JPH0346245B2 - - Google Patents
Info
- Publication number
- JPH0346245B2 JPH0346245B2 JP57071022A JP7102282A JPH0346245B2 JP H0346245 B2 JPH0346245 B2 JP H0346245B2 JP 57071022 A JP57071022 A JP 57071022A JP 7102282 A JP7102282 A JP 7102282A JP H0346245 B2 JPH0346245 B2 JP H0346245B2
- Authority
- JP
- Japan
- Prior art keywords
- electrode
- electrode materials
- workpiece
- large number
- machining
- 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
Links
- 239000007772 electrode material Substances 0.000 claims description 43
- 238000009760 electrical discharge machining Methods 0.000 claims description 13
- 238000000034 method Methods 0.000 claims description 10
- 238000009413 insulation Methods 0.000 claims 2
- 238000003754 machining Methods 0.000 description 29
- 238000010586 diagram Methods 0.000 description 13
- 239000012212 insulator Substances 0.000 description 4
- 230000003746 surface roughness Effects 0.000 description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 2
- 239000003990 capacitor Substances 0.000 description 2
- 229910052802 copper Inorganic materials 0.000 description 2
- 239000010949 copper Substances 0.000 description 2
- 238000010891 electric arc Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 229910002804 graphite Inorganic materials 0.000 description 2
- 239000010439 graphite Substances 0.000 description 2
- 238000003672 processing method Methods 0.000 description 2
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000011049 filling Methods 0.000 description 1
- 239000003350 kerosene Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 238000007747 plating Methods 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
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
- B23H1/04—Electrodes specially adapted therefor or their manufacture
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Mechanical Engineering (AREA)
- Electrical Discharge Machining, Electrochemical Machining, And Combined Machining (AREA)
Description
【発明の詳細な説明】
この発明は、三次元形状の自由曲面を含む金型
等の加工面に放電加工を用いて鏡面加工を施す放
電加工装置及び加工方法に関するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electric discharge machining apparatus and a machining method for mirror-finishing a machining surface of a mold or the like including a three-dimensional free-form surface using electric discharge machining.
近時、金型加工の無人化の研究が行われている
が、金型表面の鏡面仕上に関しては主として回転
砥石車を使用するものが多く、例えば三次元形状
の加工には砥石形状、寸法による制約が多くあ
る。そこで、放電加工を用いて鏡面加工を行うこ
とが試みられるようになりつつある。 Recently, research has been carried out on unmanned mold machining, but in order to achieve a mirror finish on the surface of molds, many use mainly rotary grinding wheels.For example, when machining three-dimensional shapes, it is necessary to There are many restrictions. Therefore, attempts are being made to perform mirror finishing using electrical discharge machining.
ところで、これまでの放電加工技術による鏡面
加工においては、10cm2程度以下の小面積でのみ可
能であり、これにも例えば10cm2で20〜30時間もの
長時間を要するのが常態で、加工面積が実用的な
金型の広い面積(例えば100〜1000cm2)になると、
いくら時間をかけて加工しても鏡面(0.4μm
Rmax以下)を得ることが困難となる現状であ
る。 By the way, mirror finishing using conventional electrical discharge machining technology is only possible on small areas of about 10 cm 2 or less, and it usually takes a long time, for example, 20 to 30 hours to process 10 cm 2 . When it comes to a large area of practical mold (e.g. 100-1000cm2 ),
No matter how much time it takes to process the mirror surface (0.4μm)
The current situation is that it is difficult to obtain Rmax (lower than Rmax).
第1図は、通常の放電加工装置の一例を示すも
ので、この図において、1は放電加工用電極で、
被加工物2と加工間〓を介して相対向して白灯油
のような絶縁性加工媒体の中に浸漬されている。
3A,3B…3Nは、加工間〓に流される放電電
流を断続して方形波パルスを発生させる複数個の
トランジスタで、互いに並列に接続されている。
このトランジスタ群は、放電電流が小さい場合に
はその個数は少なくてよく、例えば1個のトラン
ジスタでもよい。4A,4B…4Nはトランジス
タのコレクタ電流を定格内におさえる共に、電流
をバランスさせるための抵抗、5A,5B…5N
は各トランジスタのベース電流を制限するベース
抵抗、6はパルス発生回路からなる時間計数回路
で、無安定マルチバイブレータ、単安定マルチバ
イブレータ、フリツプフロツプ回路等で構成され
ている。7は増幅器で、時間計数回路6で発生さ
せたパルスを増幅し、トランジスタ3A,3B…
3Nに与えるものである。なお、Epは加工電源を
示している。 Figure 1 shows an example of a normal electrical discharge machining device. In this figure, 1 is an electrode for electrical discharge machining;
The workpiece 2 and the workpiece 2 are immersed in an insulating processing medium such as white kerosene, facing each other with a gap between them.
3A, 3B, . . . , 3N are a plurality of transistors that generate square wave pulses by intermittent discharge current flowing during machining, and are connected in parallel to each other.
This transistor group may be small in number if the discharge current is small; for example, it may be one transistor. 4A, 4B...4N are resistors to keep the collector current of the transistor within the rating and balance the current, 5A, 5B...5N
6 is a base resistor that limits the base current of each transistor, and 6 is a time counting circuit consisting of a pulse generating circuit, which is composed of an astable multivibrator, a monostable multivibrator, a flip-flop circuit, etc. 7 is an amplifier which amplifies the pulse generated by the time counting circuit 6, and transistors 3A, 3B...
It is given to 3N. Note that E p indicates a processing power source.
第2図のa,bは、第1図に示す装置によつて
加工間隙に印加される電圧及び電流波形を示す図
で、図中τpは電圧パルス幅、τrは休止幅、τNは無
負荷電圧印加時間、τHは放電持続時間、8は無負
荷電圧、9は放電電圧、10は放電電流、Ipは放
電電流ピーク値、IRは平均加工電流を夫々示して
いる。 Figures a and b in Figure 2 are diagrams showing the voltage and current waveforms applied to the machining gap by the device shown in Figure 1, where τp is the voltage pulse width, τr is the pause width, and τN is the null value. The load voltage application time, τ H is the discharge duration, 8 is the no-load voltage, 9 is the discharge voltage, 10 is the discharge current, Ip is the discharge current peak value, and I R is the average machining current.
ここで加工仕上面は、放電電流ピーク値Ipと、
放電持続時間τHを小さくすればする程次第に精細
になつて行くが、放電電流ピーク値Ipと放電持続
時間τHをどんなに小さくしても加工面が鏡面とな
らない限界が存在する。 Here, the machined surface is the discharge current peak value Ip,
The smaller the discharge duration τ H is, the finer the process becomes, but no matter how small the discharge current peak value Ip and the discharge duration τ H are, there is a limit at which the machined surface will not become a mirror surface.
そこで、本発明者達は、この限界の存在する理
由について種々の実験と考察から次の事項に起因
することを見出した。 The inventors of the present invention have found from various experiments and considerations that the reason for the existence of this limit is as follows.
即ち、第1の理由は、第3図aに等価的に示す
ように、加工間〓には加工電源Epや機械装置(図
示せず)が本来持つている浮遊静電容量C0が存
在するために、放電電流ピーク値Ipと放電持続時
間τH、即ち投入電力を小さくしても浮遊静電容量
C0に電荷が蓄積され、この蓄積された電荷が放
電するため、第3図bに示すコンデンサ放電の大
電流によつて加工面が荒らされるためである。こ
れを具体的数値をもつて更に説明すれば、今、放
電電圧Ed(V)、極間アーク電圧(放電時の極間
電圧)eg(V)、回路のインダクタンスL(μH)、
加工間〓に作用する静電容量C0(μF)とすれば、
コンデンサ放電ピーク電流Ipは、
Ip≒(Ed−eg)/√ ……(1)
で表わされ、又、放電持続時間τHは、
τH≒π√ ……(2)
で表わされる。 That is, the first reason is that, as equivalently shown in Fig. 3a, there is a stray capacitance C 0 that is inherent to the processing power source E p and mechanical equipment (not shown) between the processing lines. In order to
This is because charge is accumulated in C 0 and the accumulated charge is discharged, so that the machined surface is roughened by the large current of the capacitor discharge shown in FIG. 3b. To further explain this with specific numerical values, we now have the following: discharge voltage Ed (V), arc voltage between electrodes (voltage between electrodes during discharge) eg (V), circuit inductance L (μH),
If the capacitance acting during machining is C 0 (μF), then
The capacitor discharge peak current Ip is expressed as Ip≒(Ed-eg)/√...(1), and the discharge duration τH is expressed as τH ≒π√...(2).
ここで、通常放電電圧Edは加工電源で定まり
80〜100(V)、極間アーク電圧egは電極と被加工
物の材料の組合せで定まり、銅対ステンレススチ
ールの場合は20(V)程度、回路のインダクタン
スLは通常0.2(μH)程度であるから、静電容量
Cpを0.01(μH)程度としても、(1)式及び(2)式か
ら、Ip≒29(A)、τH≒0.14(μS)が算出される。そ
して、この程度の仕上面粗さは、3〜4μmRmax
となり、鏡面にはほど遠い粗さである。 Here, the normal discharge voltage Ed is determined by the machining power source.
80 to 100 (V), arc voltage eg between electrodes is determined by the combination of electrode and workpiece material, about 20 (V) in the case of copper versus stainless steel, and circuit inductance L is usually about 0.2 (μH). Because there is capacitance
Even if C p is about 0.01 (μH), Ip≒29 (A) and τ H ≈0.14 (μS) are calculated from equations (1) and (2). The finished surface roughness of this level is 3 to 4 μmRmax.
The surface roughness is far from mirror-like.
なお、加工電源E0や機械装置が本来もつてい
る浮遊静電容量C0としては、0.01(μH)程度は存
在するものである。 It should be noted that the stray capacitance C 0 inherent in the machining power source E 0 and mechanical equipment is approximately 0.01 (μH).
また、第2の理由は、第4図に示すように、電
極1と被加工物2との対向面積による静電容量CS
が、被加工物2の加工の際に上述の第1の理由に
おいて説明した浮遊静電容量C0に重畳して作用
することである。 The second reason is the capacitance C S due to the opposing area between the electrode 1 and the workpiece 2, as shown in FIG.
However, when processing the workpiece 2, it acts superimposed on the stray capacitance C 0 explained in the above-mentioned first reason.
即ち、第4図において、電極1と被加工物2の
対向面積をScm2、対向面間距離をdcm、加工媒体
11の誘電率をεとすれば、電極1と被加工物2
との対向面積による静電容量Csは周知のように、
Cs=ε・S/d ……(3)
で表され、これにより被加工物2の加工面が影響
をうけることである。 That is, in FIG. 4, if the opposing area of the electrode 1 and the workpiece 2 is Scm 2 , the distance between the opposing surfaces is dcm, and the dielectric constant of the processing medium 11 is ε, then the electrode 1 and the workpiece 2 are
As is well known, the capacitance Cs due to the area facing the workpiece 2 is expressed as Cs=ε·S/d (3), and this affects the machined surface of the workpiece 2.
以上のように、浮遊静電容量C0と電極1と被
加工物2との対向面積による静電容量Csが重畳
して作用するため、加工面積が実用的な金型の広
い面積になると、放電電流ピーク値Ipと放電持続
時間τHをいくら小さくしても加工面に鏡面が得ら
れないことが判明した。 As mentioned above, since the stray capacitance C 0 and the capacitance Cs due to the opposing area between the electrode 1 and the workpiece 2 act in a superimposed manner, when the processing area becomes a large area of a practical mold, It was found that no matter how small the discharge current peak value Ip and the discharge duration τ H were, a mirror surface could not be obtained on the machined surface.
この発明は、このような実験結果及びその考察
から、上述の第2の理由に基ずきなされたもので
あつて、加工面積が実用的な金型の広い面積であ
つても鏡面が得られる鏡面加工用電極を有する放
電加工装置及び加工方法を提供することを目的と
する。 This invention was made based on the above-mentioned second reason from such experimental results and considerations, and it is possible to obtain a mirror surface even if the processing area is a large area of a practical mold. It is an object of the present invention to provide an electric discharge machining device and a machining method having an electrode for mirror finishing.
以下、この発明の一実施例について図面ととも
に詳説する。即ち、第5図は、この発明による放
電加工装置の概略構成図で、図において、50は
加工槽、51は加工槽50内に設置される電気的
絶縁基台、52は基台51上に載置される被加工
物、53は被加工物52と加工媒体54を介して
対向する電極、55は電極53と被加工物52間
に加工エネルギーを供給する加工電源で、この加
工電源55は高周波パルス電源とこの高周波パル
ス電源からの高周波パルス(例えば2MHz程度)
を整流する整流装置を包含する。56は電極53
に後述するように主軸送りに加えて揺動運動を与
える電極送り装置である。 Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings. That is, FIG. 5 is a schematic configuration diagram of the electrical discharge machining apparatus according to the present invention. In the figure, 50 is a machining tank, 51 is an electrically insulating base installed in the machining tank 50, and 52 is an electrically insulating base installed on the base 51. The workpiece to be placed, 53 is an electrode that faces the workpiece 52 via the processing medium 54, 55 is a processing power source that supplies processing energy between the electrode 53 and the workpiece 52, and this processing power source 55 is High-frequency pulse power supply and high-frequency pulses from this high-frequency pulse power supply (for example, about 2MHz)
It includes a rectifier that rectifies. 56 is an electrode 53
As will be described later, this is an electrode feeding device that provides oscillating motion in addition to main shaft feeding.
又、電極53は次のように構成されている。即
ち、57a〜57nは一辺が10mm程度の銅または
グラフアイトの角棒、六角棒、丸棒等の電極素
材、58a〜58n−1は電極素材57a〜57
n間を互いに電気的に絶縁する絶縁体、59a〜
59nは電極素材57a〜57nに一端が夫々接
続され、他端が集電板60に接続される電流制限
体、例えば抵抗体、61は電極素材57a〜57
nを結束する結束手段、例えばホルダーであり、
電流制限体59a〜59nは集電板60とホルダ
ー61との内側に収納されている。また、gは電
極素材57a〜57n間の〓間を示している。な
お、電極素材57a〜57nが金属の場合には、
盛り金や溶接あるいはメツキ法により絶縁体58
a〜58n−1を介して電極素材57a〜57n
を接着してもよく、電極素材57a〜57nがグ
ラフアイトの場合には、同様に絶縁体58a〜5
8n−1を介して電極素材57a〜57nを導電
性接着剤などで接着して一体化してもよい。 Further, the electrode 53 is configured as follows. That is, 57a to 57n are electrode materials such as square rods, hexagonal rods, and round rods made of copper or graphite with a side of about 10 mm, and 58a to 58n-1 are electrode materials 57a to 57.
an insulator that electrically insulates n from each other, 59a~
Reference numeral 59n indicates a current limiting body, for example, a resistor, which has one end connected to each of the electrode materials 57a to 57n and the other end to the current collector plate 60, and 61 indicates a current limiter connected to the electrode materials 57a to 57.
A binding means for binding n, such as a holder,
The current limiters 59a to 59n are housed inside the current collector plate 60 and the holder 61. Further, g indicates the distance between the electrode materials 57a to 57n. Note that when the electrode materials 57a to 57n are metal,
The insulator 58 is formed by filling, welding, or plating.
Electrode materials 57a to 57n via a to 58n-1
If the electrode materials 57a to 57n are graphite, the insulators 58a to 5 may be bonded together.
The electrode materials 57a to 57n may be bonded together using a conductive adhesive or the like via the electrode material 8n-1.
次に、ここで電流制限体59a〜59nの作用
について説明する。 Next, the action of the current limiters 59a to 59n will be explained here.
この電流制限体58a〜59nは、後述するよ
うに、例えば電極素材57aと被加工物52間に
放電が発生した場合、前述のように他の電極素材
57b〜57nと被加工物52間の夫々に形成さ
れる静電容量CSに蓄積された電荷が、電極素材5
7aと被加工物52間の放電に合流するのを阻止
することと、加工電源55からの電流を限流して
電極素材57aの放電箇所に加工電源55からの
電流が集中するのを防止する、換言すれば、各電
極素材57a〜57nへの最大電流を制限する作
用を成している。 These current limiters 58a to 59n, as described later, are used to control the current between the other electrode materials 57b to 57n and the workpiece 52, as described above, when an electric discharge occurs between the electrode material 57a and the workpiece 52, for example. The charge accumulated in the capacitance C S formed in the electrode material 5
7a and the workpiece 52, and limit the current from the machining power source 55 to prevent the current from the machining power source 55 from concentrating on the discharge location of the electrode material 57a. In other words, it functions to limit the maximum current flowing to each electrode material 57a to 57n.
以上が装置の概略構成であるが、次に加工方法
を詳説する。即ち、第6図は加工方法を説明する
ための斜視図であつて、この図のZ軸方向への主
軸送りに加えて、多数の電極素材を束ねて構成す
る電極構造に基困して生ずる加工面における残留
芯及び加工側面の残留条痕を取り除くため、電極
53の偏心運動と揺動運動とを行わせて加工する
のであるが、先ずZ軸方向への主軸送りについて
説明する。 The above is the general configuration of the apparatus, and next, the processing method will be explained in detail. That is, FIG. 6 is a perspective view for explaining the processing method, and in addition to the main shaft feeding in the Z-axis direction shown in this figure, there is a problem that occurs due to the electrode structure consisting of a large number of electrode materials bundled together. In order to remove the residual core on the machining surface and the residual striations on the machining side surface, machining is performed by performing eccentric movement and rocking motion of the electrode 53. First, the main spindle feeding in the Z-axis direction will be explained.
放電は電極素材57a〜57nと被加工物52
間で発生するわけであるが、短絡あるいはアーク
が頻発しない範囲で、電極53の送りが最大にな
るようにサーボする。即ち、第7図示す放電電圧
波形を検出することにより、正常状態、短絡状
態、アーク状態を判別し、短絡あるいはアーク放
電が所定時間内(例えば1秒間)に発生する数を
計数し、この計数値と基準値を比較して短絡ある
いはアーク放電の頻度が多ければ送り速度を小さ
く制御し、少なければ送り速度を大きく制御す
る。尤も、通常行われている加工間〓の平均電圧
を検出し、これを基準電圧に等しくするように電
極53の送りを制御する方式を採用してもよい。 The discharge occurs between the electrode materials 57a to 57n and the workpiece 52.
However, the servo is operated so that the feed of the electrode 53 is maximized within a range where short circuits or arcs do not occur frequently. That is, by detecting the discharge voltage waveform shown in Figure 7, a normal state, a short circuit state, and an arc state are determined, and the number of short circuits or arc discharges that occur within a predetermined period of time (for example, 1 second) is counted, and this total is calculated. The numerical value is compared with the reference value, and if the frequency of short circuits or arc discharges is high, the feed speed is controlled to be low, and if it is low, the feed speed is controlled to be high. Of course, a method may also be adopted in which the average voltage during the machining process that is normally performed is detected and the feed of the electrode 53 is controlled so as to make this equal to the reference voltage.
次に、電極53の偏心運動と揺動運動とについ
て説明する。 Next, the eccentric movement and rocking movement of the electrode 53 will be explained.
即ち、62は基準点0を中心とする偏心運動
で、この運動は電極53に回転を与えるものでは
なく、X軸、Y軸に関する方向は変わらない。6
3及び64はX軸及びY軸における揺動運動で、
この運動はX−Z軸及びY−Z軸に関して円弧を
含んで往復運動をするよう制御するものである。 That is, 62 is an eccentric movement about the reference point 0, and this movement does not give rotation to the electrode 53, and the directions regarding the X-axis and Y-axis do not change. 6
3 and 64 are rocking movements on the X and Y axes,
This movement is controlled to perform reciprocating motion including circular arcs with respect to the X-Z axis and the Y-Z axis.
一般に、加工底面における残留芯及び加工側面
における電極素材57a〜57nの側面による残
留条痕は少なくとも電極素材57a〜57nの直
径に等しい偏心量の偏心運動62によつて取除く
ことができる。しかしながら、第6図に示すよう
に、側面に傾斜を持つ電極53によつて被加工物
52を形成する場合には、電極素材57a〜57
nの段差による残留条痕は偏心運動62だけでは
取除くことができず、電極53に揺動運動63及
び64を与えることが必要である。なお、球状の
側面を持つ電極の場合には、揺動運動63及び6
4は、X−Z軸、Y−Z軸のみではなく、その中
間も含め全周にわたつて細分化して行われるのが
よい。実用上は円周を8等分または16等分して揺
動運動を行えば円滑な面となる。 Generally, the residual core on the bottom surface of the process and the residual streaks on the side surfaces of the electrode materials 57a to 57n can be removed by eccentric movement 62 having an eccentric amount at least equal to the diameter of the electrode materials 57a to 57n. However, as shown in FIG. 6, when forming the workpiece 52 with the electrode 53 having an inclined side surface,
The residual striations due to the n steps cannot be removed by eccentric movement 62 alone, and it is necessary to apply rocking movements 63 and 64 to electrode 53. Note that in the case of electrodes with spherical side surfaces, the rocking movements 63 and 6
4 is preferably performed by subdividing not only the X-Z axis and the Y-Z axis, but also the entire circumference including the intermediate area. In practical terms, a smooth surface can be obtained by dividing the circumference into 8 or 16 equal parts and performing rocking motion.
次に、電極53に用いられる電極素材及び偏心
量、揺動量と仕上面あらさとの関係について説明
する。 Next, the relationship between the electrode material used for the electrode 53, the amount of eccentricity, the amount of rocking, and the roughness of the finished surface will be explained.
偏心運動については、通常、棒やパイプなどの
直径に相当する寸法の偏心量とすれば、残留芯は
全て取除くことができるし、側面の残留条痕もほ
ぼ直線あるいは所望する曲線に近似させることが
できる。従つて、偏心量を小さくしようとすれば
棒やパイプなどの径の小さいものを使用したほう
がよいこといなる。 Regarding eccentric movement, if the amount of eccentricity is equivalent to the diameter of the rod or pipe, all the remaining core can be removed, and the remaining streaks on the sides can be approximated to a nearly straight line or a desired curve. be able to. Therefore, in order to reduce the amount of eccentricity, it is better to use rods, pipes, etc. with small diameters.
また、揺動運動については、通常、棒やパイプ
などの径と側面の傾斜によつて定まる段差とで決
まる。第8図は、電極の揺動運動によつて形成さ
れる仕上面の側断面形状を示すもので、Rは電極
53の揺動運動63の揺動半径、dは電極素材5
7a〜57nの直径、hは電極側面の段差の高
さ、Sは電極素材57a〜57nの直径dと段差
の高さhとによつて、
S=√2+2 ……(4)
で与えられる段差ピツチである。今、第9図に示
すように、加工面の最大あらさHmaxは段差ピツ
チSが揺動半径Rの2倍より大きい場合、即ち
S>2Rの場合には
S2/8R<Hmax<d ……(5)
となり、第10図に示すように、段差ピツチSが
揺動半径Rの2倍より小さい場合、即ち
S<2Rの場合には
Hmax≒d ……(6)
となる。従つて、仕上面あらさHmaxは、(4)、
(5)、(6)式からわかるように、電極素材57a〜5
7nの直径dが小さい程、段差の高さhが小さい
程、又、揺動半径Rが大きい程良好な仕上面を得
ることができる。 Further, the rocking motion is usually determined by the diameter of the rod or pipe and the step determined by the slope of the side surface. FIG. 8 shows the side cross-sectional shape of the finished surface formed by the rocking motion of the electrode, where R is the rocking radius of the rocking motion 63 of the electrode 53, and d is the electrode material 5.
The diameter of the electrodes 7a to 57n, h is the height of the step on the side surface of the electrode, and S is the diameter d of the electrode material 57a to 57n and the height of the step h, given by S=√ 2 + 2 ...(4) This is a level difference pitch. Now, as shown in Fig. 9, the maximum roughness Hmax of the machined surface is S 2 /8R<Hmax<d when the step pitch S is larger than twice the swing radius R, that is, when S>2R. (5), and as shown in FIG. 10, when the step pitch S is smaller than twice the swing radius R, that is, when S<2R, Hmax≒d...(6). Therefore, the finished surface roughness Hmax is (4),
As can be seen from equations (5) and (6), the electrode materials 57a to 5
The smaller the diameter d of 7n, the smaller the height h of the step, and the larger the swing radius R, the better the finished surface can be obtained.
発明者達の実験結果によれば、断面席0.5cm2の
棒状電極素材を使用して、1000cm2の加工面を加工
するのに2000本程度(〓間gに相当する分の電極
素材は少なくなる)の集合体として電極53を構
成して加工した場合、加工電気条件にもよるが1
〜9時間で鏡面が得られることが判明している。 According to the inventors' experimental results, using rod-shaped electrode material with a cross-sectional area of 0.5 cm 2 , approximately 2000 electrodes are used to process a surface of 1000 cm 2 (the electrode material corresponding to the distance g is small). If the electrode 53 is constructed and processed as a collection of
It has been found that a mirror surface can be obtained in ~9 hours.
又、第11図は、この発明の他の実施例を示す
もので、加工電源55の一方の極と電極素材57
a〜57n間にトランジスタ65a〜65nと抵
抗体59a〜59nの直列体を接続したもので、
これによれば例えば電極素材57aと被加工物5
2間で放電が発生した場合、他の電極素材57b
〜57nと被加工物52間の夫々で形成される静
電容量Csに蓄積される電荷が、電極素材57a
と被加工物52の放電に全く関与しなくなり、一
層良好な鏡面加工が可能となる。 Further, FIG. 11 shows another embodiment of the present invention, in which one pole of the processing power source 55 and the electrode material 57 are connected.
A series body of transistors 65a to 65n and resistors 59a to 59n is connected between a to 57n,
According to this, for example, the electrode material 57a and the workpiece 5
If a discharge occurs between 2, another electrode material 57b
The electric charge accumulated in the capacitance Cs formed between the electrode material 57n and the workpiece 52 is transferred to the electrode material 57a.
This eliminates any involvement in the electrical discharge of the workpiece 52, making it possible to perform even better mirror finishing.
なお、トランジスタ65a〜65nはダイオー
ドに置換えてもよく、その他の一方向導通素子で
あつても同等の効果が得られる。 Note that the transistors 65a to 65n may be replaced with diodes, and the same effect can be obtained even if other unidirectional conduction elements are used.
以上この発明によれば、電流制限体を集電体及
び結束手段内に収納しているので放電加工用電極
をコンパクトにした放電加工装置が得られると共
に、多数の電極素材が絶縁手段と共に結束手段に
より結束されているので電極が露出せず安全且つ
作業性の向上が図れる放電加工装置が得られ、従
来技術では不可能とされていた加工面積が実用的
な広さにおいて放電による鏡面加工を可能とし、
その加工時間も短縮できて、放電による金型の鏡
面加工の実用化に大きく寄与するものである。 As described above, according to the present invention, since the current limiter is housed within the current collector and the binding means, it is possible to obtain an electrical discharge machining apparatus in which the electrode for electrical discharge machining is made compact, and a large number of electrode materials are housed in the binding means together with the insulating means. Since the electrodes are bundled together, an electric discharge machining device that is safe and improves workability without exposing the electrodes can be obtained, and mirror surface machining by electric discharge is possible in a practical area with a machining area that was considered impossible with conventional technology. year,
The machining time can also be shortened, and this will greatly contribute to the practical application of mirror finishing of molds using electrical discharge.
第1図は一般の放電加工装置を示す構成図、第
2図は第1図の装置による放電電圧波形及び放電
電流波形を示す図、第3図は放電加工装置に存在
する浮遊静電容量を説明する等価図及びその放電
電圧、放電電流波形図、第4図は電極と被加工物
の対向間〓に存在する静電容量を説明する図、第
5図はこの発明による放電加工装置に使用する電
極構成を示す概略構成図、第6図はこの発明によ
る放電加工装置での加工方法の一実施例を説明す
るための図、第7図は電極送りを説明するための
放電電圧波形図、第8図は電極の揺動運動によつ
て加工される仕上面の側断面図、第9図は第8図
における段差ピツチが揺動半径の2倍より大きい
場合の説明図、第10図は第8図おける段差ピツ
チが揺動半径の2倍より小さい場合の説明図、第
11図はこの発明による放電加工装置の他の実施
例を示す図である。
図において、1,53は電極、2,52は被加
工物、51は電気的絶縁基台、58a〜58nは
絶縁体、57a〜57nは電極素材、59a〜5
9nは電流制限体、60は集電板、64はホルダ
ー、65〜65nはトランジスタである。なお、
図中同一符号は同一又は相当部分を示している。
Fig. 1 is a configuration diagram showing a general electrical discharge machining device, Fig. 2 is a diagram showing the discharge voltage waveform and discharge current waveform by the device in Fig. 1, and Fig. 3 shows the stray capacitance existing in the electrical discharge machining device. An equivalent diagram to be explained and its discharge voltage and discharge current waveform diagram; Figure 4 is a diagram to explain the capacitance existing between the electrode and the workpiece facing each other; Figure 5 is a diagram used in the electric discharge machining apparatus according to the present invention. 6 is a diagram for explaining an embodiment of the machining method in the electrical discharge machining apparatus according to the present invention; FIG. 7 is a discharge voltage waveform diagram for explaining electrode feeding; Fig. 8 is a side sectional view of the finished surface machined by the oscillating motion of the electrode, Fig. 9 is an explanatory diagram when the step pitch in Fig. 8 is larger than twice the oscillating radius, and Fig. 10 is FIG. 8 is an explanatory diagram of the case where the step pitch is smaller than twice the swing radius, and FIG. 11 is a diagram showing another embodiment of the electric discharge machining apparatus according to the present invention. In the figure, 1 and 53 are electrodes, 2 and 52 are workpieces, 51 is an electrically insulating base, 58a to 58n are insulators, 57a to 57n are electrode materials, and 59a to 5
9n is a current limiter, 60 is a current collector plate, 64 is a holder, and 65 to 65n are transistors. In addition,
The same reference numerals in the figures indicate the same or corresponding parts.
Claims (1)
する結束手段と、 この結束手段に取り付けられ上記多数の電極素
材に接続される集電体と、 上記集電体と上記多数の電極素材の夫々との間
に直列的に接続構成され上記集電体及び結束手段
内に収納された電流制限体と、 を備えた放電加工用電極を有することを特徴とす
る放電加工装置。 2 多数の電極素材と、 この多数の電極素材を互いに絶縁する手段と、 上記多数の電極素材を上記絶縁手段と共に結束
する結束手段と、 この結束手段に取り付けられ上記多数の電極素
材に接続される集電体と、 上記集電体と上記多数の電極素材の夫々との間
に直列的に接続構成され上記集電体及び結束手段
内に収納された電流制限体と、 を備えた放電加工用電極を、被加工物と対向さ
せ、この対向方向に相対移動させる主軸送り方向
と交差する面で基準点を中心とする偏心運動又は
球面運動を与えながら上記被加工物を加工するこ
とを特徴とする放電加工方法。[Claims] 1. A large number of electrode materials, means for insulating the large number of electrode materials from each other, binding means for binding the large number of electrode materials together with the insulation means, and a large number of the electrode materials attached to the binding means. a current collector connected to an electrode material; a current limiter configured to be connected in series between the current collector and each of the plurality of electrode materials and housed in the current collector and the binding means; An electrical discharge machining device characterized by having an electrode for electrical discharge machining. 2. A large number of electrode materials, means for insulating the large number of electrode materials from each other, binding means for binding the large number of electrode materials together with the insulation means, and a device attached to the binding means and connected to the large number of electrode materials. A current collector; and a current limiter configured to be connected in series between the current collector and each of the plurality of electrode materials and housed in the current collector and the binding means. The workpiece is machined while the electrode is placed opposite to the workpiece and is moved relative to the workpiece in the opposing direction while giving eccentric motion or spherical motion about a reference point in a plane intersecting the spindle feeding direction. electrical discharge machining method.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP7102282A JPS58186532A (en) | 1982-04-27 | 1982-04-27 | Mirror face machining electrode by electric discharge |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP7102282A JPS58186532A (en) | 1982-04-27 | 1982-04-27 | Mirror face machining electrode by electric discharge |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS58186532A JPS58186532A (en) | 1983-10-31 |
JPH0346245B2 true JPH0346245B2 (en) | 1991-07-15 |
Family
ID=13448476
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP7102282A Granted JPS58186532A (en) | 1982-04-27 | 1982-04-27 | Mirror face machining electrode by electric discharge |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS58186532A (en) |
Families Citing this family (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4937415A (en) * | 1988-01-27 | 1990-06-26 | Hycor Biomedical, Inc. | Examination slide grid system |
JPH09290327A (en) * | 1996-02-27 | 1997-11-11 | Mitsubishi Electric Corp | Electric discharge machining device |
JP3794244B2 (en) | 2000-06-12 | 2006-07-05 | 三菱電機株式会社 | EDM machine |
US6624377B2 (en) * | 2001-06-01 | 2003-09-23 | Wisconsin Alumni Research Foundation | Micro-electro-discharge machining method and apparatus |
US6586699B1 (en) * | 2002-02-20 | 2003-07-01 | Wisconsin Alumni Research Foundation | Micro-electro-discharge machining utilizing semiconductor electrodes |
CN102151922B (en) * | 2010-12-30 | 2012-07-25 | 上海交通大学 | Device and method for quickly manufacturing bundled forming electrode profile |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS54139193A (en) * | 1978-04-20 | 1979-10-29 | Mitsubishi Electric Corp | Electro-processing control method |
JPS5715632A (en) * | 1980-06-26 | 1982-01-27 | Inoue Japax Res Inc | Electric discharge machining method |
-
1982
- 1982-04-27 JP JP7102282A patent/JPS58186532A/en active Granted
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS54139193A (en) * | 1978-04-20 | 1979-10-29 | Mitsubishi Electric Corp | Electro-processing control method |
JPS5715632A (en) * | 1980-06-26 | 1982-01-27 | Inoue Japax Res Inc | Electric discharge machining method |
Also Published As
Publication number | Publication date |
---|---|
JPS58186532A (en) | 1983-10-31 |
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