JPS6034221A - Electric discharge machine - Google Patents
Electric discharge machineInfo
- Publication number
- JPS6034221A JPS6034221A JP14072383A JP14072383A JPS6034221A JP S6034221 A JPS6034221 A JP S6034221A JP 14072383 A JP14072383 A JP 14072383A JP 14072383 A JP14072383 A JP 14072383A JP S6034221 A JPS6034221 A JP S6034221A
- Authority
- JP
- Japan
- Prior art keywords
- gap
- output
- servo
- electric discharge
- workpiece
- 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.)
- Pending
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23H—WORKING OF METAL BY THE ACTION OF A HIGH CONCENTRATION OF ELECTRIC CURRENT ON A WORKPIECE USING AN ELECTRODE WHICH TAKES THE PLACE OF A TOOL; SUCH WORKING COMBINED WITH OTHER FORMS OF WORKING OF METAL
- B23H1/00—Electrical discharge machining, i.e. removing metal with a series of rapidly recurring electrical discharges between an electrode and a workpiece in the presence of a fluid dielectric
- B23H1/02—Electric circuits specially adapted therefor, e.g. power supply, control, preventing short circuits or other abnormal discharges
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Electrical Discharge Machining, Electrochemical Machining, And Combined Machining (AREA)
Abstract
Description
【発明の詳細な説明】
本発明は放電加工装置、特に電極と被加工物と(1)
を絶縁性加工液を介在させて対向させ、その極間間隙内
に放電を発生させて上記被加工物を加工する放電加工装
置に関するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electric discharge machining apparatus, in particular, an electrode and a workpiece (1) are faced to each other with an insulating machining liquid interposed therebetween, and an electric discharge is generated in the gap between the electrodes to machine the workpiece. This invention relates to electrical discharge machining equipment for machining objects.
第1図には従来の放電加工装置の概要構成図が示されて
いる。第1図において、電8iiioは加工槽12内に
置かれた被加工物14と絶縁性加工液16を介して対向
している。電極10と被加工物14間には加工電源18
が接続されている。この加工電源18は直流型1lti
18 aと、加工電流の断続を行なうためのスイッチン
グ素子18bと、電流制限抵抗18cと、上記スイッチ
ング素子18bの断続を制御するための発振器18dと
によって構成され、加工電流を断続的に電$1i10と
被加工物14との極間間隙20に供給する。FIG. 1 shows a schematic configuration diagram of a conventional electric discharge machining apparatus. In FIG. 1, the electric current 8iiio faces a workpiece 14 placed in a processing tank 12 with an insulating processing liquid 16 interposed therebetween. A processing power source 18 is connected between the electrode 10 and the workpiece 14.
is connected. This processing power supply 18 is a DC type 1lti
18a, a switching element 18b for on/off of the machining current, a current limiting resistor 18c, and an oscillator 18d for controlling the on/off of the switching element 18b. It is supplied to the gap 20 between the poles and the workpiece 14.
上記の加工電流lは、■= 亘(Eは直流型源18aの
電圧値、Rは電流制限抵抗18cの抵抗値、vgは極間
電圧値)の式であられされる。極間電圧値v9は、アー
ク放電中は20〜30v1短絡時はOv1無放電中はE
Vとなり、スイッチング素子IBbがオフ状態の時はO
vとなる。The above-mentioned machining current l is expressed by the following formula: ■=Wataru (E is the voltage value of the DC type source 18a, R is the resistance value of the current limiting resistor 18c, and vg is the voltage between electrodes). The voltage between electrodes v9 is 20 to 30v during arc discharge, Ov during short circuit, and E during no discharge.
V, and O when switching element IBb is off.
It becomes v.
(2)
そこでこの極間電圧値vgを検出して平滑回路22で平
均化すれば、この値で極間間隙制御を行なうことができ
る。すなわち、極間間隙20が広い時は放電が起りにく
く平均電圧値Vsは高い。極間間隙20が狭い時は短絡
したり、容易に放電するため平均電圧値Vsは低下する
。従って、この平均電圧値Vsを基準電圧値Vtと比較
して、この差を増幅N24で増幅して油圧サーボコイル
26に入力すれば、油圧発生ポンプ28と油圧シリンダ
30とで構成される油圧サーボ機構によって、極間間l
I20がほぼ一定になるように電極10を制御する乙と
ができる。(2) Therefore, if this inter-electrode voltage value vg is detected and averaged by the smoothing circuit 22, the inter-electrode gap can be controlled using this value. That is, when the inter-electrode gap 20 is wide, discharge is difficult to occur and the average voltage value Vs is high. When the inter-electrode gap 20 is narrow, short circuits or discharges occur easily, resulting in a decrease in the average voltage value Vs. Therefore, if this average voltage value Vs is compared with the reference voltage value Vt and this difference is amplified by the amplification N24 and inputted to the hydraulic servo coil 26, the hydraulic servo coil composed of the hydraulic pressure generation pump 28 and the hydraulic cylinder 30 Depending on the mechanism, the distance between poles l
The electrode 10 can be controlled so that I20 is approximately constant.
従来の放電加工装置で加工状態の良否を判別する際、最
も一般的なのlま上記の極間電圧値v9の平均電圧値V
sele!測することである。すなわち、平均電圧値V
sが低い時は極間インピーダンスが低い場合であって、
短絡、連続的アーク放電となり、極間間隙20には加工
粉やスラッジの滞留等が考えられる。しかし放電加工に
おいて最も危険な異常アーク放電は、一度発生すると加
工液の熱分解(3)
によるカーボン発生のために、カーボンと被加工物との
間の放電となり、極間インピーダンスが高くなったよう
な状態になる。乙のため平均電圧値Vsの111nでは
異常アーク放電による極間間隙状態悪化の検出は不可能
であるという欠点があった。When determining whether the machining state is good or bad with a conventional electric discharge machining device, the most common method is the average voltage value V of the above machining voltage value v9.
sele! It is to measure. That is, the average voltage value V
When s is low, the impedance between poles is low,
Short circuits and continuous arc discharge may occur, and machining powder and sludge may remain in the gap 20 between the poles. However, the most dangerous abnormal arc discharge in electric discharge machining is that once it occurs, carbon is generated due to thermal decomposition of the machining fluid (3), resulting in an electric discharge between the carbon and the workpiece, and the impedance between the electrodes increases. It becomes a state. Therefore, there was a drawback that it was impossible to detect deterioration of the inter-electrode gap condition due to abnormal arc discharge at the average voltage value Vs of 111n.
本発明は前述した従来の課題に鑑み為されたものであり
、その目的は放電発生時の極間間隙放電電圧波形の周波
数スペクトル解析を行って正常放電と異常放電の判別を
し極間間隙状態が正常となるように極間間隙サーボのた
めのサーボ機構のサーボゲインを制御する乙とにより、
適切な極間開離と接近速度を得るようにした放電加工装
置を提供することにある。The present invention has been made in view of the above-mentioned conventional problems, and its purpose is to analyze the frequency spectrum of the discharge voltage waveform of the gap between electrodes when a discharge occurs, to distinguish between normal discharge and abnormal discharge, and to determine the state of the gap between electrodes. By controlling the servo gain of the servo mechanism for the pole gap servo so that the
It is an object of the present invention to provide an electric discharge machining apparatus which can obtain appropriate machining distance and approach speed.
上記目的を達成するために、本発明は電極と被加工物と
を絶縁性加工液を介在させて対向させ、その対向間隙内
に放電を発生させて上記被加工物を加工する放電加工装
置において、電極と被加工物の間の放電電圧波形の周波
数スペクトルを分析し、異常放電状態と正常放電状態で
あるかを識別する異常放電検出手段と、上記分析によっ
て極間(4)
間隙状態に応じて信号を出力する極間状態判別手段と、
この判別手段の出力に基ずいて極間間隙サーボのサーボ
ゲインを制御する制御手段とを備えたことを特徴とする
。In order to achieve the above object, the present invention provides an electric discharge machining apparatus that machines the workpiece by arranging an electrode and a workpiece to face each other with an insulating machining liquid interposed therebetween, and generating electric discharge in the opposing gap. , an abnormal discharge detection means that analyzes the frequency spectrum of the discharge voltage waveform between the electrode and the workpiece and identifies whether it is an abnormal discharge state or a normal discharge state; an interpolation state determining means for outputting a signal;
The present invention is characterized by comprising a control means for controlling the servo gain of the pole gap servo based on the output of the discrimination means.
以下、図面に基づいて本発明の好適な実施例を説明する
。第2図は本発明における検出原理を説明するための放
電電圧波形と、その周波数スペクトルを示すものであっ
て、無放電の際のように放電せずに単なる電圧パルスの
印加のみの場合には比較的容易に数式化でき、ちなみに
振幅E2周期T、パルス輻τの時のスペクトルは以下に
ように表わすことができる。(しかし、放電波形の場合
アトランダムであり式化は難しい。)
第2図におけるスペクトル図はT=2τの場合を例にし
て記載した。このスペクトル分布と放電状態かられかる
ことは以下の項目である。Hereinafter, preferred embodiments of the present invention will be described based on the drawings. Figure 2 shows a discharge voltage waveform and its frequency spectrum to explain the detection principle in the present invention. It can be expressed relatively easily, and the spectrum when the amplitude is E2, the period is T, and the pulse intensity is τ can be expressed as follows. (However, in the case of a discharge waveform, it is at random and is difficult to formulate.) The spectrum diagram in FIG. 2 is described using the case of T=2τ as an example. The following items can be learned from this spectral distribution and discharge state.
(1)いづれの状態のスペクトルであっても、周期T(
5)
の逆数にあたる周波数f、に高い出力を示す。ただし正
常放電の場合、他と比較してそのピーク値は低い。(1) No matter which state the spectrum is in, the period T(
5) It shows high output at the frequency f, which is the reciprocal of . However, in the case of normal discharge, the peak value is low compared to others.
(2)1−りに関連するような放電の場合、高周波f1
.l(約2MH,以上)はほとんど存在せず正常放電の
場合200MH2付近にまで高周波成分が減衰しないで
発生している。(2) In the case of a discharge related to 1-ri, the high frequency f1
.. 1 (approximately 2 MH2 or more) hardly exists, and in the case of normal discharge, high frequency components are generated up to around 200 MH2 without attenuation.
+31 f、の時の出力が低く、fHでの出力が十分あ
れば正常放電しているとみなせる。If the output at +31 f is low and the output at fH is sufficient, it can be considered that normal discharge is occurring.
上記の結果より、(3)項のような状態にあることを判
別できれば放電状態の異常識別が可能となることがわか
る。From the above results, it can be seen that if it can be determined that the state described in item (3) is present, abnormality in the discharge state can be identified.
第3図は、この実施例を示す概要図であって、基本的に
は周波数スペクトル分析−と同様の構成となっている。FIG. 3 is a schematic diagram showing this embodiment, which basically has the same configuration as that of frequency spectrum analysis.
極間間隙の電圧信号F(t)は、FM変調M51の出力
信号f(t)と混合晋によって混合されヘテロダイン検
波によって、F(t)とf (t)の和の周波数のうち
中間周波j(tlの周波数のみが取り出され差も出るが
、これはフィルターによって除去する中間周波数増輻蕃
53により増幅され、検(6)
波藺54により振幅分が検波されて低周波増幅器55に
よって増幅されろ。前述のFM変調l#51は、アナロ
グ電圧AVによって周波数変調されているので、このア
ナログ電圧^νを時間に比例して変化させることにより
時間と周波数の関係が直線的となり、時間毎にF(tl
のうちのj (t)の周波数分多いだけの周波数スペク
トルの振幅を低周波増幅器55の出力として取り出すこ
とができる。よってアナログ電圧^νが前記のfo、f
Hに相当する電圧になる時間は正確な発振器56、及び
この出力を数えていくカウンター57によって判別でき
る。58はfoの判別器、59ばfI+の判別器である
。カウンター57の内容はD/A変I/i4響soによ
ってアナログ電圧AVとなり、前記FMlliFl@5
1を変調する。レベル比較N61はfの判別器あるいは
fi1判別器よりのタイミング信号に応答してそのタイ
ミングにおける所定の基準値よりも低周波増幅された振
幅、すなわち周波数スペクトルが大か小かの判別をし、
この結果に基づいて異常放電の時は出力84を出す。例
えばf、が3KH2,fHがSM&とする(7)
。また中間周波数10.7M)i、とすれば、f (t
)が、10.693MHzの時にfoが5.700 M
Hの時f、の各スペクトルが検出できる。FM変調讐5
1が広帯域のものであって、入力電圧Ovの時5MHz
、IOVの時10 M Hzのものとし、D/A変換が
16bj【タイプのものなら±80H2程度の分解能の
スペクトル分析器となる。また、■。に関しては常に加
工の条件選択の毎に変更されるので、、1丁
(ただし、周期Tはオンタイムとオフタイムの和)の演
算制御を行う必要がある。The voltage signal F(t) in the gap between the poles is mixed with the output signal f(t) of the FM modulation M51 by a mixing circuit, and by heterodyne detection, an intermediate frequency j is determined from the frequency of the sum of F(t) and f(t). (Only the frequency of tl is extracted and a difference is also produced, but this is amplified by an intermediate frequency amplifier 53 that is removed by a filter, and the amplitude component is detected by a detection (6) wave 54 and amplified by a low frequency amplifier 55. F.The above-mentioned FM modulation l#51 is frequency-modulated by the analog voltage AV, so by changing this analog voltage ^ν in proportion to time, the relationship between time and frequency becomes linear, and the F(tl
The amplitude of the frequency spectrum can be extracted as the output of the low frequency amplifier 55 by an amount corresponding to the frequency of j (t). Therefore, the analog voltage ^ν is the above fo, f
The time at which the voltage corresponds to H can be determined by an accurate oscillator 56 and a counter 57 that counts this output. 58 is a discriminator for fo, and 59 is a discriminator for fI+. The contents of the counter 57 become the analog voltage AV by the D/A change I/i4 sound, and the content of the counter 57 becomes the analog voltage AV by the D/A change
Modulate 1. The level comparison N61 responds to the timing signal from the f discriminator or the fi1 discriminator and determines whether the amplitude amplified at a lower frequency, that is, the frequency spectrum, is larger or smaller than a predetermined reference value at that timing,
Based on this result, an output 84 is output when abnormal discharge occurs. For example, let f be 3KH2 and fH be SM& (7). Also, if the intermediate frequency is 10.7M)i, then f (t
) is 10.693MHz, fo is 5.700M
When H, each spectrum of f can be detected. FM modulation 5
1 is a broadband one, and when the input voltage is Ov, it is 5MHz.
, IOV is 10 MHz, and if the D/A conversion is 16bj type, it will be a spectrum analyzer with a resolution of about ±80H2. Also ■. Since the parameters are always changed every time the machining conditions are selected, it is necessary to perform arithmetic control for one machine (however, the period T is the sum of the on-time and off-time).
さて、上記出力S^について、算4図のレベル比較器6
1の詳細説明図を用いてより詳しく説明する。低周波増
幅器55の出力はアナログスイッチ82.63により、
各々f、判別とf1判別のタイミング以外に比較@64
.65に接続されないようになっている。そして、’9
判別タイミングにおいて、スペクトル振幅voがvlよ
ゆ大であると比較器64の出力;よ“1″となし、AN
Dゲート66を介してカウンター67をカウントアツプ
する。また、f、1判別タイミングにおいて、上記■が
v2より111
大であると、比較965の出力は“1″となり、AND
ゲート68を介してカウンタ67をリセットするので、
このカウンター67はf0タイミングでのスペクトル振
幅大の時内春が増加し、fHタイミングでのvoが大の
時はただちにカウンタ内裏が零になる。よって高周波成
分があれば零% ’D酸成分大であると増加という状態
をくりかえすので、このカウンター内賽をD/A変換器
40を用いてアナログ電圧V、を観察することによって
も、極間間隙状態の良否を判別できる。すなわち、vo
が大であれば異常放電に近づいていることとなり、例え
ば加工粉の滞留によって極間間隙スラッジがたまってい
るとか、異常アークによって加工液16が熱分解してカ
ーボンが発生しているとか、電極の一部が破損してその
かけらが極間間隙20に存在するとか、等の不具合が容
易に検出できる。Now, regarding the above output S^, level comparator 6 in Figure 4
This will be explained in more detail using detailed explanatory diagram No. 1. The output of the low frequency amplifier 55 is output by an analog switch 82.63.
Compare each other than the timing of f, discrimination and f1 discrimination @64
.. 65 so that it is not connected. And '9
At the determination timing, if the spectrum amplitude vo is larger than vl, the output of the comparator 64 is determined to be "1", and AN
Counter 67 is counted up via D gate 66. In addition, at the f,1 determination timing, if the above ■ is 111 larger than v2, the output of the comparison 965 becomes "1", and the AND
Since the counter 67 is reset via the gate 68,
This counter 67 increases when the spectrum amplitude is large at f0 timing, and immediately becomes zero when vo is large at fH timing. Therefore, if there is a high frequency component, it will be 0%; if the acid component is large, it will increase. It is possible to determine whether the gap condition is good or bad. That is, vo
If it is large, it means that abnormal discharge is approaching.For example, sludge may have accumulated in the gap between the electrodes due to the retention of machining powder, or carbon may be generated due to thermal decomposition of the machining fluid 16 due to an abnormal arc. Problems such as a part of the electrode being damaged and a piece of it existing in the interpolar gap 20 can be easily detected.
しかしごく短時間であれば極間間隙状態は断えず変化し
ており、短時間前記のV、があっても必ずしも極間ll
I隙状態が悪いとは判断できない。そこでディジタルア
ナログ変換N40の出力馬の所定(9)
57
値以上の存在がある時間続いたことを検出して、極間間
隙状態の良否を判断する必要がある。However, in a very short period of time, the state of the gap between the poles is constantly changing, and even if the above-mentioned V exists for a short time, the gap between the poles does not always change.
It cannot be determined that the I-gap condition is bad. Therefore, it is necessary to detect whether the output value of the digital-to-analog conversion N40 exceeds a predetermined (9)57 value and continues for a certain period of time to judge whether the state of the gap between the poles is good or not.
第5図における電圧比較914Bはディジタルアナログ
変換@40の出力礪が所定値v11よりも大か小かを判
別している。V(1>V、、になると、電圧比較@l!
148の出力は負となり、ベース抵抗150を介してス
イッチング用トランジスタ152をオフ状態にする。こ
のため時間計測用コンデンサ154は抵抗156を介し
て充電され、コンデンサ154の両端電圧V31は次式
にようにあられされるただし、r2は抵抗156の抵抗
値
Cはコンデンサ154の容量
tは時間
このコンデンサ154の両端電圧3.は基準電圧−1と
電圧比較1Il1158で比較される。V、、>当の期
間は電圧比較響158の出力が負にならないため、発光
ダイオード16o;よ点灯しない。モしてv。A voltage comparison 914B in FIG. 5 determines whether the output voltage of the digital-to-analog conversion @40 is larger or smaller than a predetermined value v11. When V(1>V, , voltage comparison @l!
The output of 148 becomes negative, turning off switching transistor 152 via base resistor 150. Therefore, the time measuring capacitor 154 is charged via the resistor 156, and the voltage V31 across the capacitor 154 is expressed as follows. Voltage across the capacitor 1543. is compared with reference voltage -1 by voltage comparison 1Il1158. Since the output of the voltage comparator 158 does not become negative during this period, the light emitting diode 16o does not light up. Mote v.
(10)
〉vllの状態が所定時間継続してη/〉”21になる
と、電圧比較wr158の出力が負となり、発光ダイオ
ード160を抵抗162を介して点灯させて極間間隙状
態の異常発生を表示するものである。(10) When the state of 〉vll continues for a predetermined period of time and becomes η/〉”21, the output of the voltage comparison wr158 becomes negative, and the light emitting diode 160 is turned on via the resistor 162 to prevent abnormal occurrence of the gap between the electrodes. It is to be displayed.
スイッチ164は、時間の関数だけで極間間隙状態を判
断するか、ディジタルアナ四グ変換昭40の出力V、の
大きさと時間の積の関数として判断するかを切換えるた
めのスイッチである。すなわち単に時間だけの検出では
極間間隙状態の異常判別の困難な加工、例えば超硬合金
の加工のように一瞬にして1−りによる割れや、タング
ステンの欠落が発生する場合には、差の電圧と時間の積
の関数として、異常の発生をすみやかに知ることができ
る。すなわち短時間であっても、差が大であればコンデ
ンサCの充電電流が増え、ただちにコンデンサ電圧当が
v2に達するからである。The switch 164 is a switch for switching whether to judge the interpole gap state only as a function of time or as a function of the product of the magnitude of the output V of the digital analog/4G converter 1972 and time. In other words, in machining where it is difficult to determine abnormalities in the gap between the poles by simply detecting time, for example, in the machining of cemented carbide, where cracking due to one-hole or tungsten chipping occurs instantaneously, the difference can be detected. The occurrence of an abnormality can be quickly detected as a function of the product of voltage and time. That is, if the difference is large even for a short time, the charging current of the capacitor C will increase, and the capacitor voltage will immediately reach v2.
また、差の電圧当を直接電圧計で観測することより、最
適値と現在値の差を直接観測することができ、極間間隙
状態のモニターとして使用できることは明らかである。Furthermore, by directly observing the voltage difference with a voltmeter, it is possible to directly observe the difference between the optimum value and the current value, and it is clear that this can be used as a monitor for the state of the gap between the poles.
(11)
さて、上記検出回路によって得られた出力に基づいて極
間サーボのサーボゲインを変化させることにより、短絡
や開放状態、あるいはアークの前駆状態を回復させるこ
とができる。すなわち、上記のような悪い極間状態の場
合、サーボゲインを増加させ、間隙の開離と接近の速度
を増加させることにより、すみやかに機械的な悪い状態
からの廻避ができるようになり、極間状態を回復させる
ことができる。この実現のための一実施例を第6図を用
いて詳細に説明する。100は乗算型のディジタルアナ
ログ変換器で、上記カウンタ67の出力に従い入力アナ
ログ信号Vr−Vsに乗算した形式で出力できる素子で
あって、米国アナログデバイス社製のAD7520等が
公知である。すなわち、入力信号に対してボリュームの
働きをさせるものと考えればよい。該ボリュームの値が
上記検出回路の出力(ディジタル値)によって変化する
のである。よって本実例によれば、極間状態の悪化に従
ってサーボゲインが乗算型D/Aコンバータにより増加
し、抵抗102.103とオペアン(12)
プ104によって構成される増幅昭24を介してサーボ
バルブ26の制御コイルに入力され、サーボのアクチェ
ータの速度は増加する。本実施例では極間状態の悪さに
比例してほぼ直線的にサーボゲインを増加させているが
、必ずしも直線的に変化させる必要はなく、2次関数的
あるいは折れ線的変化によってもよい。上記検出信号S
Aを用い2段階の制御を行う等のほうが実施する場合容
易でかつ低価格に本発明の実施ができる。(11) Now, by changing the servo gain of the inter-pole servo based on the output obtained by the detection circuit, the short circuit, open state, or arc precursor state can be recovered. In other words, in the case of a bad gap condition like the one mentioned above, by increasing the servo gain and increasing the speed of opening and closing the gap, it is possible to quickly avoid the bad mechanical condition and improve the condition. It is possible to recover the temporary state. An embodiment for realizing this will be explained in detail using FIG. 6. Reference numeral 100 designates a multiplication type digital-to-analog converter, which is an element capable of outputting the result of multiplying the input analog signal Vr-Vs according to the output of the counter 67, and AD7520 manufactured by Analog Devices, Inc. in the United States is a well-known device. In other words, it can be thought of as having a volume function on the input signal. The value of the volume changes depending on the output (digital value) of the detection circuit. Therefore, according to this example, the servo gain is increased by the multiplier type D/A converter as the gap condition worsens, and the servo gain is increased by the multiplier type D/A converter, and the servo gain is increased by the servo valve 26 through the amplifier Sho 24 constituted by the resistors 102 and 103 and the operational amplifier (12) amplifier 104. control coil, and the speed of the servo's actuator increases. In this embodiment, the servo gain is increased almost linearly in proportion to the poorness of the inter-electrode condition, but it does not necessarily have to be changed linearly, and may be changed in a quadratic function or in a polygonal manner. The above detection signal S
It is easier to implement the present invention by performing two-stage control using A, and the present invention can be implemented at a lower cost.
なお実験によれば極間状態が悪化した時、少なくとも2
0−ノ分以上の速度がないと、アーク放電に移行し多量
の加工粉が極間に滞留した時は200++*/分程度の
速度が必要であることが判明した。また安定な加工の際
は、面粗度1.5μRmax以下の仕上加工において、
5〜10■/分の速度の時加工能率が高いということも
確認されており、おおむねこれらの領域で速度設定が必
要と考察される。According to experiments, when the interpolar condition worsens, at least 2
It has been found that if the speed is not higher than 0-min, a speed of about 200++/min is required when arc discharge occurs and a large amount of machining powder stays between the poles. In addition, for stable machining, in finishing machining with a surface roughness of 1.5μRmax or less,
It has also been confirmed that the machining efficiency is high at a speed of 5 to 10 .mu./min, and it is considered that the speed should generally be set in these ranges.
以上のように、本発明によれば放電の異常を既述検出方
法で判別し、該検出結果をもとにして極必3)
同状態の回復をはかるためにサーボゲインを変化させて
サーボアクチェータの速度を制御し極間間隙における間
隙の開離と接近をすみやかに行うという従来にない放電
加工装置の提供を行うものである。As described above, according to the present invention, an abnormality in discharge is determined by the above-described detection method, and based on the detection result, the servo gain is changed to recover the servo actuator. The purpose of the present invention is to provide an unprecedented electric discharge machining apparatus that controls the speed of the gap between the poles and quickly opens and closes the gap between the poles.
第1図は従来の放電加工装置を示す原理図、第2図は本
発明になる原理の説明図、第3図は周波数スペクトル分
析回路説明図、第4図は、異常状態検出判別回路図、第
5図はその表示回路図、第6図は本発明の詳細な説明図
である。図中10は電極、14は被加工物、18は加工
電源、67は異常検知カウンターである。
なお、図中同一符号は同−又は相当部分を示す。
代理人 大暑 増雄
(14)Fig. 1 is a principle diagram showing a conventional electrical discharge machining device, Fig. 2 is an explanatory diagram of the principle according to the present invention, Fig. 3 is an explanatory diagram of a frequency spectrum analysis circuit, and Fig. 4 is an abnormal state detection/discrimination circuit diagram. FIG. 5 is a display circuit diagram thereof, and FIG. 6 is a detailed explanatory diagram of the present invention. In the figure, 10 is an electrode, 14 is a workpiece, 18 is a processing power source, and 67 is an abnormality detection counter. Note that the same reference numerals in the figures indicate the same or equivalent parts. Agent Masuo Ohatsu (14)
Claims (1)
、その極間間隙内に放電を発生させて上記被加工物を加
工する放電加工装置であって、極間間隙長を制御するサ
ーボ機構を備えたものにおいて、電極と被加工物の極間
間隙で放電した際の極間間隙における電気信号中の周波
数成分の分布を検知する検知手段と、この検知手段によ
り検知される周波数成分の分布を予め設定した周波数成
分の分布を比較する比較手段と、上記比較手段の出力信
号に基ずいて極間間隙状態を判断して信号を出力する極
間間隙状態判別手段と、この判別手段の出力に基づいて
上記サーボ機構のサーボゲインを制御する制御手段を具
備することを特徴とする放電加工装置。An electric discharge machining device that processes the workpiece by making an electrode and a workpiece face each other with an insulating machining liquid interposed therebetween, and generating an electric discharge within the gap between the electrodes, and controlling the gap length between the electrodes. In an apparatus equipped with a servo mechanism, a detection means for detecting the distribution of frequency components in an electric signal in the gap between the electrodes and the workpiece when electric discharge occurs in the gap between the electrodes and the workpiece, and a frequency component detected by the detection means. a comparison means for comparing distributions of frequency components whose distributions are set in advance; an interpole gap state determining means for determining a state of the interpolar gap based on an output signal of the comparing means and outputting a signal; and this determining means An electric discharge machining apparatus comprising: a control means for controlling a servo gain of the servo mechanism based on the output of the servo mechanism.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP14072383A JPS6034221A (en) | 1983-08-01 | 1983-08-01 | Electric discharge machine |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP14072383A JPS6034221A (en) | 1983-08-01 | 1983-08-01 | Electric discharge machine |
Publications (1)
Publication Number | Publication Date |
---|---|
JPS6034221A true JPS6034221A (en) | 1985-02-21 |
Family
ID=15275207
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP14072383A Pending JPS6034221A (en) | 1983-08-01 | 1983-08-01 | Electric discharge machine |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS6034221A (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6723941B2 (en) | 2001-11-29 | 2004-04-20 | Mitsubishi Denki Kabushiki Kaisha | Wire electric-discharge machining apparatus |
WO2011161764A1 (en) * | 2010-06-22 | 2011-12-29 | 三菱電機株式会社 | Electro-discharge machining control device |
-
1983
- 1983-08-01 JP JP14072383A patent/JPS6034221A/en active Pending
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6723941B2 (en) | 2001-11-29 | 2004-04-20 | Mitsubishi Denki Kabushiki Kaisha | Wire electric-discharge machining apparatus |
WO2011161764A1 (en) * | 2010-06-22 | 2011-12-29 | 三菱電機株式会社 | Electro-discharge machining control device |
JP5372252B2 (en) * | 2010-06-22 | 2013-12-18 | 三菱電機株式会社 | Electric discharge machining control device |
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