JP2001018121A - Electric discharge machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily and surely check interference of a lifting type machining tank with an electrode so as to prevent its damage by the machining tank colliding with an automatic electrode replacing device, by detecting the interference of the electrode with the lifted machining tank in an upper part of a machining tank wall surface. SOLUTION: A block 23 is provided in upper one corner of a wall surface 22 of a machining tank, and one end of a wire 24 is fixed to this block. The wire 24, holding a distance in parallel to an upper side of the machining tank wall surface 22, is extended to the other corner of the wall surface 22 by applying tension with a spring 25 through a metal-made plate 26 in the other end. A proximity sensor 27 is mounted in the vicinity of the plate 26. The wire 24 comes into contact with an electrode 28 before the electrode 28 set to a magazine 21 of an automatic electrode replacing device interferes with the machining tank, and extension of the spring 25 is detected by the sensor 27. In this way, the. machining tank of lifting type can be safely stopped before damaging the electrode 28.

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】この発明は、昇降式加工槽と
自動電極交換装置を備えた放電加工機に係り、さらに詳
細には昇降式加工槽と自動電極交換装置に設置された電
極の干渉防止手段に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric discharge machine equipped with an elevating type machining tank and an automatic electrode exchanging device, and more particularly, to the prevention of interference between electrodes installed in an elevating type machining tank and an automatic electrode exchanging device. About the means.

【０００２】[0002]

【従来の技術】従来、昇降式加工槽と自動電極交換装置
を備えた放電加工機では、自動電極交換装置に電極を取
り付ける際は、昇降式加工槽を下方に降ろしておいて取
り付け作業を行うことが多く、取り付け作業が終了すれ
ば昇降式加工槽を加工位置まで上昇させながら自動電極
交換装置に取り付けた電極と昇降式加工槽が干渉しない
かどうかを目視によってチェックする必要があった。2. Description of the Related Art Conventionally, in an electric discharge machine equipped with an elevating type machining tank and an automatic electrode changing device, when mounting an electrode on the automatic electrode exchanging device, the elevating type machining tank is lowered and mounting work is performed. In many cases, when the mounting operation is completed, it is necessary to visually check whether or not the electrode attached to the automatic electrode changing device and the elevating type processing tank interfere with each other while raising the elevating type processing tank to the processing position.

【０００３】[0003]

【発明が解決しようとする課題】ところが、自動電極交
換装置に取り付けた電極に、下方から上昇する昇降式加
工槽が干渉しないかどうかを目視でチェックすること
は、複数個の電極の形状が複雑で大きさも不揃いである
ために困難であった。また、実際に干渉チェックを行お
うとして自動電極交換装置に電極を取り付けた後で、昇
降式加工槽を上昇させた際に、作業者の不注意によって
停止できなかった昇降式加工槽が、自動電極交換装置に
取り付けた電極に衝突し、電極が破損してしまうことが
あった。そこで、この発明の目的は、昇降式加工槽と自
動電極交換装置に取り付けた電極の干渉チェックを容易
に確実に行うこと、また、干渉チェック中に作業者の不
注意によって昇降式加工槽と自動電極交換装置が衝突
し、電極が破損するのを防止することにある。However, it is difficult to visually check whether or not an ascending and descending processing tank ascending from below interferes with an electrode attached to an automatic electrode changing device because the shape of a plurality of electrodes is complicated. It was difficult because of the irregular size. In addition, after the electrode was attached to the automatic electrode changer to actually perform the interference check, when the lifting / lowering processing tank was raised, the lifting / lowering processing tank that could not be stopped There was a case where the electrode hit the electrode attached to the electrode exchange device and was damaged. Therefore, it is an object of the present invention to easily and reliably perform an interference check between an elevating type processing tank and an electrode attached to an automatic electrode changing device, and to automatically and automatically check an elevating type processing tank during an interference check by an operator. An object of the present invention is to prevent an electrode exchange device from colliding and damaging an electrode.

【０００４】[0004]

【課題を解決するための手段】前述のような課題を解決
するために、本願発明は、テーブルに固定された加工物
に放電をする電極と、加工物に対し昇降可能で、溜めた
放電加工液に加工物を浸漬可能な加工槽と、電極を別の
電極に交換する自動電極交換装置と、自動電極交換装置
により交換される電極及び別の電極を収納するマガジン
とを備える放電加工機において、加工槽壁面の上部に、
電極と昇降する加工槽との干渉を検出する検出手段を備
える放電加工機である。このような構成により、自動電
極交換装置のマガジンに電極をセットさせた後、目視に
より衝突を予測ができずに昇降式加工槽を上昇させた場
合に、加工槽と交換された電極とが干渉するようなとき
でも、加工槽と電極が干渉する前に昇降式加工槽の上部
に設置された検出手段と電極が接触し、検出手段が制御
装置に信号を送るので、加工槽と電極が接触して電極が
破損する前に昇降式加工槽を安全に停止することができ
る。SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides an electrode for discharging a workpiece fixed to a table, an electric discharge machine capable of moving up and down with respect to the workpiece, and a stored discharge machining. In an electric discharge machine equipped with a machining tank capable of immersing a workpiece in a liquid, an automatic electrode exchange device for exchanging an electrode for another electrode, and a magazine for accommodating an electrode exchanged by the automatic electrode exchange device and another electrode. , On the top of the processing tank wall,
This is an electric discharge machine equipped with a detecting means for detecting interference between an electrode and an ascending and descending machining tank. With such a configuration, if the electrode is set in the magazine of the automatic electrode changer and then the lifting / lowering type processing tank is raised without being able to visually predict the collision, the processing tank and the replaced electrode may interfere. Even in such a case, before the processing tank and the electrode interfere with each other, the detection means installed on the upper and lower type processing tank comes into contact with the electrode, and the detection means sends a signal to the control device. Thus, the lifting / lowering type processing tank can be safely stopped before the electrode is damaged.

【０００５】この電極と加工槽との干渉を検出する検出
手段としては、加工槽の上部にワイヤーを張設し、その
ワイヤーの端部に近接センサーを取り付けることによ
り、目視で予測できずに誤って電極がワイヤーに接触し
ワイヤーが引っ張られると近接センサーの出力が変化
し、電極を駆動させる制御装置に停止信号を送る手段が
ある。これにより、上昇した加工槽と電極が接触して電
極が破損する前に、昇降式加工槽を安全に停止すること
ができるとともに、簡単な構成で検出手段を低コストで
取り付けることができ、張設されているワイヤーを目視
点検の目安にして段取り替えを素早く行うこともでき
る。また、この近接センサーによる、ワイヤーの挙動を
検知する手段の他に、ワイヤーの一端を電気的な接点と
して、ワイヤーが引っ張られることによって接点が外れ
ると、電気的な信号を発生する検出手段や、近接センサ
ーの代わりにマイクロスイッチを使用する検出手段があ
る。更に、加工槽の上面と自動電極交換装置にセットし
た電極とが接近し、干渉する可能性があることを検出す
る、ワイヤーを利用しない他の手段としては、加工槽上
面に発光部と受光センサーとを設置し、この間を何物か
が横切ったことを検出する手段もある。発光部に可視光
線を発射させることで、目視点検の目安になり段取り替
えを簡単に行うことができる上、ワイヤー張設後に弛み
が無くなり、加工槽上面の長い距離を検出対象とでき
る。[0005] As a detecting means for detecting the interference between the electrode and the processing tank, a wire is stretched over the processing tank and a proximity sensor is attached to the end of the wire, thereby making it impossible to visually predict the error. When the electrode contacts the wire and the wire is pulled, the output of the proximity sensor changes, and there is a means for sending a stop signal to a control device for driving the electrode. Thus, before the electrode is broken due to the contact between the raised processing tank and the electrode, the lifting and lowering processing tank can be safely stopped, and the detecting means can be attached with a simple configuration at low cost. Using the installed wires as a guide for visual inspection, the setup can be changed quickly. Further, in addition to the means for detecting the behavior of the wire by this proximity sensor, one end of the wire as an electrical contact, detection means for generating an electrical signal when the contact is released by pulling the wire, There is a detection means using a microswitch instead of a proximity sensor. Further, other means that do not use wires, such as detecting that the upper surface of the processing tank and the electrode set in the automatic electrode changer approach and may interfere with each other, include a light emitting unit and a light receiving sensor on the upper surface of the processing tank. There is also a means of detecting that something has crossed between them. By emitting visible light to the light-emitting portion, visual inspection can be used as a guide and setup can be easily changed. In addition, slack can be eliminated after the wire is stretched, and a long distance on the upper surface of the processing tank can be detected.

【０００６】[0006]

【発明の実施の形態】以下、本願発明の一実施例を図面
に基づいて詳細に説明する。図２は昇降式加工槽を備え
た放電加工機の全体的構成を概念的に例示している。加
工物１を固定するワークテーブル２を前部に載せるベッ
ド３の中央部には、Ｘ軸ガイド４の上にサドル５がＸ軸
方向に移動可能に固定されている。そして、そのサドル
５の上に固定されるＹ軸ガイド６の上には、コラム７が
Ｙ軸方向に移動可能に固定され、さらにコラム７に固定
されるＺ軸ガイド８にはヘッド９がＺ軸方向に移動可能
に取付けられている。これにより、ヘッド９は、ベッド
３の加工物１に対しＸ・Ｙ・Ｚ軸の３次元方向に自在に
移動できる。加工物１を載せるテーブル２を壁面で囲む
ように設置された加工槽１１は、図示していない加工槽
駆動装置によってテーブル２に対して上下方向に駆動さ
れる。また、加工槽１１の内部には、ベッド３の後部に
設置された加工液タンク１５から、加工液供給ポンプ１
３がくみ上げた加工液が、フィルター１４・加工液冷却
装置１６・テーブル２下の配管を通って供給されてい
る。加工槽１１に供給された加工液は、加工槽１１の側
面に設けられたオーバーフロー穴１７からオーバーフロ
ーしてベッド前部に回収され、再び加工液タンク１５に
回収される。このような構成の放電加工機は、加工槽１
１を上昇させて、加工物１を加工液中に沈めて、加工物
１とヘッド９に固定された自動交換チャック２０に取付
けられた電極１０の間隙を規定の間隙になるように、電
極１０の位置を、Ｘ・Ｙ・Ｚ軸方向へそれぞれ配置され
たボールネジ１９，１９，１９を駆動するサーボモータ
一１８，１８，１８で制御し、ヘッド９に固定された電
極１０とテーブル２に固定された加工物１の間に、図示
していない放電電源から電圧を印加し、加工物１と電極
１０の間に放電を発生させて、この放電のエネルギーで
加工物１の表面を溶融除去加工するものである。このよ
うな放電加工機においては、加工槽１１を昇降させるこ
とで加工液面を昇降させることができ、加工中は加工槽
１１を上昇させて加工物を加工液中に沈めて放電加工を
行い、段取作業時には加工槽１１を下降させて加工物を
加工液から出して段取作業を行う。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 2 conceptually illustrates the overall configuration of an electric discharge machine provided with an elevating machining tank. A saddle 5 is fixed on an X-axis guide 4 so as to be movable in the X-axis direction, at the center of a bed 3 on which a work table 2 for fixing a workpiece 1 is placed at the front. A column 7 is fixed on the Y-axis guide 6 fixed on the saddle 5 so as to be movable in the Y-axis direction, and a head 9 is mounted on a Z-axis guide 8 fixed on the column 7. It is mounted so that it can move in the axial direction. Thereby, the head 9 can freely move in the three-dimensional directions of the X, Y, and Z axes with respect to the workpiece 1 of the bed 3. The processing tank 11 installed so as to surround the table 2 on which the workpiece 1 is placed by a wall surface is driven vertically with respect to the table 2 by a processing tank driving device (not shown). Further, inside the processing tank 11, a processing liquid supply pump 1 is provided from a processing liquid tank 15 installed at the rear of the bed 3.
The working fluid pumped by 3 is supplied through a filter 14, a working fluid cooling device 16, and a pipe below the table 2. The processing liquid supplied to the processing tank 11 overflows from an overflow hole 17 provided on the side surface of the processing tank 11, is collected at the front of the bed, and is collected again in the processing liquid tank 15. The electric discharge machine having such a configuration is provided with a machining tank 1
Then, the workpiece 1 is immersed in the working fluid, and the electrode 10 is fixed so that the gap between the workpiece 1 and the electrode 10 attached to the automatic exchange chuck 20 fixed to the head 9 becomes a specified gap. Is controlled by servomotors 18, 18, 18 that drive ball screws 19, 19, 19 arranged in the X, Y, and Z axis directions, respectively, and are fixed to the electrode 10 fixed to the head 9 and the table 2. A voltage is applied from a discharge power supply (not shown) between the processed workpiece 1 to generate a discharge between the workpiece 1 and the electrode 10, and the surface of the workpiece 1 is melted and removed by the energy of the discharge. Is what you do. In such an electric discharge machine, the machining liquid level can be raised and lowered by raising and lowering the processing tank 11, and during processing, the processing tank 11 is raised and the workpiece is immersed in the processing liquid to perform electric discharge machining. During the setup operation, the processing tank 11 is lowered to take out the workpiece from the working fluid to perform the setup operation.

【０００７】図３は昇降式加工槽１１と自動電極交換装
置を備えた放電加工機の平面図を示している。上記のよ
うに加工槽１１を上昇させて、電極１０と加工物１の間
で放電を発生させて加工を行い、一工程目の加工が完了
したら加工槽１１を下降させて、自動電極交換装置のマ
ガジン２１を一工程目で使用した電極１０を返却する位
置に割出し位置決めし、ヘッド９が電極交換位置まで移
動して電極１０を自動電極交換装置のマガジン２１に返
却する。次にヘッドが待避位置に移動し、マガジン２１
が二工程目で使用する電極１０を交換位置に割出し位置
決めし、ヘッド９が電極交換位置に移動して二工程目で
使用する電極１０をクランプして、加工位置に移動す
る。その後、加工槽１１が上昇し、加工物１を加工液中
に沈めてから放電加工を行う。FIG. 3 is a plan view of an electric discharge machine equipped with a vertically movable machining tank 11 and an automatic electrode changing device. As described above, the processing tank 11 is raised, an electric discharge is generated between the electrode 10 and the workpiece 1, and the processing is performed. The index 21 is indexed and positioned at the position where the electrode 10 used in the first step is returned, and the head 9 moves to the electrode replacement position to return the electrode 10 to the magazine 21 of the automatic electrode replacement device. Next, the head moves to the retracted position, and the magazine 21
Locates and positions the electrode 10 used in the second step at the replacement position, the head 9 moves to the electrode replacement position, clamps the electrode 10 used in the second step, and moves to the processing position. Thereafter, the machining tank 11 is raised, and the workpiece 1 is immersed in the machining fluid, and then electric discharge machining is performed.

【０００８】図１は、図３の放電加工機におけるＡ−Ａ
線断面図を示している。加工槽１１の壁面２２の上部一
隅にブロック２３を設け、これにワイヤー２４の一端を
固定している。ブロック２３に一端を固定されたワイヤ
ー２４は、加工槽１１の壁面２２の上辺と平行に距離を
保って他端に金属製のプレート２６を介して、ばね２５
によって張力を掛けて加工槽１１の壁面２２の他方の隅
まで張られている。金属製のプレート２６の付近には近
接センサー２７が取付けられている。ワイヤー２４を取
りつけている位置は、加工槽１１の上部で自動電極交換
装置のマガジンにセットされた電極２８が、加工槽１１
と干渉する可能性のある軌道上の位置であり、近接セン
サー２７の位置はワイヤー２４が引張られて、ばね２５
の張力に抗してプレート２６が図１の矢印の方向に移動
した場合、移動したことを検出できる位置に設置してあ
る。また、ばね２５のばね定数はワイヤー２４が自動電
極交換装置のマガジン２１にセットされた電極２８と接
触して、ワイヤー２４が引張られたときに電極２８が破
損する前にばね２５が伸びて、プレート２６が近接セン
サー２７の検出範囲から外れるだけの変位をするのに十
分弱く設定されている。以上のように構成された放電加
工機では、自動電極交換装置のマガジン２１にセットさ
れた電極２８と昇降式加工槽１１の上部の壁面２２が干
渉する前にワイヤー２４と電極２８が干渉し、ワイヤー
２４を引っ張ってばね２５が伸びる。さらに、ばね２５
が伸びたことを検出できるようにセンサー２７が設置さ
れているから、加工槽１１と電極２８が干渉する前に昇
降式加工槽１１の上部に設置されたワイヤーと電極が接
触し、ワイヤーを引っ張って近接センサーの出力が変化
し、制御装置に信号を送って加工槽１１と電極が接触し
て電極が破損する前に昇降式加工槽１１を安全に停止す
ることができる。FIG. 1 is a sectional view of the electric discharge machine shown in FIG.
FIG. A block 23 is provided at an upper corner of a wall surface 22 of the processing tank 11, and one end of a wire 24 is fixed to the block 23. A wire 24 having one end fixed to the block 23 is separated from a spring 25 by a metal plate 26 at the other end while maintaining a distance parallel to the upper side of the wall surface 22 of the processing tank 11.
The tension is applied to the other corner of the wall surface 22 of the processing tank 11. A proximity sensor 27 is mounted near the metal plate 26. The position where the wire 24 is attached is such that the electrode 28 set in the magazine of the automatic electrode changer at the top of the processing tank 11
The position of the proximity sensor 27 is a position on the trajectory that may interfere with the
When the plate 26 moves in the direction of the arrow in FIG. 1 against the tension of the plate 26, the plate 26 is installed at a position where the movement can be detected. Further, the spring constant of the spring 25 is such that the wire 24 comes into contact with the electrode 28 set in the magazine 21 of the automatic electrode changing device, and the spring 25 extends before the electrode 28 is broken when the wire 24 is pulled, The plate 26 is set to be weak enough to be displaced out of the detection range of the proximity sensor 27. In the electric discharge machine configured as described above, the wire 24 and the electrode 28 interfere with each other before the electrode 28 set in the magazine 21 of the automatic electrode changing device and the wall surface 22 on the upper part of the elevating type machining tank 11 interfere with each other. The spring 24 is extended by pulling the wire 24. Further, the spring 25
Since the sensor 27 is installed so as to detect the extension of the wire, the electrode and the wire installed on the upper part of the elevating type processing tank 11 come into contact with each other before the processing tank 11 and the electrode 28 interfere with each other, and the wire is pulled. As a result, the output of the proximity sensor changes, a signal is sent to the control device, and the lifting / lowering type processing tank 11 can be safely stopped before the electrode contacts the processing tank 11 and breaks.

【０００９】[0009]

【発明の効果】上記構成より明らかなように、本願発明
においては、自動電極交換装置のマガジンにセットされ
た電極が例えば大きく、目視により衝突を予測ができず
に昇降式加工槽を上昇させた場合に、加工槽と交換され
た大きな電極とが干渉するようなときでも、加工槽と電
極が干渉する前に昇降式加工槽の上部に設置された検出
手段と電極が接触し、検出手段が制御装置に信号を送る
ので、加工槽と電極が接触して電極が破損する前に昇降
式加工槽を安全に停止することができる。また、実施の
形態のように電極と加工槽との干渉を検出する検出手段
が、加工槽の上部にワイヤーを張設し、そのワイヤーの
端部に近接センサーを取り付けるものである場合、前記
衝突を未然に回避できる効果に加え、簡単な構成で検出
手段を低コストで取り付けることができ、張設されてい
るワイヤーを目視点検の目安にして段取り替えを素早く
行うこともできる。As is evident from the above configuration, in the present invention, the electrode set in the magazine of the automatic electrode changing device is large, for example, and the vertical machining tank is raised without being able to visually predict a collision. In such a case, even when the processing tank and the replaced large electrode interfere with each other, before the processing tank and the electrode interfere with each other, the electrode comes into contact with the detection means installed on the upper part of the elevating processing tank, and the detection means Since the signal is sent to the control device, the lifting / lowering type processing tank can be safely stopped before the electrode is damaged due to the contact between the processing tank and the electrode. In the case where the detecting means for detecting interference between the electrode and the processing tank stretches a wire over the processing tank and attaches a proximity sensor to an end of the wire as in the embodiment, In addition to the effect of obviating the problem, the detecting means can be attached at a low cost with a simple configuration, and the setup can be quickly changed using the stretched wire as a guide for visual inspection.

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

【図１】本願発明に係る昇降式加工槽を持つ放電加工機
の概念的な説明図である。FIG. 1 is a conceptual explanatory view of an electric discharge machine having a vertically movable machining tank according to the present invention.

【図２】昇降式加工槽と自動電極交換装置を持つ放電加
工機の平面図である。FIG. 2 is a plan view of an electric discharge machine having a vertically movable machining tank and an automatic electrode changing device.

【図３】図３の放電加工機におけるＡ−Ａ線断面図であ
る。FIG. 3 is a sectional view taken along line AA in the electric discharge machine of FIG. 3;

【符号の説明】[Explanation of symbols]

１・・加工物、２・・テーブル、３・・ベッド、４・・
Ｘ軸ガイド、５・・サドル、６・・Ｙ軸ガイド、７・・
コラム、８・・Ｚ軸ガイド、９・・ヘッド、１０・・電
極、１１・・加工槽、１３・・加工液供給ポンプ、１４
・・フィルター、１５・・加工液タンク、１６・・加工
液冷却装置、１７・・オーバーフロー穴、１８・・サー
ボモーター、１９・・ボールネジ、２０・・自動交換チ
ャック、２１・・マガジン、２２・・加工槽の壁面、２
３・・ブロック、２４・・ワイヤー、２５・・ばね、２
６・・プレート、２７・・近接センサー。1. Workpiece, 2. Table, 3. Bed, 4.
X axis guide, 5 ... saddle, 6 ... Y axis guide, 7 ...
Column, 8 ·· Z axis guide, 9 · head, 10 · electrode, 11 · working tank, 13 · working fluid supply pump, 14
··· Filter, 15 ·· Work fluid tank, 16 ·· Work fluid cooling device, 17 ·· Overflow hole, 18 ·· Servo motor, 19 ·· Ball screw, 20 ·· Automatic exchange chuck, 21 ·· Magazine, 22 ·・ Wall surface of processing tank, 2
3 blocks, 24 wires, 25 springs, 2
6. Plate, 27. Proximity sensor.

Claims (1)

【特許請求の範囲】[Claims] 【請求項１】 テーブルに固定された加工物に放電をす
る電極と、加工物に対し昇降可能で、溜めた放電加工液
に加工物を浸漬可能な加工槽と、電極を別の電極に交換
する自動電極交換装置と、自動電極交換装置により交換
される電極及び別の電極を収納するマガジンとを備える
放電加工機において、加工槽壁面の上部に、電極と昇降
する加工槽との干渉を検出する検出手段を備える放電加
工機。1. An electrode which discharges a workpiece fixed to a table, a machining tank which can be raised and lowered with respect to the workpiece and which can immerse the workpiece in a stored electric discharge machining fluid, and replaces the electrode with another electrode. In an electric discharge machine equipped with an automatic electrode changer that performs the operation and a magazine that stores the electrodes to be exchanged by the automatic electrode changer and another electrode, the interference between the electrode and the ascending and descending machining tank is detected at the top of the machining tank wall. EDM equipped with a detecting means for detecting the electric discharge.