JPH0547326B2 - - Google Patents

Info

Publication number
JPH0547326B2
JPH0547326B2 JP58067640A JP6764083A JPH0547326B2 JP H0547326 B2 JPH0547326 B2 JP H0547326B2 JP 58067640 A JP58067640 A JP 58067640A JP 6764083 A JP6764083 A JP 6764083A JP H0547326 B2 JPH0547326 B2 JP H0547326B2
Authority
JP
Japan
Prior art keywords
circuit
charging
capacitor
current
discharge
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 - Lifetime
Application number
JP58067640A
Other languages
Japanese (ja)
Other versions
JPS59192422A (en
Inventor
Kyoshi Inoe
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Inoue Japax Research Inc
Original Assignee
Inoue Japax Research Inc
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Inoue Japax Research Inc filed Critical Inoue Japax Research Inc
Priority to JP6764083A priority Critical patent/JPS59192422A/en
Publication of JPS59192422A publication Critical patent/JPS59192422A/en
Publication of JPH0547326B2 publication Critical patent/JPH0547326B2/ja
Granted legal-status Critical Current

Links

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B23MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23HWORKING OF METAL BY THE ACTION OF A HIGH CONCENTRATION OF ELECTRIC CURRENT ON A WORKPIECE USING AN ELECTRODE WHICH TAKES THE PLACE OF A TOOL; SUCH WORKING COMBINED WITH OTHER FORMS OF WORKING OF METAL
    • B23H7/00Processes or apparatus applicable to both electrical discharge machining and electrochemical machining
    • B23H7/02Wire-cutting
    • B23H7/04Apparatus for supplying current to working gap; Electric circuits specially adapted therefor

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Electrical Discharge Machining, Electrochemical Machining, And Combined Machining (AREA)

Description

【発明の詳細な説明】 本発明は放電加工装置、ワイヤカツト放電加工
装置の改良に関する。
DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in electrical discharge machining equipment and wire cut electrical discharge machining equipment.

従来、放電加工において超硬材の加工を行なう
とか、電極有消耗で加工速度を上げたい場合と
か、ワイヤカツトする場合等においては、加工用
電源としてトランジスタスイツチング回路にコン
デンサ放電を組合せることによつて、コンデンサ
の充電速度を高め放電繰返し周波数を高めると共
に、スイツチングパルスでは得られない程に放電
電流波高値を高めることができ加工速度を向上さ
せることができる。
Conventionally, when machining carbide materials in electrical discharge machining, when increasing the machining speed with consumable electrodes, when cutting wire, etc., it has been possible to combine capacitor discharge with a transistor switching circuit as a power source for machining. As a result, the charging speed of the capacitor can be increased, the discharge repetition frequency can be increased, and the peak value of the discharge current can be increased to an extent that cannot be obtained by switching pulses, thereby improving the machining speed.

しかしながらコンデンサの充電を高速にするた
めに充電抵抗を微小に設定するから加工間隙でア
ーク放電が発生するときは、スイツチングパルス
電源から直接間隙に電流が流れ込み、ワイヤカツ
トでは断線の原因になり、加工精度が低下する。
However, in order to charge the capacitor at a high speed, the charging resistance is set to a very small value, so when arc discharge occurs in the machining gap, current flows directly from the switching pulse power source into the gap, which can cause wire cuts and damage to the machining process. Accuracy decreases.

本発明はこのようなアーク、短絡時にパルス電
源、サーボ送り等を迅速に制御するために加工間
隙の異常を迅速、正確に検出するために発明され
たもので、パルス電源とコンデンサとを接続する
回路の電流に基づいた波形信号を検出する回路
と、前記コンデンサと加工間隙を接続する回路の
電流基づいた波形信号を検出する回路とを設け、
前記コンデンサの充電回路に設けられた電流波形
信号を検出する回路と、放電回路に設けられた電
流波形信号を検出する回路とを設けると共に、前
記両検出回路の検出電流波形信号を比較し、該両
検出電流波形信号の所定レベル以上の近似に応じ
前記加工間隙状態の悪化を検出して制御信号を出
力する比較回路を設けて成ることを特徴とする。
The present invention was invented in order to quickly and accurately detect abnormalities in the machining gap in order to quickly control the pulse power supply, servo feed, etc. in the event of such an arc or short circuit. A circuit for detecting a waveform signal based on a current in the circuit, and a circuit for detecting a waveform signal based on a current in a circuit connecting the capacitor and the processing gap,
A circuit for detecting a current waveform signal provided in the charging circuit of the capacitor and a circuit for detecting a current waveform signal provided in the discharging circuit are provided, and the detected current waveform signals of both the detection circuits are compared and the current waveform signal detected by the two detection circuits is compared. The present invention is characterized in that a comparison circuit is provided which detects deterioration of the machining gap condition and outputs a control signal in accordance with approximation of both detected current waveform signals to a predetermined level or higher.

以下図面の一実施例によつて本発明を説明す
る。1はワイヤ電極で、リール2から供給されリ
ール3に巻取り移動する。途中ガイド4間を移動
し、この部分に被加工体5を対向して放電加工す
る。6は被加工体を固定支持するテーブルで、通
常このテーブルにNC制御による加工形状送りを
与えて加工する。7が加工エネルギ供給の電源、
8がオン・オフのトランジスタスイツチ、9がス
イツチングのゲートパルスを発生するパルサであ
る。電源7とスイツチ8の直列回路はワイヤ電極
1と被加工体5の加工間隙に並列接続されてい
る。10は加工間隙に並列接続されたコンデン
サ、11はスイツチ8によるスイツチングパルス
電源とコンデンサ10との間に流れる電流に基づ
いた波形信号を検出する検出回路、12はコンデ
ンサ10と加工間隙との間に流れる電流に基づい
た波形信号を検出する検出回路である。13は両
検出回路11,12の検出波形信号を比較して加
工間隙の放電状態を判別する比較回路、14は前
記比較回路13の判別比較出力に基づいて出力す
る比較出力によつて放電状態がアーク、短絡等の
異常が判別されたときパルサ9を制御し、ゲート
パルスの主として休止幅τoffを増大することによ
り正常復帰を行なわせる制御装置である。
The present invention will be explained below with reference to an embodiment of the drawings. A wire electrode 1 is supplied from a reel 2 and wound onto a reel 3. It moves between the guides 4 on the way, and electrical discharge machining is performed on the workpiece 5 facing this part. Reference numeral 6 denotes a table that fixedly supports the workpiece, and processing is normally performed by giving processing shape feed to this table using NC control. 7 is a power supply for processing energy supply,
8 is an on/off transistor switch, and 9 is a pulser that generates a gate pulse for switching. A series circuit of a power source 7 and a switch 8 is connected in parallel to the machining gap between the wire electrode 1 and the workpiece 5. 10 is a capacitor connected in parallel to the machining gap, 11 is a detection circuit that detects a waveform signal based on the current flowing between the switching pulse power supply by switch 8 and the capacitor 10, and 12 is between the capacitor 10 and the machining gap. This is a detection circuit that detects a waveform signal based on the current flowing through the circuit. 13 is a comparison circuit that compares the detection waveform signals of both detection circuits 11 and 12 to determine the discharge state of the machining gap; 14 is a comparison output output based on the discrimination comparison output of the comparison circuit 13, which determines the discharge state. This is a control device that controls the pulser 9 when an abnormality such as an arc or a short circuit is detected, and restores normality by increasing the pause width τoff of the gate pulse.

ワイヤカツトはワイヤ電極1を矢印方向に走行
移動させながら被加工体5と対向した間隙にパル
ス放電を行なつて加工するが、パルス電圧はパル
ス8によつてトランジスタスイツチ8がオン・オ
フスイツチングすることにより供給され、これに
よりコンデンサ10が充放電を行ない放電電流波
高値を増大したパルス電流の放電が行なわれる。
このとき電源電圧を増大し充電電流を増大してコ
ンデンサ10に急速充電を行なうことができ、放
電繰返数を高めて高速放電加工を行なうことがで
きる。このコンデンサ10の急速充放電を繰返し
ても電源スイツチ8がオンパルスτon、オフパル
スτoffのオン・オフスイツチングを繰返すことに
よつて安定した放電加工を行なえる効果がある。
A wire cut is processed by applying pulse discharge to the gap facing the workpiece 5 while moving the wire electrode 1 in the direction of the arrow, and the pulse voltage is turned on and off by the transistor switch 8 according to the pulse 8. As a result, the capacitor 10 is charged and discharged, and a pulse current with an increased peak value of the discharge current is discharged.
At this time, the power supply voltage is increased and the charging current is increased to rapidly charge the capacitor 10, and the number of discharge repetitions can be increased to perform high-speed electrical discharge machining. Even if this rapid charging and discharging of the capacitor 10 is repeated, stable electric discharge machining can be performed by the power switch 8 repeating on/off switching of the on-pulse τon and the off-pulse τoff.

しかしてスイツチングパルス電流は検出回路1
1によつて、またコンデンサ10と加工間隙を結
ぶ回路の放電電流は検出回路12によつて各々検
出され、両回路の検出波形信号が比較回路13に
よつて比較されるが、通常ワイヤ電極1と被加工
体5の加工間隙に正常パルス放電が行なわれてい
れば、検出回路11,12の波形信号には位相差
があり、且つ電流波高値、波形等に相違がある。
即ち、放電加工に於けるコンデンサ充放電加工回
路は、放電電力を充放電電源から充電回路を介し
てコンデンサに(充電)時間を掛けて蓄積(充
電)し、この充電電荷(電圧)を電極と被加工体
間の放電間隙に印加し、該放電間隙に於ける放電
の開始後のより短い(放電)時間の内に大きい放
電電流振幅値を有する放電として放出するもので
ある。そして、その充電回路は一般的に(特に特
別な電極低消耗加工条件等でない以上)放電回路
に対し、種々の回路素子使用の構成を採り得るも
のの、正常な充電及び放電時、即ち正常放電加工
時に於ては、充電時間(時定数:Tc)が放電時
間(時定数;TD)に対して著しく長く(Tc》
TD)、そして他方放電電流振幅値(IDP)が充電
電流最大値(ICP)に対して著しく大きい
(IDP》ICP)状態で、充放電を繰り返して放電
加工が行なわれるものである。そしてかかるコン
デンサ充放電に関する事項は、例えば昭和36年4
月15日に(株)コロナ社から発行された鳳誠三郎及び
藤倉尚雄共著の「改訂 放電加工」の特にコンデ
ンサ放電に関する記載(第25〜47頁)等によるま
でもなく周知のことである。
Therefore, the switching pulse current is detected by the detection circuit 1.
1 and the discharge current of the circuit connecting the capacitor 10 and the machining gap are respectively detected by the detection circuit 12, and the detected waveform signals of both circuits are compared by the comparison circuit 13. If normal pulse discharge is performed in the machining gap between the workpiece 5 and the workpiece 5, there is a phase difference between the waveform signals of the detection circuits 11 and 12, and there is also a difference in current peak value, waveform, etc.
In other words, the capacitor charging/discharging machining circuit used in electrical discharge machining accumulates (charges) discharged power from a charging/discharging power source via a charging circuit in a capacitor over time, and then uses this charged charge (voltage) between electrodes and It is applied to the discharge gap between the workpieces and is emitted as a discharge having a large discharge current amplitude value within a shorter (discharge) time after the start of discharge in the discharge gap. In general, the charging circuit can be configured using various circuit elements compared to the discharge circuit (as long as there are no special low electrode consumption machining conditions), but during normal charging and discharging, that is, normal discharge machining. In some cases, the charging time (time constant: Tc) is significantly longer than the discharging time (time constant: TD) (Tc》
TD) and, on the other hand, the discharge current amplitude value (IDP) is significantly larger than the maximum charging current value (ICP) (IDP》ICP), and electrical discharge machining is performed by repeating charging and discharging. Matters related to capacitor charging and discharging are, for example, published in April 1963.
This is well known, as is evident from ``Revised Electrical Discharge Machining'', co-authored by Seizaburo Otori and Nao Fujikura, published by Coronasha Co., Ltd. on May 15, 2017, especially the description regarding capacitor discharge (pages 25 to 47).

しかして、本発明によれば、検出回路11,1
2によりコンデンサ10の充電回路と放電回路の
各電流を波形信号として検出しているから、充電
及び放電時間の時間幅、又は充電及び放電電流の
波高値の一方又は両方を検出して、比較回路13
で、夫々の大小関係の比較判別することができ、
従つて前記比較に際して何等かの判別基準等を設
定することにより、前記コンデンサの充放電の状
態、即ち充放電の特性を知ることができ、引いて
は、放電間隙に於ける放電状態乃至放電加工状態
を知ることができることになる。
Therefore, according to the present invention, the detection circuits 11,1
Since each current of the charging circuit and discharging circuit of the capacitor 10 is detected as a waveform signal by 2, one or both of the time width of the charging and discharging time or the peak value of the charging and discharging current is detected and the comparison circuit 13
You can compare and determine the size relationship of each,
Therefore, by setting some discrimination criteria for the comparison, it is possible to know the charging/discharging state of the capacitor, that is, the charging/discharging characteristics, and by extension, the discharge state in the discharge gap or the discharge machining. This will allow you to know the status.

しかして、本発明於ては、コンデンサ10の充
電回路と放電回路に夫々電流波形検出回路11,
12を設け、上記コンデンサ10の1充電毎の充
電と放電の検出波形信号を比較回路13に於て比
較することにより放電加工状態の判別更には制御
信号を出力させようとするもので、前記比較回路
13に於ける電流波形信号の比較、解析は、コン
デンサの充放電電流波形の前述した基本的な特性
の関係から、例えば次の如くに行なわれる。
Therefore, in the present invention, the current waveform detection circuit 11 is provided in the charging circuit and the discharging circuit of the capacitor 10, respectively.
12 is provided, and the comparator circuit 13 compares the detection waveform signals of charging and discharging each time the capacitor 10 is charged, thereby determining the electrical discharge machining state and outputting a control signal. Comparison and analysis of the current waveform signals in the circuit 13 are performed, for example, as follows from the relationship of the above-mentioned basic characteristics of the charging and discharging current waveforms of the capacitor.

充放電電流の特性として充電時間の長さと放電
時間の長さ(放電パルスの幅)を検出比較する場
合には、種々なやり方があるものの、例えば充電
及び放電電流が、夫々或る値を越えている期間ゲ
ートを開いてクロツクパルスを積算カウントし、
各カウント数を必要に応じ予め設定した適宜の比
率(例えば放電側のカウント数をn倍等)で調整
して比較するか演算して、大小関係、更には大小
の程度等を信号として出力させるように、又充放
電電流の特性として充電電流の振幅等の大きさと
放電電流の振幅等大きさを検出比較する場合に
は、例えば放電電流が或る値を越えている期間該
放電電流信号をA/D変換してカウントしたカウ
トデイジタル信号と、正常加工時に予定される前
記放電電流のA/D変換期間とほぼ同一の期間充
電電流をその充電開始後或る値を越えた時点から
A/D変換してカウントしたカウントデイジタル
信号とを必要に応じ予め設定した適宜の比率で調
整して比較するか演算して、大小関係更には大小
の程度等を信号として出力させ、放電加工状態や
当該放電パルスの状態等を判別するものである。
There are various ways to detect and compare the length of charging time and the length of discharging time (width of discharge pulse) as characteristics of charge/discharge current, but for example, when the charging and discharging currents exceed a certain value, The gate is opened for the period of time, and the clock pulses are cumulatively counted.
Each count is adjusted according to a preset appropriate ratio (for example, the count number on the discharge side is multiplied by n) and compared or calculated, and the magnitude relationship, and furthermore, the degree of magnitude, etc. is output as a signal. Similarly, when detecting and comparing the amplitude of the charging current and the amplitude of the discharging current as characteristics of the charging/discharging current, for example, the discharging current signal is detected during the period when the discharging current exceeds a certain value. The count digital signal counted by A/D conversion and the charging current are applied for a period almost the same as the A/D conversion period of the discharge current scheduled during normal machining. The D-converted and counted count digital signal is adjusted as necessary at an appropriate ratio set in advance, compared or calculated, and the magnitude relationship and degree of magnitude are output as signals to determine the electrical discharge machining status and the relevant This is used to determine the state of discharge pulses, etc.

そして、コンデンサの当該充放電の良否は、前
述の如く一般的には充放電時間の長さの間、及び
充放電電流の振幅(大きさ)間に差がある程良好
で、間隙状態はその発生頻度又は割合で判別でき
るものであり、加工間隙が所望予定値よりも狭い
とか、加工屑等による汚濁状態が進行すれば、前
述充放電電流間の差異の程度が減少し、加工間隙
が短絡又は加工屑等による疑以短絡状態等になる
と充電電流はそのまま放電電流(短絡電流)とな
るから上記充放電電流間の差異はなくなるもので
ある。
As mentioned above, generally speaking, the quality of charging and discharging of a capacitor is better as there is a difference between the length of charging and discharging time and the amplitude (magnitude) of charging and discharging current. This can be determined by the frequency or rate of occurrence, and if the machining gap is narrower than the desired expected value or if the contamination with machining debris progresses, the degree of difference between the charging and discharging currents will decrease, and the machining gap will be short-circuited. Or, if a short circuit occurs due to machining debris or the like, the charging current becomes the discharging current (short circuit current), so the difference between the charging and discharging currents disappears.

従つて、比較回路13の判別による検出出力信
号は制御装置14に正常、異常の信号を加え、異
常放電のときはパルサ9のオフパルス幅τoffを増
大して正常復帰を行なわせ、正常のときは、τoff
を短絡制御して放電繰返しを高めるよう制御する
ことによつて加工速度を増大させる。以上、検出
波形信号の位相差によりり正常,異常放電を検出
する実施例の説明を行なつたが、電流波高値の波
形や電流波形そのものを比較判別することによつ
て同様の作用効果が得られる。
Therefore, the detection output signal determined by the comparator circuit 13 applies a normal/abnormal signal to the control device 14, and when an abnormal discharge occurs, the off-pulse width τoff of the pulser 9 is increased to restore normality; , τoff
Machining speed is increased by short-circuiting and controlling to increase discharge repetition. Above, we have described an embodiment in which normal and abnormal discharges are detected based on the phase difference of the detection waveform signals, but similar effects can be obtained by comparing and determining the waveform of the current peak value or the current waveform itself. It will be done.

また比較回路13の検出信号によつて加工間隙
のサーボ駆動装置を制御したり、図示しないノズ
ルからの加工液の噴流を制御したり、ワイヤ電極
1の走行速度とか、ワイヤ強制振動を与える場合
にその振動制御を行なうことができる。またそれ
らの手動制御のために表示装置に比較回路13の
出力を供給して表示することができる。
The detection signal from the comparison circuit 13 can also be used to control the servo drive device for the machining gap, control the jet of machining fluid from a nozzle (not shown), control the running speed of the wire electrode 1, and when applying forced vibration to the wire. The vibration control can be performed. Further, for manual control thereof, the output of the comparator circuit 13 can be supplied to and displayed on a display device.

以上のように本発明はパルス電源とコンデンサ
とを接続する回路の電流を検出する回路と、前記
コンデンサと加工間隙を接続する回路の電流を検
出する回路とを設け、両検出回路の信号を比較し
て、その位相差、波高値、波形等の比較判別によ
り加工間隙の放電状態を判別検出するようにした
から極めて正確な放電状態の検出ができ、検出に
よつてパルサ等の制御が適確に行なえ、コンデン
サ放電を利用した放電加工が高速度に高能率に行
なえる効果がある。
As described above, the present invention includes a circuit that detects the current of the circuit that connects the pulse power source and the capacitor, and a circuit that detects the current of the circuit that connects the capacitor and the machining gap, and compares the signals of both detection circuits. Then, the discharge state in the machining gap is determined and detected by comparing and determining the phase difference, peak value, waveform, etc. Therefore, it is possible to detect the discharge state extremely accurately, and the control of the pulsar etc. can be performed appropriately by detection. This has the effect that electrical discharge machining using capacitor discharge can be performed at high speed and with high efficiency.

なお電流検出回路は抵抗両端の電圧降下を計測
したり、パルス電流の発生する磁界を検出する等
任意の方式回路を利用することができる。
Note that the current detection circuit may be any type of circuit that measures the voltage drop across a resistor or detects a magnetic field generated by a pulse current.

【図面の簡単な説明】[Brief explanation of the drawing]

図面は本発明の一実施例回路構成図である。 1…ワイヤ電極、5…被加工体、7…電源、8
…スイツチ、9…パルサ、10…コンデンサ、1
1,12…電流検出回路、13…比較回路。
The drawing is a circuit configuration diagram of an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Wire electrode, 5... Workpiece, 7... Power supply, 8
...Switch, 9...Pulser, 10...Capacitor, 1
1, 12... Current detection circuit, 13... Comparison circuit.

Claims (1)

【特許請求の範囲】 1 電極と被加工体とが相対向して形成する加工
間隙に並列に充放電コンデンサを接続し、該コン
デンサを直流電源から設定されたオン・オフ時間
幅に開閉が制御されるスイツチ素子を介して充電
するようにした放電加工装置に於て、 前記コンデンサの充電回路に設けられた電流波
形信号を検出する回路と、放電回路に設けられた
電流波形信号を検出する回路と、前記両検出回路
の検出電流波形信号を比較し、該両検出電流波形
信号の所定レベル以上の近似に応じ、前記加工間
隙状態の悪化を検出して制御信号を出力する比較
回路を設けて成ることを特徴とする放電加工装
置。
[Claims] 1. A charging/discharging capacitor is connected in parallel to a machining gap formed by facing each other between an electrode and a workpiece, and the opening/closing of the capacitor is controlled by a DC power supply at a set on/off time width. In an electric discharge machining apparatus that charges via a switch element, the capacitor has a charging circuit for detecting a current waveform signal, and a discharging circuit for detecting a current waveform signal. and a comparison circuit that compares the detected current waveform signals of both the detection circuits, detects deterioration of the machining gap condition and outputs a control signal according to the approximation of both the detected current waveform signals to a predetermined level or higher. An electrical discharge machining device characterized by:
JP6764083A 1983-04-15 1983-04-15 Electric discharge machine Granted JPS59192422A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP6764083A JPS59192422A (en) 1983-04-15 1983-04-15 Electric discharge machine

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP6764083A JPS59192422A (en) 1983-04-15 1983-04-15 Electric discharge machine

Publications (2)

Publication Number Publication Date
JPS59192422A JPS59192422A (en) 1984-10-31
JPH0547326B2 true JPH0547326B2 (en) 1993-07-16

Family

ID=13350795

Family Applications (1)

Application Number Title Priority Date Filing Date
JP6764083A Granted JPS59192422A (en) 1983-04-15 1983-04-15 Electric discharge machine

Country Status (1)

Country Link
JP (1) JPS59192422A (en)

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS55164428A (en) * 1979-06-06 1980-12-22 Inoue Japax Res Inc System for electric discharge machining

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS55164428A (en) * 1979-06-06 1980-12-22 Inoue Japax Res Inc System for electric discharge machining

Also Published As

Publication number Publication date
JPS59192422A (en) 1984-10-31

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