンデンサ放電回路により前記放電電極と前
記被加工物との間で所定の周期で放電させて前記被加工
物を放電加工する放電加工方法において、前記放電電極
を前記所定の加工速度より高速の移動速度で前記放電電
極が前記被加工物に近づく方向に前記被加工物に対して
相対的に移動させ、前記放電電極と前記被加工物との間
の放電開始状態を検出したとき、前記放電電極の移動速
度を前記所定の加工速度に切り替え、前記所定の周期毎
に前記放電電極と前記被加工物との間の短絡状態の有無
を検出し、前記短絡状態を検出したとき、前記放電電極
を前記放電電極が前記被加工物から離れる方向に前記被
加工物に対して相対的に移動させることを特徴とする放
電加工方法を提供する。本発明は、上記目的を達成する
ため、コンデンサ放電回路により放電電極と被加工物と
の間で所定の周期で放電させて前記被加工物を放電加工
する放電加工方法において、前記放電電極と前記被加工
物との間の短絡時の電流値以上、放電加工時のピーク電
流値以下に第１の閾値を設定し、前記放電電極と前記被
加工物との間に流れる電流波形の最大値が前記第１の閾
値を越えたことによって前記放電電極と前記被加工物と
の間の放電開始状態を検出し、前記放電電極と前記被加
工物との間の短絡時の電流値以下に第２の閾値を設定
し、前記所定の周期毎に前記放電電極と前記被加工物と
の間に流れる電流の前記所定の周期における平均値が前
記第２の閾値を越えたか否かを判断し、前記第２の閾値
を超えたことによって前記放電電極と前記被加工物との
間の短絡状態を検出することを特徴とする放電加工方法
を提供する。本発明は、上記目的を達成するため、コン
デンサ放電回路により放電電極と被加工物との間で所定
の周期で放電させて前記被加工物を放電加工する放電加
工方法において、放電加工時の電圧値以上、放電直前の
ピーク電圧値以下に閾値を設定し、前記放電電極と前記
被加工物との間に生ずる電圧波形の最大値が前記閾値を
越えたことによって前記放電電極と前記被加工物との間
の放電開始状態を検出し、前記所定の周期毎に前記放電
電極と前記被加工物との間に生ずる電圧が０になったか
否かを判断し、０になったことによって前記放電電極と
前記被加工物との間の短絡状態を検出することを特徴と
する放電加工方法を提供する。本発明は、上記目的を達
成するため、放電電極を所定の加工速度で被加工物に対
して相対的に移動させつつ、コンデンサ放電回路により
前記放電電極と前記被加工物との間で放電させて前記被
加工物を放電加工する放電加工装置において、前記放電
電極と前記被加工物との間の放電開始状態を検出する検
出手段と、前記放電電極を前記所定の加工速度、あるい
は前記所定の加工速度より高速の移動速度で前記放電電
極が前記被加工物に近づく方向に前記被加工物に対して
相対的に移動させる移動手段と、前記放電電極を前記高
速の移動速度で移動させ、前記検出手段が前記放電開始
状態を検出したとき、前記放電電極を前記加工速度で移
動させるよう前記移動手段を制御する制御手段とを備え
たことを特徴とする放電加工装置を提供する。本発明
は、上記目的を達成するため、コンデンサ放電回路によ
り被加工物と放電電極との間で所定の周期で放電させて
前記被加工物を放電加工する放電加工装置において、前
記所定の周期毎に前記放電電極と前記被加工物との間の
短絡状態の有無を検出する検出手段と、前記放電電極
を、前記放電電極が前記被加工物に近づく方向、あるい
は前記放電電極が前記被加工物から離れる方向に相対的
に移動させる移動手段と、前記放電電極を前記放電電極
が前記被加工物に近づく方向に移動させ、前記検出手段
が前記短絡状態を検出したとき、前記放電電極が前記被
加工物から離れる方向に移動させるように前記移動手段
を制御する制御手段とを備えたことを特徴とする放電加
工装置を提供する。本発明は、上記目的を達成するた
め、放電電極を所定の加工速度で被加工物に対して相対
的に移動させつつ、コンデンサ放電回路により前記放電
電極と前記被加工物との間で所定の周期で放電させて前
記被加工物を放電加工する放電加工装置において、前記
放電電極と前記被加工物との間の放電開始状態、および
前記所定の周期毎に前記放電電極と前記被加工物との間
の短絡状態の有無を検出する検出手段と、前記放電電極
を前記所定の加工速度、あるいは前記所定の加工速度よ
り高速の移動速度で前記放電電極が前記被加工物に近づ
く方向に前記被加工物に対して相対的に移動させ、また
は前記放電電極を前記放電電極が前記被加工物から離れ
る方向に相対的に移動させる移動手段と、前記放電電極
を前記高速の移動速度で前記放電電極が前記被加工物に
近づく方向に移動させ、前記検出手段が前記放電開始状
態を検出したとき、前記放電電極を前記加工速度で移動
させ、前記検出手段が前記短絡状態を検出したとき、前
記放電電極が前記被加工物から離れる方向に移動させる
ように前記移動手段を制御する制御手段とを備えたこと
を特徴とする放電加工装置を提供する。本発明は、上記
目的を達成するため、コンデンサ放電回路により前記放
電電極と前記被加工物との間で所定の周期で放電させて
前記被加工物を放電加工する放電加工装置において、前
記放電電極と前記被加工物との間の短絡時の電流値以
上、放電加工時のピーク電流値以下に第１の閾値が設定
され、前記放電電極と前記被加工物との間に流れる電流
波形の最大値が前記第１の閾値を越えたことによって前
記放電電極と前記被加工物との間の放電開始状態を検出
するとともに、前記放電電極と前記被加工物との間の短
絡時の電流値以下に第２の閾値が設定され、前記所定の
周期毎に前記放電電極と前記被加工物との間に流れる電
流の前記所定の周期における平均値が前記第２の閾値を
越えたか否かを判断し、前記第２の閾値を超えたことに
よって前記放電電極と前記被加工物との間の短絡状態を
検出する放電状態検出手段を備えたことを特徴とする放
電加工装置を提供する。本発明は、上記目的を達成する
ため、コンデンサ放電回路により前記放電電極と前記被
加工物との間で所定の周期で放電させて前記被加工物を
放電加工する放電加工装置において、放電加工時の電圧
値以上、放電直前のピーク電圧値以下に閾値が設定さ
れ、前記放電電極と前記被加工物との間に生ずる電圧波
形の最大値が前記閾値を越えたことによって前記放電電
極と前記被加工物との間の放電開始状態を検出するとと
もに、前記所定の周期毎に前記放電電極と前記被加工物
との間に生ずる電圧が０になったか否かを判断し、０に
なったことによって前記放電電極と前記被加工物との間
の短絡状態を検出する放電状態検出手段を備えたことを
特徴とする放電加工装置を提供する。According to the present invention, in order to achieve the above object, the discharge electrode is moved by a capacitor discharge circuit while moving the discharge electrode relative to a workpiece at a predetermined machining speed. In the electric discharge machining method of performing electric discharge machining between the workpiece and the workpiece by performing electrical discharge machining, the discharge electrode moves in a direction in which the discharge electrode approaches the workpiece at a moving speed higher than the predetermined machining speed. The moving speed of the discharge electrode is switched to the predetermined machining speed when the electric motor is relatively moved with respect to the workpiece and a discharge start state between the discharge electrode and the workpiece is detected. Electrical discharge machining method. In order to achieve the above object, the present invention provides an electric discharge machining method for electric discharge machining of a workpiece by discharging at a predetermined period between a discharge electrode and a workpiece by a capacitor discharge circuit, wherein the discharge electrode is The discharge electrode is relatively moved with respect to the workpiece in a direction approaching the workpiece, and detects the presence or absence of a short circuit state between the discharge electrode and the workpiece at each predetermined cycle.
When the short-circuit state is detected, a discharge machining method is provided, wherein the discharge electrode is relatively moved with respect to the workpiece in a direction in which the discharge electrode is separated from the workpiece. In order to achieve the above object, the present invention provides a capacitor discharge circuit for moving a discharge electrode relative to a workpiece at a predetermined processing speed, and a predetermined distance between the discharge electrode and the workpiece by a capacitor discharge circuit. In the electric discharge machining method of performing electric discharge machining on the workpiece by discharging periodically, the discharge electrode is applied to the workpiece in a direction in which the discharge electrode approaches the workpiece at a moving speed higher than the predetermined machining speed. Relative to the workpiece, and when detecting a discharge start state between the discharge electrode and the workpiece, the moving speed of the discharge electrode is switched to the predetermined machining speed, and the moving speed of the discharge electrode is changed every predetermined cycle. Detecting the presence or absence of a short-circuit state between the discharge electrode and the workpiece, and detecting the short-circuit state, the discharge electrode with respect to the workpiece in a direction in which the discharge electrode is separated from the workpiece. Relatively moved To provide a discharge machining method comprising Rukoto. In order to achieve the above object, the present invention provides an electric discharge machining method for electric discharge machining of a workpiece by discharging a predetermined period between a discharge electrode and a workpiece by a capacitor discharge circuit, wherein the discharge electrode and the The first threshold value is set to be equal to or greater than the current value at the time of short circuit between the workpiece and the peak current value at the time of electrical discharge machining, and the maximum value of the current waveform flowing between the discharge electrode and the workpiece is A discharge start state between the discharge electrode and the workpiece is detected by exceeding the first threshold, and a second current value is set to be equal to or less than a current value at the time of a short circuit between the discharge electrode and the workpiece. The threshold value is set, and it is determined whether or not the average value of the current flowing between the discharge electrode and the workpiece in the predetermined cycle at each of the predetermined cycles has exceeded the second threshold value, As the second threshold value is exceeded, the discharge electrode and the To provide a discharge machining method characterized by detecting a short circuit condition between the engineering product. In order to achieve the above object, the present invention provides an electric discharge machining method for electric discharge machining of a workpiece by discharging a predetermined period between a discharge electrode and a workpiece by a capacitor discharge circuit, comprising the steps of: The threshold value is set to a value equal to or more than the peak voltage value immediately before the discharge, and the discharge electrode and the work piece are set when the maximum value of the voltage waveform generated between the discharge electrode and the work piece exceeds the threshold value. Between the discharge electrode and the workpiece is determined at each of the predetermined cycles to determine whether or not the voltage generated between the discharge electrode and the workpiece has become zero. There is provided an electric discharge machining method characterized by detecting a short-circuit state between an electrode and the workpiece. In order to achieve the above object, the present invention discharges a discharge between the discharge electrode and the workpiece by a capacitor discharge circuit while moving the discharge electrode relative to the workpiece at a predetermined processing speed. In the electric discharge machining apparatus for performing electric discharge machining of the workpiece, a detecting means for detecting a discharge start state between the discharge electrode and the workpiece, and the discharge electrode is connected to the predetermined machining speed or the predetermined A moving means for moving the discharge electrode relatively to the workpiece in a direction approaching the workpiece at a moving speed higher than a processing speed, and moving the discharge electrode at the high moving speed; When the detecting means detects the discharge start state, a control means for controlling the moving means so as to move the discharge electrode at the machining speed is provided. In order to achieve the above object, the present invention provides an electric discharge machine which discharges a workpiece between a workpiece and a discharge electrode at a predetermined cycle by a capacitor discharge circuit to perform electrical discharge machining on the workpiece. Detecting means for detecting the presence or absence of a short circuit state between the discharge electrode and the workpiece; and detecting the discharge electrode in a direction in which the discharge electrode approaches the workpiece, or the discharge electrode is connected to the workpiece. Moving means for relatively moving in a direction away from the workpiece, and moving the discharge electrode in a direction in which the discharge electrode approaches the workpiece, and when the detecting means detects the short-circuit state, the discharge electrode is connected to the workpiece. A control device for controlling the moving means so as to move the workpiece in a direction away from the workpiece is provided. In order to achieve the above object, the present invention provides a capacitor discharge circuit for moving a discharge electrode relative to a workpiece at a predetermined processing speed, and a predetermined distance between the discharge electrode and the workpiece by a capacitor discharge circuit. In a discharge machining apparatus that discharges at a period and discharge-machines the workpiece, a discharge start state between the discharge electrode and the workpiece, and the discharge electrode and the workpiece at every predetermined cycle. Detecting means for detecting the presence / absence of a short circuit state between the discharge electrode and the discharge electrode in a direction in which the discharge electrode approaches the workpiece at the predetermined processing speed or a moving speed higher than the predetermined processing speed. Moving means for moving the discharge electrode relatively to a workpiece or for moving the discharge electrode relatively in a direction in which the discharge electrode moves away from the workpiece; and moving the discharge electrode at the high moving speed. But When the detection means detects the discharge start state, the discharge electrode is moved at the processing speed, and when the detection means detects the short-circuit state, the discharge electrode is moved. And a control means for controlling the moving means so as to move the workpiece in a direction away from the workpiece. In order to achieve the above object, the present invention provides an electric discharge machining apparatus for electric discharge machining of a workpiece by discharging a predetermined cycle between the discharge electrode and the workpiece by a capacitor discharge circuit, The first threshold is set to be equal to or greater than the current value at the time of short circuit between the workpiece and the workpiece, and equal to or less than the peak current value at the time of electrical discharge machining, and the maximum of the current waveform flowing between the discharge electrode and the workpiece is set. When the value exceeds the first threshold value, a discharge start state between the discharge electrode and the workpiece is detected, and a current value at the time of a short circuit between the discharge electrode and the workpiece is equal to or less than a current value. A second threshold value is set, and it is determined whether or not an average value of a current flowing between the discharge electrode and the workpiece in the predetermined cycle exceeds the second threshold value in the predetermined cycle. And the second threshold is exceeded. To provide a discharge machining apparatus characterized by comprising a discharge state detecting means for detecting a short circuit condition between said workpiece and said discharge electrode. In order to achieve the above object, the present invention provides an electric discharge machine which discharges a predetermined period between the discharge electrode and the workpiece by a capacitor discharge circuit to discharge the workpiece. The threshold value is set to be equal to or higher than the voltage value of the discharge electrode and equal to or lower than the peak voltage value immediately before the discharge. When the maximum value of the voltage waveform generated between the discharge electrode and the workpiece exceeds the threshold value, the discharge electrode and the workpiece are Detecting the state of the start of discharge between the workpiece and the workpiece, and determining whether or not the voltage generated between the discharge electrode and the workpiece has become 0 at each of the predetermined cycles, And a discharge state detecting means for detecting a short-circuit state between the discharge electrode and the workpiece.

【０００６】[0006]

【発明の実施の形態】図１は、本発明の第１の実施の形
態に係る放電加工装置を示す。この放電加工装置１は、
放電加工用電極（以下「電極」と略す。）２と被加工物
３との間で放電させて被加工物３の微小領域を加工する
加工機４と、加工機４を制御する加工機制御部５と、電
極２と被加工物３との間に直流電圧を印加して放電させ
る放電加工回路６と、放電加工回路６上に設けられ、電
極２と被加工物３との間の放電波形を検出する電流プロ
ーブ７と、電流プローブ７から取り込んだ電流波形の緒
量の処理を行って放電波形データを出力する放電波形処
理部８と、放電波形処理部８からの放電波形データから
電極２と被加工物３との間の放電状態を判断し、その放
電状態に応じた信号を加工機制御部５に出力する放電開
始・短絡判断部９とを備える。FIG. 1 shows an electric discharge machining apparatus according to a first embodiment of the present invention. This electric discharge machine 1
A processing machine 4 that discharges between an electrode for electric discharge machining (hereinafter abbreviated as “electrode”) 2 and a workpiece 3 to process a minute area of the workpiece 3, and a processing machine control for controlling the processing machine 4. A discharge machining circuit 6 for applying a DC voltage between the electrode 2 and the workpiece 3 to discharge the battery, and a discharge between the electrode 2 and the workpiece 3 provided on the discharge machining circuit 6 A current probe 7 for detecting a waveform, a discharge waveform processing section 8 for processing the amount of the current waveform fetched from the current probe 7 and outputting discharge waveform data, and an electrode based on the discharge waveform data from the discharge waveform processing section 8 And a discharge start / short circuit judging section 9 for judging a discharge state between the workpiece 2 and the workpiece 3 and outputting a signal corresponding to the discharge state to the processing machine control section 5.

【０００７】装置本体４は、電極２を垂直方向Ｚに移動
させるＺ軸テーブル４０と、被加工物３を水平軸方向
Ｘ，Ｙに移動させるＸＹ軸テーブル４１と、加工槽４２
とを備える。The apparatus main body 4 includes a Z-axis table 40 for moving the electrode 2 in the vertical direction Z, an XY-axis table 41 for moving the workpiece 3 in the horizontal X and Y directions, and a processing tank 42.
And

【０００８】Ｚ軸テーブル４０は、垂直方向Ｚに移動す
るとともに、垂直方向Ｚを中心軸として回転するＺ軸４
０ａを備え、そのＺ軸４０ａの先端に、電極２が取り付
けられている。Ｚ軸テーブル４０およびＸＹ軸テーブル
４１は、移動速度が高速／低速の２段で切り替えできる
ようになっており、電極２を退避させるときは、高速で
垂直方向Ｚ上方に移動させるようになっている。加工槽
４２内は、絶縁性の加工液４３で満たされ、その加工液
４３中に被加工物３およびＸＹ軸テーブル４１が置かれ
る。The Z-axis table 40 moves in the vertical direction Z and rotates around the vertical direction Z as a center axis.
0a, and the electrode 2 is attached to the tip of the Z axis 40a. The Z-axis table 40 and the XY-axis table 41 are configured so that the moving speed can be switched between high speed and low speed. When the electrode 2 is retracted, the electrode 2 is moved upward in the vertical direction Z at high speed. I have. The inside of the processing tank 42 is filled with an insulating processing liquid 43, and the workpiece 3 and the XY-axis table 41 are placed in the processing liquid 43.

【０００９】加工機制御部５は、Ｚ軸テーブル４０およ
びＸＹ軸テーブル４１を制御して電極２および被加工物
３の移動量、移動方向、移動速度等の制御を行うもので
ある。The processing machine control section 5 controls the Z-axis table 40 and the XY-axis table 41 to control the moving amount, moving direction, moving speed, etc. of the electrode 2 and the workpiece 3.

【００１０】放電加工回路６は、通常のコンデンサ放電
回路であり、コンデンサ６０，抵抗６２，電源６２から
構成される。The electric discharge machining circuit 6 is a normal capacitor electric discharge circuit, and comprises a capacitor 60, a resistor 62 and a power supply 62.

【００１１】放電波形処理部８は、電極２あるいは被加
工物３の移動が開始されたとき、電極２と被加工物３の
間の放電電流波形を電流プローブ７によって取り込み、
その取り込んだ電流波形のうち放電パルス発生毎に一定
時間の電流波形の最大値と平均値を算出し、放電開始・
短絡判断部９に出力するものである。When the movement of the electrode 2 or the workpiece 3 is started, the discharge waveform processing section 8 captures the discharge current waveform between the electrode 2 and the workpiece 3 by the current probe 7,
The maximum value and average value of the current waveform for a certain period of time are calculated every time a discharge pulse is generated from the captured current waveform,
This is output to the short circuit judging unit 9.

【００１２】放電開始・短絡判断部９は、放電波形処理
部８による放電波形データから放電加工が開始された状
態（以下「放電開始状態」という。）、および電極２と
被加工物３とが接触した状態（以下「短絡状態」とい
う。）を判断し、各状態に応じた信号を加工機制御部５
に出力するものである。すなわち、放電開始・短絡判断
部９は、電極２と被加工物３との間の短絡時の電流値以
上、放電加工時のピーク電流値以下に第１の閾値が設定
され、電極２と被加工物３との間の短絡時の電流値以下
に第２の閾値が設定されており、放電波形処理部８から
の電流波形の最大値が第１の閾値を越えた場合に、放電
開始状態と判断し、放電開始状態を示す信号を加工機制
御部５に出力し、放電波形処理部８からの電流波形の平
均値が第２の閾値を越えた場合に、短絡状態と判断し、
短絡状態を示す信号を加工機制御部５に出力するように
構成されている。The discharge start / short circuit judging section 9 determines a state in which electric discharge machining has been started based on the discharge waveform data from the discharge waveform processing section 8 (hereinafter referred to as a “discharge start state”), and the electrode 2 and the workpiece 3. The contact state (hereinafter, referred to as “short-circuit state”) is determined, and a signal corresponding to each state is processed.
Is output to That is, the discharge start / short circuit judging unit 9 sets the first threshold to be equal to or more than the current value at the time of short circuit between the electrode 2 and the workpiece 3 and equal to or less than the peak current value at the time of electric discharge machining. When the second threshold value is set to be equal to or less than the current value at the time of short circuit with the workpiece 3 and the maximum value of the current waveform from the discharge waveform processing unit 8 exceeds the first threshold value, the discharge start state And outputs a signal indicating the discharge start state to the machine control unit 5. When the average value of the current waveform from the discharge waveform processing unit 8 exceeds the second threshold value, it is determined that a short circuit state has occurred.
It is configured to output a signal indicating a short-circuit state to the processing machine control unit 5.

【００１３】次に、本装置１の動作を図２(a) ，(b) お
よび図３を参照して説明する。Next, the operation of the apparatus 1 will be described with reference to FIGS. 2 (a) and 2 (b) and FIG.

【００１４】図２(a) ，(b) は、電流プローブ７が検出
した電流波形の一例を示す。なお、放電条件は、コンデ
ンサ６０の容量は２２０ｐＦ、抵抗６２は１ｋΩ、電源
６２の電圧は９０Ｖとした。ピーク電流値Ｉｐは、図２
(a) に示すように、約０．８Ａとなり、電極２と被加工
物３の間に接触が起こり、短絡状態となった場合に検出
される電流Ｉｓは、図２(b) に示すように、０．０９Ａ
である。この放電条件で放電加工を行う場合、放電開始
状態を検出するために、短絡時に検出される電流Ｉｓ＝
０．０９Ａ以上、放電加工時のピーク電流値Ｉｐ＝０．
８Ａ以下に第１の閾値９０を設定し、短絡状態を検出す
るために、０Ａ以上、短絡時の電流Ｉｓ＝０．０９Ａ以
下に第２の閾値９１を設定した。FIGS. 2A and 2B show an example of a current waveform detected by the current probe 7. FIG. The discharge conditions were as follows: the capacitance of the capacitor 60 was 220 pF, the resistance 62 was 1 kΩ, and the voltage of the power supply 62 was 90V. The peak current value Ip is shown in FIG.
As shown in FIG. 2A, the current Is is about 0.8 A, the contact between the electrode 2 and the workpiece 3 occurs, and the current Is detected when a short circuit occurs is obtained as shown in FIG. 0.09A
It is. When performing electric discharge machining under this electric discharge condition, in order to detect the electric discharge start state, the current Is detected at the time of short circuit is =
0.09 A or more, peak current value Ip = 0.
The first threshold value 90 was set to 8 A or less, and the second threshold value 91 was set to 0 A or more and the short-circuit current Is = 0.09 A or less to detect a short circuit state.

【００１５】図３は、本装置１の動作を示すフローチャ
ートである。なお、ここでは、電極２には超硬を、被加
工物３にはステンレス鋼（ＳＵＳ３０４）を用いた。電
極２の先端を直径５０μｍに加工し、被加工物３に穴加
工を行った。FIG. 3 is a flowchart showing the operation of the apparatus 1. Here, carbide was used for the electrode 2 and stainless steel (SUS304) was used for the workpiece 3. The tip of the electrode 2 was processed to a diameter of 50 μm, and a hole was formed in the workpiece 3.

【００１６】放電波形処理部８は、電極２もしくは被加
工物３の移動が開始された状態で、電極２と被加工物３
の間の放電電流波形を電流プローブ７によって取り込
む。放電波形処理部８は、取り込んだ電流波形のうち放
電パルス発生毎（ここでは約１ｋＨ）に一定時間（ここ
では約２μｓ）の電流波形の最大値と平均値を算出し、
放電開始・短絡判断部９に出力する。When the movement of the electrode 2 or the workpiece 3 is started, the discharge waveform processing section 8
Is taken in by the current probe 7. The discharge waveform processing unit 8 calculates the maximum value and the average value of the current waveform for a certain period of time (here, about 2 μs) each time a discharge pulse is generated (here, about 1 kHz) in the captured current waveform,
Output to the discharge start / short circuit determination unit 9.

【００１７】放電開始・短絡判断部９は、電流波形の最
大値が第１の閾値９０以下か否かを判断し（ＳＴ１）、
第１の閾値９０を越えている場合は、放電開始状態であ
ると判断し、その放電加工状態を示す信号を加工機制御
部５に出力する（ＳＴ２）。加工機制御部５は、放電開
始・短絡判断部９からの放電加工状態を示す信号に基づ
いて、ＸＹ軸テーブル４１およびＺ軸テーブル４０を制
御してＸＹ軸方向、Ｚ軸方向の移動速度を減速し、予め
設定されている加工時の電極２（あるいは被加工物３）
の移動速度（加工速度）に切り替える。The discharge start / short circuit judging section 9 judges whether or not the maximum value of the current waveform is equal to or less than the first threshold value 90 (ST1).
If it exceeds the first threshold value 90, it is determined that the electric discharge is started, and a signal indicating the electric discharge machining state is output to the machining control unit 5 (ST2). The machining machine control unit 5 controls the XY axis table 41 and the Z axis table 40 based on the signal indicating the electric discharge machining state from the electric discharge start / short circuit judging unit 9 to adjust the moving speed in the XY axis direction and the Z axis direction. Electrode 2 (or workpiece 3) at the time of processing, which is decelerated and set in advance
To the moving speed (processing speed).

【００１８】また、放電開始・短絡判断部９は、放電電
流波形の平均値が第２の閾値９１以上か否かを判断し
（ＳＴ３）、第２閾値９１を越えている場合は、短絡状
態であると判断し、その短絡状態を示す信号を加工機制
御部５に出力する（ＳＴ４）。加工機制御部５は、放電
開始・短絡判断部９からの短絡状態を示す信号に基づい
て、直ちに、電極２を鉛直方向Ｚ上方かつ被加工物３か
ら離す方向に移動させる退避動作を行う。加工機制御部
５は，放電開始・短絡判断部９から短絡状態を示す信号
が出力されなくなるまで、上記退避動作を継続させる。The discharge start / short circuit judging section 9 judges whether or not the average value of the discharge current waveform is equal to or larger than a second threshold value 91 (ST3). And outputs a signal indicating the short-circuit state to the processing machine control unit 5 (ST4). Based on the signal indicating the short-circuit state from the discharge start / short-circuit determination unit 9, the processing machine control unit 5 immediately performs a retreat operation for moving the electrode 2 upward in the vertical direction Z and away from the workpiece 3. The processing machine control unit 5 continues the evacuation operation until the signal indicating the short-circuit state is not output from the discharge start / short-circuit determination unit 9.

【００１９】電極２と被加工物３との間の短絡状態が回
避され、放電開始・短絡判断部９から加工機制御部５に
短絡状態を示す信号が出力されなくなった時点で、加工
機制御部５は、電極２を短絡が検出された位置へ移動さ
せる。短絡が検出された位置からの電極２（あるいは被
加工物３）の移動速度は、加工速度より高速で移動させ
る。短絡状態の回避後、電極２と被加工物３とが近づく
方向に電極２（あるいは被加工物３）を高速で移動さ
せ、放電加工状態を示す信号が放電開始・短絡判断部９
から加工機制御部５に出力された時点で減速し、予め設
定された加工速度に切り替える。When the short-circuit state between the electrode 2 and the workpiece 3 is avoided and the signal indicating the short-circuit state is no longer output from the discharge start / short-circuit determination section 9 to the processing machine control section 5, the processing machine control is stopped. The unit 5 moves the electrode 2 to a position where a short circuit is detected. The moving speed of the electrode 2 (or the workpiece 3) from the position where the short circuit is detected is moved faster than the processing speed. After avoiding the short circuit state, the electrode 2 (or the workpiece 3) is moved at a high speed in a direction in which the electrode 2 and the workpiece 3 approach each other, and a signal indicating the electric discharge machining state is output by the discharge start / short circuit judging unit 9
Is decelerated at the time when the processing speed is output to the processing machine control unit 5 and the processing speed is switched to a preset processing speed.

【００２０】以上のように加工を行い、放電開始状態お
よび短絡状態を示す信号が放電開始・短絡判断部９から
加工機制御部５へ入力されない状態が一定時間経過した
場合は（ＳＴ５）、加工を終了する。When machining is performed as described above, and a signal indicating a discharge start state and a short circuit state is not input from the discharge start / short circuit determination section 9 to the processing machine control section 5 for a predetermined time (ST5), machining is performed. To end.

【００２１】上述した第１の実施の形態によれば、放電
開始状態が検出されるまでは、電極２あるいは被加工物
３を高速の移動速度で移動させることができるので、放
電加工開始位置（加工位置）までの電極２あるいは被加
工物３の移動時間を短縮できる。また、放電開始状態お
よび短絡状態を瞬時に検出することが可能であるので、
放電加工時の速度をある程度高速にすることができるた
め、加工時間の短縮化が図れる。また、短絡状態を検出
したときは、電極２あるいは被加工物３を互いに離れる
方向に退避させているので、電極２と被加工物３との接
触による電極２の折損防止が可能になる。さらに、放電
開始状態および短絡状態を瞬時に検出することが可能で
あるので、微細な電極２を用いて微小領域を放電加工す
る場合でも、電極２の折損防止が可能になる。また、放
電エネルギーの小さいコンデンサ放電回路を用いている
ので、ミクロンオーダの微小領域の加工が可能になる。According to the above-described first embodiment, the electrode 2 or the workpiece 3 can be moved at a high moving speed until the discharge start state is detected. The moving time of the electrode 2 or the workpiece 3 to the processing position) can be reduced. Also, since the discharge start state and the short-circuit state can be detected instantaneously,
Since the speed during electric discharge machining can be increased to some extent, machining time can be reduced. Further, when the short-circuit state is detected, the electrode 2 or the workpiece 3 is retracted away from each other, so that the electrode 2 can be prevented from being broken due to the contact between the electrode 2 and the workpiece 3. Furthermore, since the discharge start state and the short-circuit state can be detected instantaneously, even when a minute area is subjected to electric discharge machining using the minute electrode 2, breakage of the electrode 2 can be prevented. Further, since a capacitor discharge circuit having a small discharge energy is used, it is possible to process a micro area on the order of microns.

【００２２】図４は、本発明の第２の実施の形態に係る
放電加工装置を示す。この放電加工装置１は、第１の実
施の形態の電流プローブ７の代わりに、電極２と被加工
物３との間に生ずる電圧波形を検出する電圧計１０を放
電加工回路６上に設けたものであり、電極２と被加工物
３との間で放電させて被加工物３の微小領域を加工する
加工機４と、加工機４を制御する加工機制御部５と、電
極２と被加工物３との間に直流電圧を印加して放電させ
る放電加工回路６と、電圧計１０から取り込んだ電圧波
形の緒量の処理を行って放電波形データを出力する放電
波形処理部８と、放電波形処理部８からの放電波形デー
タから電極２と被加工物３との間の放電状態を判断し、
その放電状態に応じた信号を加工機制御部５に出力する
放電開始・短絡判断部９とを備える。FIG. 4 shows an electric discharge machine according to a second embodiment of the present invention. In the electric discharge machining apparatus 1, a voltmeter 10 for detecting a voltage waveform generated between the electrode 2 and the workpiece 3 is provided on the electric discharge machining circuit 6, instead of the current probe 7 of the first embodiment. A processing machine 4 for processing a minute area of the workpiece 3 by discharging between the electrode 2 and the workpiece 3; a processing machine control unit 5 for controlling the processing machine 4; An electrical discharge machining circuit 6 for applying a DC voltage between the workpiece 3 and discharging, a discharge waveform processing unit 8 for performing processing of the amount of the voltage waveform fetched from the voltmeter 10 and outputting discharge waveform data, The discharge state between the electrode 2 and the workpiece 3 is determined from the discharge waveform data from the discharge waveform processing unit 8,
A discharge start / short circuit judging unit 9 for outputting a signal corresponding to the electric discharge state to the machining machine control unit 5 is provided.

【００２３】図５は、電圧計１０が検出した電圧波形の
一例を示す。放電開始・短絡判断部９は、放電加工時の
電圧値以上、放電加工時のピーク電圧値Ｖｐ以下であっ
てピーク電圧値Ｖｐ近傍に閾値９２が設定されており、
電極２と被加工物３との間に生ずる電圧波形の最大値が
閾値９２を越えた場合に、放電開始状態と判断し、放電
開始状態を示す信号を加工機制御部５に出力し、電極２
と被加工物３との間に生ずる電圧波形の平均値が０Ｖに
なった場合に、短絡状態と判断し、短絡状態を示す信号
を加工機制御部５に出力するように構成されている。FIG. 5 shows an example of a voltage waveform detected by the voltmeter 10. The discharge start / short circuit judging unit 9 sets the threshold value 92 at a value equal to or higher than the voltage value at the time of electric discharge machining, equal to or less than the peak voltage value Vp at the time of electric discharge machining and near the peak voltage value Vp
When the maximum value of the voltage waveform generated between the electrode 2 and the workpiece 3 exceeds the threshold value 92, it is determined that the discharge has started, and a signal indicating the discharge start state is output to the processing machine control unit 5; 2
When the average value of the voltage waveform generated between the workpiece and the workpiece 3 becomes 0 V, a short circuit state is determined, and a signal indicating the short circuit state is output to the processing machine control unit 5.

【００２４】上述した第２の実施の形態によれば、第１
の実施の形態と同様に、電極２と被加工物３との間の放
電開始状態および短絡状態を瞬時に検出することが可能
であるので、加工時間の短縮化が図れ、電極２の折損防
止が可能になる。また、放電エネルギーの小さいコンデ
ンサ放電回路を用いているので、ミクロンオーダの微小
領域の加工が可能になる。According to the second embodiment described above, the first
As in the first embodiment, since the discharge start state and the short-circuit state between the electrode 2 and the workpiece 3 can be instantaneously detected, the machining time can be shortened and the electrode 2 can be prevented from being broken. Becomes possible. Further, since a capacitor discharge circuit having a small discharge energy is used, it is possible to process a micro area on the order of microns.

【００２５】[0025]

【発明の効果】以上に説明した通り、本発明によれば、
放電開始状態が検出されるまで放電電極あるいは被加工
物を高速の移動速度で移動させることにより、放電加工
開始位置までの放電電極あるいは被加工物の移動時間を
短縮できるので、加工時間の短縮化が図れる。また、放
電が発生する毎に短絡状態を有無を判断し、短絡状態を
検出したとき、放電電極あるいは被加工物を互いに離れ
る方向に退避させることにより、放電電極の折損を防止
することが可能になる。また、放電エネルギーの小さい
コンデンサ放電回路を用いているので、ミクロンオーダ
の微小領域の加工が可能になる。As described above, according to the present invention,
By moving the discharge electrode or the workpiece at a high speed until the discharge start state is detected, the travel time of the discharge electrode or the workpiece to the start position of the electrical discharge machining can be shortened. Can be achieved. In addition, it is possible to prevent breakage of the discharge electrode by retreating the discharge electrode or the workpiece in a direction away from each other when the presence or absence of the short circuit is determined every time a discharge occurs and the short circuit state is detected. Become. Further, since a capacitor discharge circuit having a small discharge energy is used, it is possible to process a micro area on the order of microns.

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

【図１】本発明の第１の実施の形態に係る放電加工装置
の概略構成図である。FIG. 1 is a schematic configuration diagram of an electric discharge machine according to a first embodiment of the present invention.

【図２】(a) は第１の実施の形態に係る放電加工装置の
放電加工時の放電電流波形を示す図、(b) は第１の実施
の形態に係る放電加工装置の短絡時の放電電流波形を示
す図である。2A is a diagram showing a discharge current waveform at the time of electric discharge machining of the electric discharge machine according to the first embodiment, and FIG. 2B is a diagram showing a discharge current waveform at the time of short circuit of the electric discharge machine according to the first embodiment. It is a figure showing a discharge current waveform.

【図３】第１の実施の形態に係る放電加工装置の動作を
示すフローチャートである。FIG. 3 is a flowchart showing an operation of the electric discharge machine according to the first embodiment.

【図４】本発明の第２の実施の形態に係る放電加工装置
の概略構成図である。FIG. 4 is a schematic configuration diagram of an electric discharge machine according to a second embodiment of the present invention.

【図５】第２の実施の形態に係る放電加工装置の放電加
工時の放電電圧波形を示す図である。FIG. 5 is a diagram showing a discharge voltage waveform at the time of electric discharge machining of the electric discharge machine according to the second embodiment.

【符号の説明】[Explanation of symbols]

１放電加工装置２被加工物３放電加工用電極４加工機５加工機制御部６放電加工回路７電流プローブ８放電波形処理部９放電開始・短絡判断部１０電圧計４０Ｚ軸テーブル４０ａＺ軸４１ＸＹ軸テーブル４２加工槽４３加工液６０コンデンサ６１抵抗６２電源９０第１の閾値９１第２の閾値Ｉｐピーク電流値Ｖｐピーク電圧値 REFERENCE SIGNS LIST 1 electric discharge machining device 2 workpiece 3 electric discharge machining electrode 4 processing machine 5 processing machine control unit 6 electric discharge machining circuit 7 current probe 8 discharge waveform processing unit 9 discharge start / short circuit judgment unit 10 voltmeter 40 Z axis table 40a Z axis 41 XY-axis table 42 Working tank 43 Working fluid 60 Capacitor 61 Resistance 62 Power supply 90 First threshold 91 Second threshold Ip Peak current value Vp Peak voltage value

───────────────────────────────────────────────────── フロントページの続き (72)発明者鈴木良雄神奈川県足柄上郡中井町境430 グリーンテクなかい富士ゼロックス株式会社内 ──────────────────────────────────────────────────続き Continuing on the front page (72) Inventor Yoshio Suzuki 430 Sakai Nakai-cho, Ashigarakami-gun, Kanagawa Prefecture Green Tech Nakai Fuji Xerox Co., Ltd.

Claims

【特許請求の範囲】[Claims]

【請求項１】放電電極を所定の加工速度で被加工物に対
して相対的に移動させつつ、コンデンサ放電回路により
前記放電電極と前記被加工物との間で放電させて前記被
加工物を放電加工する放電加工方法において、前記放電電極を前記所定の加工速度より高速の移動速度
で前記放電電極が前記被加工物に近づく方向に前記被加
工物に対して相対的に移動させ、前記放電電極と前記被加工物との間の放電開始状態を検
出したとき、前記放電電極の移動速度を前記所定の加工
速度に切り替えることを特徴とする放電加工方法。An electric discharge is performed between a discharge electrode and the workpiece by a capacitor discharge circuit while moving the discharge electrode relative to the workpiece at a predetermined machining speed, thereby causing the workpiece to be discharged. In the electric discharge machining method for performing electric discharge machining, the electric discharge electrode is relatively moved with respect to the workpiece in a direction in which the discharge electrode approaches the workpiece at a moving speed higher than the predetermined machining speed; An electric discharge machining method, wherein when a discharge start state between an electrode and the workpiece is detected, a moving speed of the discharge electrode is switched to the predetermined machining speed.

【請求項２】前記放電開始状態の検出は、前記放電電極
と前記被加工物との間の短絡時の電流値以上、放電加工
時のピーク電流値以下に閾値を設定し、前記放電電極と
前記被加工物との間に流れる電流波形の最大値が前記閾
値を越えたことによって行う構成の請求項１記載の放電
加工方法。2. The method according to claim 1, wherein a threshold value is set to a value equal to or greater than a current value during a short circuit between the discharge electrode and the workpiece and equal to or less than a peak current value during electrical discharge machining. 2. The electric discharge machining method according to claim 1, wherein the electric discharge machining method is performed when a maximum value of a current waveform flowing between the workpiece and the workpiece exceeds the threshold.

【請求項３】前記放電開始状態の検出は、放電加工時の
電圧値以上、放電直前のピーク電圧値以下に閾値を設定
し、前記放電電極と前記被加工物との間に生ずる電圧波
形の最大値が前記閾値を越えたことによって行う構成の
請求項１記載の放電加工方法。3. A method for detecting a discharge start state, comprising setting a threshold value equal to or higher than a voltage value at the time of electric discharge machining and equal to or lower than a peak voltage value immediately before electric discharge, and determining a voltage waveform generated between the discharge electrode and the workpiece. 2. The electric discharge machining method according to claim 1, wherein the electric discharge machining is performed when a maximum value exceeds the threshold value.

【請求項４】コンデンサ放電回路により放電電極と被加
工物との間で所定の周期で放電させて前記被加工物を放
電加工する放電加工方法において、前記放電電極を前記放電電極が前記被加工物に近づく方
向に前記被加工物に対して相対的に移動させ、前記所定の周期毎に前記放電電極と前記被加工物との間
の短絡状態の有無を検出し、前記短絡状態を検出したと
き、前記放電電極を前記放電電極が前記被加工物から離
れる方向に前記被加工物に対して相対的に移動させるこ
とを特徴とする放電加工方法。4. An electric discharge machining method for electric discharge machining of a workpiece by discharging at a predetermined cycle between a discharge electrode and the workpiece by a capacitor discharge circuit, wherein the discharge electrode is formed by the discharge electrode. Moving relatively to the workpiece in a direction approaching the workpiece, detecting the presence or absence of a short-circuit state between the discharge electrode and the workpiece at the predetermined cycle, and detecting the short-circuit state And discharging the discharge electrode relative to the workpiece in a direction in which the discharge electrode moves away from the workpiece.

【請求項５】前記短絡状態の検出は、前記放電電極と前
記被加工物との間の短絡時の電流値以下に閾値を設定
し、前記放電電極と前記被加工物との間に流れる電流の
前記所定の周期における平均値が前記閾値を越えたこと
によって行う構成の請求項４記載の放電加工方法。5. A method for detecting a short circuit state, comprising setting a threshold value equal to or less than a current value at the time of a short circuit between the discharge electrode and the workpiece, and setting a current flowing between the discharge electrode and the workpiece. 5. The electric discharge machining method according to claim 4, wherein the electric discharge machining method is performed when an average value of the predetermined period exceeds the threshold value.

【請求項６】前記短絡状態の検出は、前記放電電極と前
記被加工物との間に生ずる電圧が０になったことによっ
て行う構成の請求項４記載の放電加工方法。6. The electric discharge machining method according to claim 4, wherein the detection of the short-circuit state is performed when a voltage generated between the discharge electrode and the workpiece becomes zero.

【請求項７】放電電極を所定の加工速度で被加工物に対
して相対的に移動させつつ、コンデンサ放電回路により
前記放電電極と前記被加工物との間で所定の周期で放電
させて前記被加工物を放電加工する放電加工方法におい
て、前記放電電極を前記所定の加工速度より高速の移動速度
で前記放電電極が前記被加工物に近づく方向に前記被加
工物に対して相対的に移動させ、前記放電電極と前記被加工物との間の放電開始状態を検
出したとき、前記放電電極の移動速度を前記所定の加工
速度に切り替え、前記所定の周期毎に前記放電電極と前記被加工物との間
の短絡状態の有無を検出し、前記短絡状態を検出したと
き、前記放電電極を前記放電電極が前記被加工物から離
れる方向に前記被加工物に対して相対的に移動させるこ
とを特徴とする放電加工方法。7. A capacitor discharge circuit discharges the discharge electrode between the discharge electrode and the workpiece at a predetermined cycle while moving the discharge electrode relative to the workpiece at a predetermined machining speed. In the electric discharge machining method for performing electric discharge machining on a workpiece, the discharge electrode is relatively moved with respect to the workpiece in a direction in which the discharge electrode approaches the workpiece at a moving speed higher than the predetermined machining speed. When detecting a discharge start state between the discharge electrode and the workpiece, the moving speed of the discharge electrode is switched to the predetermined machining speed, and the discharge electrode and the workpiece are switched at every predetermined cycle. Detecting the presence or absence of a short-circuit state with an object, and when detecting the short-circuit state, moving the discharge electrode relative to the workpiece in a direction in which the discharge electrode is separated from the workpiece. Characterized by Electrical processing method.

【請求項８】前記放電開始状態の検出は、前記放電電極
と前記被加工物との間の短絡時の電流値以上、放電加工
時のピーク電流値以下に第１の閾値を設定し、前記放電
電極と前記被加工物との間に流れる電流波形の最大値が
前記第１の閾値を越えたことによって行い、前記短絡状態の検出は、前記放電電極と前記被加工物と
の間の短絡時の電流値以下に第２の閾値を設定し、前記
放電電極と前記被加工物との間に流れる電流の前記所定
の周期における平均値が前記第２の閾値を越えたことに
よって行う構成の請求項７記載の放電加工方法。8. The detection of the discharge start state includes setting a first threshold value equal to or greater than a current value at the time of a short circuit between the discharge electrode and the workpiece and equal to or less than a peak current value at the time of electrical discharge machining. The detection is performed when the maximum value of the current waveform flowing between the discharge electrode and the workpiece exceeds the first threshold value. The short-circuit state is detected by detecting a short-circuit between the discharge electrode and the workpiece. The second threshold value is set to be equal to or less than the current value at the time, and the average value of the current flowing between the discharge electrode and the workpiece in the predetermined cycle exceeds the second threshold value. The electric discharge machining method according to claim 7.

【請求項９】前記放電開始状態の検出は、放電加工時の
電圧値以上、放電直前のピーク電圧値以下に閾値を設定
し、前記放電電極と前記被加工物との間に生ずる電圧波
形の最大値が前記閾値を越えたことによって行い、前記短絡状態の検出は、前記放電電極と前記被加工物と
の間に生ずる電圧が０になったことによって行う構成の
請求項７記載の放電加工方法。9. A method for detecting a discharge start state, comprising setting a threshold value equal to or higher than a voltage value at the time of electric discharge machining and equal to or lower than a peak voltage value immediately before electric discharge, and determining a voltage waveform generated between the discharge electrode and the workpiece. 8. The electric discharge machining according to claim 7, wherein the detection is performed when a maximum value exceeds the threshold value, and the short-circuit state is detected when a voltage generated between the discharge electrode and the workpiece becomes zero. Method.

【請求項１０】コンデンサ放電回路により放電電極と被
加工物との間で所定の周期で放電させて前記被加工物を
放電加工する放電加工方法において、前記放電電極と前記被加工物との間の短絡時の電流値以
上、放電加工時のピーク電流値以下に第１の閾値を設定
し、前記放電電極と前記被加工物との間に流れる電流波
形の最大値が前記第１の閾値を越えたことによって前記
放電電極と前記被加工物との間の放電開始状態を検出
し、前記放電電極と前記被加工物との間の短絡時の電流値以
下に第２の閾値を設定し、前記所定の周期毎に前記放電
電極と前記被加工物との間に流れる電流の前記所定の周
期における平均値が前記第２の閾値を越えたか否かを判
断し、前記第２の閾値を超えたことによって前記放電電
極と前記被加工物との間の短絡状態を検出することを特
徴とする放電加工方法。10. An electric discharge machining method for electric discharge machining of a workpiece by discharging a predetermined period between a discharge electrode and a workpiece by a capacitor discharge circuit, wherein a discharge between the discharge electrode and the workpiece is performed. The first threshold is set to be equal to or greater than the current value at the time of short circuit and equal to or less than the peak current value at the time of electric discharge machining, and the maximum value of the current waveform flowing between the discharge electrode and the workpiece is equal to the first threshold. Detecting a discharge start state between the discharge electrode and the workpiece by having exceeded, setting a second threshold below a current value at the time of short circuit between the discharge electrode and the workpiece, It is determined whether or not the average value of the current flowing between the discharge electrode and the workpiece in the predetermined cycle in each of the predetermined cycles exceeds the second threshold, and the average value of the current exceeding the second threshold is determined. Short circuit between the discharge electrode and the workpiece Discharge machining method characterized by detecting a state.

【請求項１１】コンデンサ放電回路により放電電極と被
加工物との間で所定の周期で放電させて前記被加工物を
放電加工する放電加工方法において、放電加工時の電圧値以上、放電直前のピーク電圧値以下
に閾値を設定し、前記放電電極と前記被加工物との間に
生ずる電圧波形の最大値が前記閾値を越えたことによっ
て前記放電電極と前記被加工物との間の放電開始状態を
検出し、前記所定の周期毎に前記放電電極と前記被加工物との間
に生ずる電圧が０になったか否かを判断し、０になった
ことによって前記放電電極と前記被加工物との間の短絡
状態を検出することを特徴とする放電加工方法。11. An electric discharge machining method for electric discharge machining of a workpiece by discharging a predetermined period between a discharge electrode and a workpiece by a capacitor discharge circuit, comprising the steps of: A threshold value is set below the peak voltage value, and the discharge between the discharge electrode and the workpiece starts when the maximum value of the voltage waveform generated between the discharge electrode and the workpiece exceeds the threshold value. A state is detected, and it is determined whether or not a voltage generated between the discharge electrode and the workpiece becomes 0 at each of the predetermined cycles. When the voltage becomes 0, the discharge electrode and the workpiece are determined. An electric discharge machining method characterized by detecting a short-circuit state between the electric discharge machining and the electric discharge machining.

【請求項１２】放電電極を所定の加工速度で被加工物に
対して相対的に移動させつつ、コンデンサ放電回路によ
り前記放電電極と前記被加工物との間で放電させて前記
被加工物を放電加工する放電加工装置において、前記放電電極と前記被加工物との間の放電開始状態を検
出する検出手段と、前記放電電極を前記所定の加工速度、あるいは前記所定
の加工速度より高速の移動速度で前記放電電極が前記被
加工物に近づく方向に前記被加工物に対して相対的に移
動させる移動手段と、前記放電電極を前記高速の移動速度で移動させ、前記検
出手段が前記放電開始状態を検出したとき、前記放電電
極を前記加工速度で移動させるよう前記移動手段を制御
する制御手段とを備えたことを特徴とする放電加工装
置。12. A workpiece is discharged by a capacitor discharge circuit between the discharge electrode and the workpiece while the discharge electrode is relatively moved with respect to the workpiece at a predetermined machining speed. In an electric discharge machine for performing electric discharge machining, a detecting means for detecting a discharge start state between the discharge electrode and the workpiece, and moving the discharge electrode at the predetermined machining speed or at a speed higher than the predetermined machining speed. Moving means for moving the discharge electrode relative to the workpiece in a direction in which the discharge electrode approaches the workpiece at a speed; and moving the discharge electrode at the high moving speed; And a control means for controlling the moving means so as to move the discharge electrode at the machining speed when a state is detected.

【請求項１３】前記検出手段は、前記放電電極と前記被
加工物との間の短絡時の電流値以上、放電加工時のピー
ク電流値以下に閾値が設定され、前記放電電極と前記被
加工物との間に流れる電流波形の最大値が前記閾値を越
えたことによって前記放電開始状態を検出する構成の請
求項１２記載の放電加工装置。13. The detecting means according to claim 1, wherein a threshold value is set to a value equal to or greater than a current value at the time of a short circuit between said discharge electrode and said workpiece and equal to or less than a peak current value at a time of electrical discharge machining. 13. The electric discharge machining apparatus according to claim 12, wherein the electric discharge start state is detected when a maximum value of a current waveform flowing between the electric discharge object and the object exceeds the threshold value.

【請求項１４】前記検出手段は、放電加工時の電圧値以
上、放電直前のピーク電圧値以下に閾値が設定され、前
記放電電極と前記被加工物との間に生ずる電圧波形の最
大値が前記閾値を越えたことによって前記放電開始状態
を検出する構成の請求項１２記載の放電加工装置。14. A threshold value is set to a value equal to or higher than a voltage value at the time of electric discharge machining and equal to or lower than a peak voltage value immediately before electric discharge, and a maximum value of a voltage waveform generated between the discharge electrode and the workpiece is set. 13. The electric discharge machining apparatus according to claim 12, wherein the electric discharge start state is detected by exceeding the threshold.

【請求項１５】コンデンサ放電回路により被加工物と放
電電極との間で所定の周期で放電させて前記被加工物を
放電加工する放電加工装置において、前記所定の周期毎に前記放電電極と前記被加工物との間
の短絡状態の有無を検出する検出手段と、前記放電電極を、前記放電電極が前記被加工物に近づく
方向、あるいは前記放電電極が前記被加工物から離れる
方向に相対的に移動させる移動手段と、前記放電電極を前記放電電極が前記被加工物に近づく方
向に移動させ、前記検出手段が前記短絡状態を検出した
とき、前記放電電極が前記被加工物から離れる方向に移
動させるように前記移動手段を制御する制御手段とを備
えたことを特徴とする放電加工装置。15. An electric discharge machining apparatus for electric discharge machining of a workpiece by discharging a workpiece between a workpiece and a discharge electrode at a predetermined cycle by a capacitor discharge circuit, wherein the discharge electrode and the discharge electrode are provided at every predetermined cycle. Detecting means for detecting the presence or absence of a short-circuit state between the workpiece and the workpiece; and relative to the discharge electrode in a direction in which the discharge electrode approaches the workpiece or in a direction in which the discharge electrode moves away from the workpiece. Moving means for moving the discharge electrode in a direction in which the discharge electrode approaches the work piece, and when the detection means detects the short-circuit state, the discharge electrode moves in a direction away from the work piece. A control unit for controlling the moving unit so as to move the electric discharge machining unit.

【請求項１６】前記検出手段は、前記放電電極と前記被
加工物との間の短絡時の電流値以下に閾値を設定し、前
記放電電極と前記被加工物との間に流れる電流の前記所
定の周期における平均値が前記閾値を越えた場合に、前
記短絡状態を検出する構成の請求項１５記載の放電加工
装置。16. The detecting means sets a threshold value equal to or less than a current value when a short circuit occurs between the discharge electrode and the workpiece, and sets a threshold value of a current flowing between the discharge electrode and the workpiece. 16. The electric discharge machining apparatus according to claim 15, wherein the short-circuit state is detected when an average value in a predetermined cycle exceeds the threshold value.

【請求項１７】前記検出手段は、前記放電電極と前記被
加工物との間に生ずる電圧が０になった場合に、前記短
絡状態を検出する構成の請求項１５記載の放電加工装
置。17. The electric discharge machining apparatus according to claim 15, wherein said detecting means detects said short circuit state when a voltage generated between said discharge electrode and said workpiece becomes zero.

【請求項１８】放電電極を所定の加工速度で被加工物に
対して相対的に移動させつつ、コンデンサ放電回路によ
り前記放電電極と前記被加工物との間で所定の周期で放
電させて前記被加工物を放電加工する放電加工装置にお
いて、前記放電電極と前記被加工物との間の放電開始状態、お
よび前記所定の周期毎に前記放電電極と前記被加工物と
の間の短絡状態の有無を検出する検出手段と、前記放電電極を前記所定の加工速度、あるいは前記所定
の加工速度より高速の移動速度で前記放電電極が前記被
加工物に近づく方向に前記被加工物に対して相対的に移
動させ、または前記放電電極を前記放電電極が前記被加
工物から離れる方向に相対的に移動させる移動手段と、前記放電電極を前記高速の移動速度で前記放電電極が前
記被加工物に近づく方向に移動させ、前記検出手段が前
記放電開始状態を検出したとき、前記放電電極を前記加
工速度で移動させ、前記検出手段が前記短絡状態を検出
したとき、前記放電電極が前記被加工物から離れる方向
に移動させるように前記移動手段を制御する制御手段と
を備えたことを特徴とする放電加工装置。18. A method of discharging a discharge electrode at a predetermined cycle between a discharge electrode and the workpiece by a capacitor discharge circuit while moving the discharge electrode relative to the workpiece at a predetermined processing speed. In an electric discharge machining apparatus for performing electric discharge machining of a workpiece, a discharge start state between the discharge electrode and the workpiece, and a short-circuit state between the discharge electrode and the workpiece at each predetermined cycle. Detecting means for detecting the presence or absence of the discharge electrode relative to the workpiece in the direction in which the discharge electrode approaches the workpiece at the predetermined processing speed, or at a moving speed higher than the predetermined processing speed; Moving means for moving the discharge electrode relatively or in a direction in which the discharge electrode moves away from the workpiece; and the discharge electrode moving the discharge electrode at the high-speed moving speed to the workpiece. Approaching When the detection means detects the discharge start state, the discharge electrode is moved at the machining speed, and when the detection means detects the short-circuit state, the discharge electrode is moved from the workpiece. Control means for controlling the moving means so as to move in a direction away from the electric discharge machining apparatus.

【請求項１９】前記検出手段は、前記放電電極と前記被
加工物との間の短絡時の電流値以上、放電加工時のピー
ク電流値以下に第１の閾値が設定され、前記放電電極と
前記被加工物との間の短絡時の電流値以下に第２の閾値
が設定され、前記放電電極と前記被加工物との間に流れ
る電流波形の最大値が前記第１の閾値を越えた場合に、
前記放電開始状態を検出し、前記放電電極と前記被加工
物との間に流れる電流の前記所定の周期における平均値
が前記第２の閾値を越えた場合に、前記短絡状態を検出
する構成の請求項１８記載の放電加工装置。19. The detecting means according to claim 1, wherein a first threshold is set to a value equal to or more than a current value at the time of short circuit between the discharge electrode and the workpiece and equal to or less than a peak current value at the time of electric discharge machining. A second threshold value is set to be equal to or less than a current value at the time of short circuit between the workpiece and the maximum value of a current waveform flowing between the discharge electrode and the workpiece exceeds the first threshold value. In case,
Detecting the discharge start state, and detecting the short-circuit state when an average value of a current flowing between the discharge electrode and the workpiece in the predetermined cycle exceeds the second threshold value. An electric discharge machine according to claim 18.

【請求項２０】前記検出手段は、放電加工時の電圧値以
上、放電直前のピーク電圧値以下に閾値が設定され、前
記放電電極と前記被加工物との間に生ずる電圧波形の最
大値が前記閾値を越えた場合に、前記放電開始状態を検
出し、前記放電電極と前記被加工物との間に生ずる電圧
が０になった場合に、前記短絡状態を検出する構成の請
求項１８記載の放電加工装置。20. The detecting means, wherein a threshold value is set to a value equal to or higher than a voltage value at the time of electric discharge machining and equal to or lower than a peak voltage value immediately before electric discharge. 19. The configuration according to claim 18, wherein when the threshold value is exceeded, the discharge start state is detected, and when the voltage generated between the discharge electrode and the workpiece becomes zero, the short-circuit state is detected. EDM equipment.

【請求項２１】コンデンサ放電回路により前記放電電極
と前記被加工物との間で所定の周期で放電させて前記被
加工物を放電加工する放電加工装置において、前記放電電極と前記被加工物との間の短絡時の電流値以
上、放電加工時のピーク電流値以下に第１の閾値が設定
され、前記放電電極と前記被加工物との間に流れる電流
波形の最大値が前記第１の閾値を越えたことによって前
記放電電極と前記被加工物との間の放電開始状態を検出
するとともに、前記放電電極と前記被加工物との間の短
絡時の電流値以下に第２の閾値が設定され、前記所定の
周期毎に前記放電電極と前記被加工物との間に流れる電
流の前記所定の周期における平均値が前記第２の閾値を
越えたか否かを判断し、前記第２の閾値を超えたことに
よって前記放電電極と前記被加工物との間の短絡状態を
検出する放電状態検出手段を備えたことを特徴とする放
電加工装置。21. An electric discharge machining apparatus for electric discharge machining of the workpiece by discharging a predetermined period between the discharge electrode and the workpiece by a capacitor discharge circuit, wherein the discharge electrode and the workpiece are The first threshold value is set to be equal to or greater than the current value at the time of short-circuiting and equal to or less than the peak current value at the time of electric discharge machining. By detecting the discharge start state between the discharge electrode and the workpiece by exceeding the threshold value, the second threshold value is equal to or less than the current value at the time of short circuit between the discharge electrode and the workpiece. It is determined whether or not the average value of the current flowing between the discharge electrode and the workpiece in the predetermined cycle has exceeded the second threshold value for each of the predetermined cycles, and The discharge electrode and the An electric discharge machining apparatus comprising: a discharge state detecting means for detecting a short-circuit state with a workpiece.

【請求項２２】コンデンサ放電回路により前記放電電極
と前記被加工物との間で所定の周期で放電させて前記被
加工物を放電加工する放電加工装置において、放電加工時の電圧値以上、放電直前のピーク電圧値以下
に閾値が設定され、前記放電電極と前記被加工物との間
に生ずる電圧波形の最大値が前記閾値を越えたことによ
って前記放電電極と前記被加工物との間の放電開始状態
を検出するとともに、前記所定の周期毎に前記放電電極
と前記被加工物との間に生ずる電圧が０になったか否か
を判断し、０になったことによって前記放電電極と前記
被加工物との間の短絡状態を検出する放電状態検出手段
を備えたことを特徴とする放電加工装置。22. An electric discharge machining apparatus for electric discharge machining of a workpiece by discharging a predetermined period between said discharge electrode and said workpiece by a capacitor discharge circuit. A threshold value is set below the immediately preceding peak voltage value, and the maximum value of the voltage waveform generated between the discharge electrode and the workpiece exceeds the threshold value. While detecting the discharge start state, it is determined whether or not the voltage generated between the discharge electrode and the workpiece has become 0 every predetermined cycle, and the discharge electrode and the An electric discharge machining apparatus comprising: a discharge state detecting means for detecting a short-circuit state with a workpiece.