US3493710A - Electroerosive machining - Google Patents

Electroerosive machining Download PDF

Info

Publication number
US3493710A
US3493710A US553369A US3493710DA US3493710A US 3493710 A US3493710 A US 3493710A US 553369 A US553369 A US 553369A US 3493710D A US3493710D A US 3493710DA US 3493710 A US3493710 A US 3493710A
Authority
US
United States
Prior art keywords
wire
spinneret
oxygen
electrode
rate
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
US553369A
Other languages
English (en)
Inventor
Lloyd M Moore
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.)
Monsanto Co
Original Assignee
Monsanto Co
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 Monsanto Co filed Critical Monsanto Co
Application granted granted Critical
Publication of US3493710A publication Critical patent/US3493710A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

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
    • B23H1/08—Working media
    • 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
    • B23H7/00—Processes or apparatus applicable to both electrical discharge machining and electrochemical machining
    • B23H7/02—Wire-cutting

Definitions

  • FIG. 5. FIG. 6.
  • This invention concerns an electroerosive method of cutting small passages through a workpiece of electrically conductive materials such as metals.
  • the invention relates to an improved method of electroerosively generating non-circular orifices in spinnerets useful for the production of man-made strands having non-circular cross-sections.
  • the physical characteristics of man-made filaments may be greatly altered by changing the cross-sectional shape thereof.
  • the luster, handle, bulk, porosity, and many other properties of fabrics are modified by selecting textile filaments having a specific form of cross-section, such as Y-section, star-section, ribbon section, hollow section, etc.
  • the shape of a synthetic filament cross-section is determined primarily by the shape of the orifices in the spinneret through which the molten polymer or polymer solution is extruded. Under practical spinning conditions the filament section resembles the cross-section of the orifice, although sharp corners or intersections in the orifice tend to be rounded off or merged together in the filament section. To produce filaments having uniformly controlled cross-sections it is necessary, therefore, to provide spinneret capillaries having accurately controlled shapes.
  • capillary refers to the entire passage through the spinneret plate; that is, the three-dimensional form of the passage including both its axial length and its crosssectional shape.
  • Orifice refers to the opening at each end of the capillary and strictly is two-dimensional in connotation.
  • Another method involves the use of conventional twist is u 3 ,493 ,7 l0 Patented Feb. 3, 1970 drills of microdimensions.
  • a row of circular holes are drilled first, and the webs between holes are then punched out or milled out, leaving an open slot.
  • the small circular holes can not be drilled to a depth greater than 5 to 10 times the diameter of the drill so that maximum capillary length is limited thereby.
  • a single hole might extend to the extreme limit of length but duplication of many such holes requires uncommon skill and attention of the worker.
  • Another method of forming orifices utilizes the burning or melting of holes through the spinneret plate by means of a focused beam of accelerated electrons that traces out the contour of the capillary. This method has proven deficient practically. Capillary walls converge (or diverge) from the inlet to the outlet end, and the walls tend to have irregular serrated margins; lateral dimensions also tend to vary excessively from one capillary to another. Because of these uncontrolled dimensional variations and wall irregularities, such spinnerets have poor operating characteristics and resultant yarn properties are too highly variable for general commercial acceptance.
  • the metal spinneret plate is insulated with a thin coating of dielectric material leaving exposed metal in the shape of the desired orifice cross-section.
  • the spinneret plate forms one electrode (usually the anode) in an electrolytic cell containing the appropriate electrolyte. With an applied direct current, the exposed metal is gradually removed as ions that enter the electrolyte solution. Poor dimensional control limits this method to large capillaries, or to other holes in which large dimensional variations can be tolerated.
  • Another method depends upon a tool piece having the exact cross-section desired in the orifice; a rod having three radial ribs, for example, constitutes the tool for Y-section orifices.
  • the spinneret blank is submerged in a liquid slurry of abrasive material, and the end of the shaped tool piece is brought into contact with the spinneret plate as the tool is vibrated at ultrasonic frequency.
  • High frequency impact of abrasive particles erodes the metal away as the tool is advanced into the resultant shaped crater until the hole passes completely through the plate.
  • the capillary converges in the direction of tool advance, one end of the capillary differing from the other by as much as 50-75 percent in cross-sectional area.
  • Another method of forming capillaries also depends upon a shaped tool piece having the cross section desired in the orifice.
  • the tool comprises one electrode and the spinneret plate the other electrode in an electrical circuit.
  • the spinneret blank mounted on an electrically insulated holder is submerged in a dielectric liquid.
  • One lead from a source of is connected to the spinneret plate and the other lead is connected to the shaped electrode tool.
  • the end of the tool is advanced against the spinneret plate until dielectric breakdown occurs with spark flash that melts out a microscopic crater. Such electroerosion occurs repeatedly until the tool erodes a hole completely through the plate.
  • the shape of the holes is similar to the shape of the electrode, but the capillary converges in the direction of electrode travel and wall finish is very rough unless the cutting rate is uneconomically low.
  • the spinneret capillary is quite unusable commercially.
  • the capillary dimensions and wall finish may be brought to an acceptable state. In common with several of the previously mentioned techniques, these multiple finishing operations make the method unduly expensive.
  • the active electrode is in the form of a metal wire held under tension by weights.
  • the electrode wire is threaded through a small pilot hole in the spinneret blank that is the anode of the circuit.
  • a film of dielectric fluid is spread on the spinneret surrounding the electrode, and the wrie is moved axially back and forth as it bears against the wall of the pilot hole.
  • Spark erosion gradually erodes away the metal of the spinneret at the contacting area to form a slot slightly wider than the diameter of the electrode wire.
  • the wire may be shifted in a direction normal to its axis, or the same relative motion may be obtained by moving the spinneret in the opposite direction, the wire being held at a fixed position.
  • the reciprocating wire is caused to traverse the path required to generate the desired slot or other opening.
  • this method provides the most versatile method ofmanufacturing noncircular capillaries since either straight or curved boundaries may be accurately formed. With care, dimensional accuracy and reproducibility may be maintained with negligible differences between the inlet and outlet ends of the capillary.
  • Major drawbacks of the method are a slow rate of cutting and a slightly rough, pebble-grain wall finish. High costs due to the slow production rate is in practice the principal factor limiting utility of this prior art method.
  • the present invention is an improvement in the basic wi e el ctro e m h of cutt ag c pi laries.
  • Another object of the present invention is to provide an improved apparatus for electroerosively machining a capillary in a spinneret to provide orifices therein having a non-circular cross-section.
  • Yet another object of the present invention is to provide a method of electroerosively cutting branches in a spinneret capillary.
  • apparatus for electroerosively machining a surface of a workpiece utilizes a source of direct current electrical energy.
  • An electrically conductive cutting wire is connected to the negative side of the electrical energy.
  • the connection is made to provide a parallel supply of electrical current to each of the ends of the wire. This parallel supply minimizes current flow variations due to changes in resistance set up as the wire engages in the electroerosion operation.
  • the apparatus includes means for reciprocating the wire in proximity to a workpiece having a surface to be machined.
  • the positive side of the electrical energy is connected to the workpiece.
  • a spark eroding discharge is set up between the workpiece and the wire as the latter reciprocates.
  • Means is used for discharging a free oxygencontaining gas at the point of spark discharge.
  • To provide for progression of the electroerosive machining means is included for moving the workpiece perpendicularly relative to the axis of the wire.
  • the apparatus can advantageously be used to machine a capillary in a spinneret plate.
  • a specific embodiment for doing this employs a pair of vertically aligned freely rotatable pulleys.
  • An electrically conductive wire is vertically reciprocatably arranged for engagement with and between the pulleys.
  • the spinneret plate has a small pilot hole through which the wire normally extends.
  • Means which may include a variable resistance connects the positive terminal of a direct current supply in electrical serial relationship to the spinneret plate.
  • a positively driven pulley having an eccentric juncture to which one end of the wire is mounted is used to impart the reciprocation of the wire.
  • Means which may include two springs mounted to a frame is used to connect the negative terminal of the direct current supply in electrical parallel relationship to opposite ends of the wire to provide a spark eroding discharge between the spinneret and the wire.
  • At least one small bore tube or the like is employed for discharging a free oxygen-containing gas at the place of spark erosion.
  • the provision of parallel current flow to ends of the wire can be made through the freely rotatable pulleys.
  • the method herein provides for cutting branches in a spinneret capillary. This is done by placing a small pilot hole in a spinneret and extending an electrically conductive wire through the hole. Each of the ends of the wire is connected in parallel to the negative side of a direct current electrical energy source. The spinneret is connected to the positive side of the energy source. The wire is reciprocated close to a portion of the inside surface of the pilot hole to provide a spark eroding discharge therebetween. A stream of gas containing at least about 14 percent by volume oxygen is established and directed to the point of spark erosion. The spinneret is moved relative to the axis of the wire to provide for progression of the spark erosion, thereby to cut a branch in the spinneret extending from the pilot hole.
  • FIGURE 1 shows schematically apparatus suitable for carrying out the method.
  • FIGURE 2 shows schematically certain desirable modifications in the apparatus illustrated in FIGURE 1.
  • FIGURE 3 illustrates another modification of the apparatus.
  • FIGURE 4 illustrates some shapes of various orifices that are readily made by the method of the invention.
  • FIGURE 5 is a graphical representation of certain data given in Table 1, which illustrates the effect of oxygen concentration in the local atmosphere upon the rate of removal of metal by the method of the invention.
  • FIGURE 6 is a graph illustrating the effect of local atmospheric gas flow rate upon the rate of metal removal according to the method of the invention.
  • FIGURE 7 is a graphical representation of data illustrating the effect of the axial speed of the wire electrode upon the rate of removal of metal by the method of the invention.
  • FIGURE 1 In FIGURE 1 are shown two freely rotatable electrically nonconductive pulleys 1 and 3; the shafts of the pulleys are supported by a frame (not shown). Passing over the two pulleys 1 and 3 is a fine wire 2 which forms one electrode (cathode) in an electrical circuit. One end of the wire is fastened at 4 to one end of a helically coiled spring 5 that is anchored to a frame at 6, and the other end of the wire is attached to a juncture or clamp 7 which pivots about a pin attached to drive wheel 8.
  • the drive wheel 8, pulleys 1 and 3, and anchor pin 6 are all electrically insulated from the frame; this requirement is most easily achieved by making each of these members of nonconductive plastic material such as nylon, polystyrene, polymethacrylate, etc.
  • Numeral 9 indicates a schematic cross-section of a metal spinneret blank having a conventional counterbore from the back side and a pilot hole through which wire electrode 2 passes.
  • the spinneret is fastened by clamps (not shown) to a conventional precision table 10 such as commonly used with micro drill presses or milling machines; by means 10a, such as micrometer screws and a rotational axis, table 10 may be shifted accurately in any direction and with it the spinneret.
  • a direct curernt source (DC) is provided and connected with polarities as indicated.
  • An ammeter A and a rheostat or potentiometer P are in series so that current flow in the circuit may be set at any desired level; a voltmeter may also be included.
  • the negative electrode or cathode of the current source is electrically connected to both ends of the wire electrode through spring 5 and the loosely coiled wire 11.
  • a short length of small-bore tubing 12, such as hypodermic tubing is held to the frame by an adjustable clamp such that the longitudinal axis of the tube is aimed at the intersection of the wire and the face of the spinncret.
  • Oxygen-containing gas under pressure supplied to the hypodermic tubing forms a high velocity jet that impinges directly on the wire at the region of contact between the wire and the spinneret blank.
  • FIGURE 1 The mechanical operation of the appaartus shown in FIGURE 1 can be seen from the drawing.
  • pivoted clamp 7 describes a circular path; and wire 2 is moved axially between the two pulleys a distance equivalent to the diameter of the circular path.
  • wire 2 For each complete revolution of the drive wheel the wire moves first in one direction and then an equal distance in the opposite direction, or a total travel of twice the diameter of the circle of rotation of pivot 7.
  • metal is eroded away.
  • a template 13 of electrically nonconducting material resting on the spinneret and in contact with the wire may be used to guide the path of the spinneret relative to the wire as it is moved by precision table 10 to generate the desired orifice shape.
  • the jet of gas from tube 12 assists mechanically by blowing eroded particles away from the active area. Precision movements and observations of the spinneret can be made with the aid of a conventional low power microscope having long working distance focused on the intersection of the wire and spinneret face.
  • the electrical circuit usually includes a blank of capacitors intended to provide a large surge current at sparking discharge.
  • the electrode was either submerged in or coated with a dielectric liquid which presumably served as a coolant and to assure complete charging of capacitors, while also excluding air from the erosion area.
  • both the capacitors and the dielectric liquid are eliminated from the circuit, resulting in a positive improvement in performance. Rate of metal removal is not sacrificed and dimensional variation in slot width is reduced.
  • the mil one onethousandth of an inch
  • cycle is meant one complete stroke of the wire, while stroke length is the distance through which the wire moves in one direction during a cycle.
  • the metal removal rate is expressed in terms of the volume of metal removed per unit of time, specifically the number of cubic mils of metal removed per minute.
  • volume percent oxygen cubic mils/ min. 30
  • the metal removal rate increases rapidly as the oxygen concentration in the local atmosphere increases.
  • the cutting rate becomes quite significantly increased at about 3540 percent oxygen concentration and higher.
  • Atmospheric air nominally contains 21 percent oxygen by volume, and rather than diluent such as nitrogen being used, air supplemented by 15-20 percent additional oxygen would be preferred if a moderate cutting rate increase were desired.
  • the local atmosphere at the active portion of the electrode should contain at least 35 percent (volume) of free oxygen and preferably 50-100 percent oxygen.
  • the rate of cutting by the method of the invention also depends upon the stroke length and speed of axial movement of the wire.
  • the stroke length might be less than the thickness of the metal being cut, while there appears to be no upper limit except as restricted by physical limitations. It has been found, however, that for practical use in spinneret production the stroke length should be no shorter than about one inch and preferably no longer than about 6 inches, the lower limit being the more important.
  • the speed of axial movement of the wire is of great importance and is, of course, dependent upon the stroke length such that a higher frequency of reciprocation is required to achieve a given speed as the stroke length is decreased. The significance of these factors is illustrated by the data shown graphically in FIGURE 7. These data were obtained by operating apparatus as shown in FIGURE 1 under these general conditions:
  • Wire electrode Tungsten, 4.8 mils dia.
  • Oxygen fiow rate 7 liters/ min.
  • Stroke lengths were varied from 0.1875 inch to 4.5 inches and frequency was varied from 50 to 800 cycles/min. in this series of tests. Stroke lengths are shown on the appropriate graphs in FIGURE 7. To bring the various data to a common basis, electrode speed is expressed as feet per minute of axial travel.
  • FIGURE 7 clearly illustrates, for a given stroke length a maximum cutting rate may be attained and further increase in electrode speed does not significantly increase the rate of removal of metal. It is also seen that a significant metal removal rate is not attained unless an electrode speed of about 40 feet/minute is reached. The actual positions of the curves plotted are shifted upward or downward in FIGURE 6 depending upon wire size and other factors but there is little shift along the axis of electrode speed. In the particular examples shown in FIGURE 7 it is noted that the maximum rate of removal of metal is achieved with a stroke length of 3.5 inches and electrode speed of about feet/minute. According to the method of the invention a stroke length in the range of 1 to 6 inches, preferably 2-5 inches, is to be used with an axial wire speed of at least 40 feet/minute and preferably in the range of 50 to 250 feet/minute.
  • the presence of supplemental free oxygen in the local atmosphere surrounding the active electrode wire not only increases the rate of metal removal but, surprisingly, improves dimensional accuracy and wall finish of the capillary.
  • the actual slot width cut by a wire of given diameter depends significantly upon the current flow in the circuit.
  • a tungsten wire electrode of 2.8 mils diameter was used under similar conditions except that oxygen was blown on the electrode in one case and air in the other, while cutting Type 430 S/S stock 20 mils thick:
  • slot width mils Current, ma. Air Oxygen Metal removal rate also increases with current, but note that slot width is constant over an appreciable range of current flow when oxygen is used instead of air. The difference is even more pronounced when a wire composed of Perma-Nickel is used; with air and 600 ma. current, the slot width is about 3.7 mils. A similar situation occurs with wires of other sizes; a tungsten wire 4.8 mils in diameter characteristically cuts a slot 5 .0' mils wide when used with oxygen. By proper choice of wire diameter, slot width can be chosen within very close limits and be reproduced repeatedly.
  • the wall finish of the capillary becomes progressively rougher as the metal removal rate is increased either by increasing the current or by increasing the electrode speed. It was therefore the more surprising to find capillary wall finish greatly improved when metal removal rate was increased by the presence of supplemental free oxygen.
  • the resultant wall is so smooth that no further treatment is necessary prior to putting the spinneret into service.
  • the improved uniformity of polymer flow in melt spinning is directly observable at the spinneret and is confirmed by the reduced interfilarnent denier variation in the spun yarn.
  • the improved capillary wall finish may be rationalized by consideration of at least two factors. Electroerosion as normally performed under a dielectric liquid or in the presence of a predominantly inert gas probably involves removal of particles of free metal; these particles are actually torn from the metal mass by the action of the electric spark and the moving electrode drags these relatively hard particles across the surface of the bulk metal so that the net result is a relatively pitted or pebbly Wall finish. On the other hand, with free oxygen available at the spark spite, it is probable that the metal surface oxidizes rapidly and only the softer friable metallic oxides, rather than metal particles, are eroded away.
  • FIGURE 4 illustrates a number of cross sections of spinneret orifices that are readily made by the method of the invention.
  • the dotted circle represents the position at which the pilot hole may be located for the initial stringup of the wire electrode through the spinneret blank. Curved boundaries of any arbitrary shape, as well as straight boundaries, are practicable. In general, one pilot hole must be drilled for any group of interconnected slots.
  • a guide template of nonconductive material such as ceramic or, preferably, synthetic sapphire (alumina) may be used to assist the operative controlling movement of the spinneret relative to the electrode.
  • a straight guide would be placed on top of the spinneret blank as indicated by numeral 13 in FIGURE 1; the operator then moves the spinneret periodically so that the electrode wire moves parallel to and lightly touching against the straight edge of the guide; the position of the guide is shifted to a new position as each of the three straight slots comprising the orifice are completed.
  • a curved guide is used in like manner to make a curved boundary such as illustrated in FIGURE 4-1.
  • a new phenomenon of practical significance is observed in the action of the wire electrode used according to the invention.
  • the wire acts as if it were attracted by the actively eroding area of the spinneret blank; that is, the wire appears to be drawn into the spark site by some force acting normal to the axis of the wire.
  • the practical importance of this effect is that the wire now has a natural" tendency to follow the guided path once electroerosion is initiated.
  • With direct guide templates the wire tends to maintain snug contact with the guide edge, and with spinnerets guided by remote linkage the wire follows very accurately the imposed changes in direction without the tendency to drift off course that occurs when air alone is used.
  • This stabilization of the active electrode by the attraction phenomenon is also believed to be a contributing factor in the improved dimensional control achieved by the method of the invention.
  • the two pulleys 1 and 3 are now made of electrically conducting material, preferably aluminum or silver-plated copper; pulley bearings are insulated from the frame and each pulley is connected to the negative pole of the DC source by means of spring brushes 19 and 20 bearing directly against the pulleys, or by other common expedients for making electrical connection with rotating members. Current flows through the wire to the pulleys so that the effective length of wire in the electrical circuit is constant at all parts of the cycle. Oxygen is brought to the spark area by means of a tube 14 having a T branch to admit metered stream of oxygen.
  • a small O-ring 16 seals the tube 14 to the bottom surface of the spinneret.
  • Wire electrode 2 passes through a small nonconductive abrasion resistant eyelet 15 that has a hole just large enough to freely pass the wire.
  • Some oxygen delivered to tube 14 escapes at eyelet 15 but the much greater fraction is forced to pass through the capillary being cut by the wire electrode, assuring an oxygensaturated atmosphere and high efficiency.
  • a slight drop in metal removal rate occurs, presumably due to more oxygen flowing through the open area adjacent the electrode.
  • FIGURE 3 illustrates schematically an alternate arrangement for improving oxygen utilization efficiency that in practice is slightly superior to the method illustrated in FIGURE 2 but does require more care and patience of the operator.
  • a second hypodermic tube 21 delivering a metered stream of oxygen is mounted under the precision table 10 to direct a jet of oxygen upward into the counterbore of the capillary being cut by the electrode 2.
  • the two oxygen streams to hyperdermic tubes 12 and 21 are metered independently, tube 21 generally requiring only about one-half as much oxygen as tube 12 for efficient operation.
  • both ends of the electrode wire are connected to the negative terminal of the DC. power source.
  • This parallel path for current flow eliminates the gross current and voltage fluctuations revealed by ordinary damped ammeters and voltmeters when only one end of the wire is connected. Uniformity of cutting is improved, and a small but significant increase in cutting rate is also gained as illustrated by these data:
  • Wire electrode Tungsten, 2.4 mils dia. (slot width 2.6
  • Electrode speed 80.2 feet/minute (3.25 inch stroke).
  • Oxygen rate liters/ minute.
  • Electrode condition cubic mils/ min.
  • the actual metal removal rate depends upon many controllable factors such as current, electrode speed, oxygen flow rate and concentration, etc. The rate, of course, also depends upon the type of material being cut; aluminum or Incoloy, for example, practically are not eroded by the method of the invention.
  • the base metals utilized almost universally for meltspinning spinnerets, namely, stainless steel alloys, are readily cut by the method of the invention.
  • Stainless steels Type 316 and Type 430 are most commonly used for spinnerets. Other more uncommon materials, such as titanium, are also easily out according to the method of the invention.
  • a tungsten wire electrode 4.8 mils diameter with 600 ma. current and 7 liters/minute of oxygen flow was used to obtain the data in Table III presented to illustrate differences in the cutting rates of different materials.
  • Type 316 S/ S is cut much more rapidly than Type 430 8/8, and that all three of the materials are removed at much greater rate than even 316 S/ S when it is electroeroded in the absence of supplementary oxygen.
  • any of the common direct current sources may be used in the circuit according to the invention, such as a primary chemical cell, a direct current generator, or an alternating current source with rectifier.
  • the actual voltage required depends upon the length of wire and physical size chosen for the electroerosion machine.
  • the electrode guide pulleys 1 and 3 of FIGURE 1 were spaced several feet apart vertically. It now has been found that to 20 inches spacing is entirely adequate for normal spinneret and extrusion die manufacture. With such dimensions very compact but highly versatile machines are practicable, and a range of voltage from 5 to 25 is entirely adequate.
  • An impressed of 9-15 volts is normally sufiicient to provide a reasonably optimum maximum current of 600 ma. Occasionally it is desirable to be able to raise the current to a higher level to compensate some particular factor such as very long capillaries, but current much in excess of one ampere may be accompanied by a rougher wall finish that is undesirable.
  • the general eifect of current on the cutting rate may be seen in these data obtained with Type 430 S/ S cut with a tungsten wire electrode 4.8 mils diameter, and with 7 liters/minute oxygen fiow.
  • the DC. source was a common battery eliminator rectifier with slightly pulsating output D.C.:
  • the method of the invention is applicable to cutting surfaces of various workpieces but finds its greatest advantage when slots are not wider than about 25 mils and a high order of accuracy is required.
  • Apparatus for machining a capillary in a spinneret plate comprising:
  • Apparatus for machining a capillary in a spinneret plate comprising:
  • (h) means for connecting the negative terminal in electrical parallel relationship through each of the freely rotatable pulleys to the wire to provide a spark eroding discharge between the spinneret and the wire as the latter reciprocates;
  • (j) means for moving the spinneret relative to the axis of the wire to provide for progression of the spark erosion.
  • Apparatus for electroerosive machining comprising:
  • the apparatus of claim 5 including means for discharging an electroerosion supporting fluid at the point of spark discharge.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Electrical Discharge Machining, Electrochemical Machining, And Combined Machining (AREA)
US553369A 1966-05-27 1966-05-27 Electroerosive machining Expired - Lifetime US3493710A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US55336966A 1966-05-27 1966-05-27

Publications (1)

Publication Number Publication Date
US3493710A true US3493710A (en) 1970-02-03

Family

ID=24209150

Family Applications (1)

Application Number Title Priority Date Filing Date
US553369A Expired - Lifetime US3493710A (en) 1966-05-27 1966-05-27 Electroerosive machining

Country Status (9)

Country Link
US (1) US3493710A (de)
AT (1) AT265459B (de)
BE (1) BE699141A (de)
CH (1) CH520541A (de)
DE (1) DE1690601A1 (de)
GB (1) GB1159757A (de)
IL (1) IL28038A (de)
LU (1) LU53761A1 (de)
NL (2) NL6707389A (de)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2721804A1 (de) * 1976-05-14 1977-12-01 Inoue Japax Res Verfahren und vorrichtung zur elektroerosiven bearbeitung
US4333806A (en) * 1979-08-30 1982-06-08 Inoue-Japax Research Incorporated Method of and apparatus for electroerosively machining a contour in a workpiece with a traveling-wire electrode
US4527035A (en) * 1981-07-30 1985-07-02 Corning Glass Works Wire electrical discharge machine flushing process and apparatus
US4698476A (en) * 1982-05-06 1987-10-06 Mitsubishi Denki Kabushiki Kaisha Automatic wire feeder for an electrical discharge machining apparatus including combined cleaning fluid and working fluid supply systems
CN103084680A (zh) * 2013-02-07 2013-05-08 哈尔滨理工大学 采用多介质改善电火花线切割加工质量的方法
CN105840062A (zh) * 2016-05-12 2016-08-10 成都点石创想科技有限公司 一种紧急情况下具有自毁功能的门

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH560574A5 (de) * 1973-09-11 1975-04-15 Agie Ag Ind Elektronik
DE2705217C3 (de) * 1976-03-01 1981-08-27 Matsushita Electric Industrial Co., Ltd., 1006 Kadoma, Osaka Vorrichtung zur Beseitigung der Unwucht eines um eine Drehachse umlaufenden Rotors
CH640161A5 (de) * 1978-04-18 1983-12-30 Agie Ag Ind Elektronik Verfahren und einrichtung zur spuelung der bearbeitungszone beim funkenerosiven schneiden.

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US76191A (en) * 1868-03-31 Hermann d
US1839647A (en) * 1931-02-07 1932-01-05 Reginald B Smith Jig saw
US2059236A (en) * 1932-08-13 1936-11-03 Electric Arc Cutting & Welding Method of machining by electric current
US2906853A (en) * 1957-12-06 1959-09-29 Air Reduction Electric arc cutting
US2934631A (en) * 1955-06-30 1960-04-26 Imalis Rose Electrolytic metal shaping
US3087043A (en) * 1960-06-23 1963-04-23 Engelhard Ind Inc Method of making spinnerettes
US3366771A (en) * 1963-08-26 1968-01-30 Int Standard Electric Corp Spark-erosion machining

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US76191A (en) * 1868-03-31 Hermann d
US1839647A (en) * 1931-02-07 1932-01-05 Reginald B Smith Jig saw
US2059236A (en) * 1932-08-13 1936-11-03 Electric Arc Cutting & Welding Method of machining by electric current
US2934631A (en) * 1955-06-30 1960-04-26 Imalis Rose Electrolytic metal shaping
US2906853A (en) * 1957-12-06 1959-09-29 Air Reduction Electric arc cutting
US3087043A (en) * 1960-06-23 1963-04-23 Engelhard Ind Inc Method of making spinnerettes
US3366771A (en) * 1963-08-26 1968-01-30 Int Standard Electric Corp Spark-erosion machining

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2721804A1 (de) * 1976-05-14 1977-12-01 Inoue Japax Res Verfahren und vorrichtung zur elektroerosiven bearbeitung
US4333806A (en) * 1979-08-30 1982-06-08 Inoue-Japax Research Incorporated Method of and apparatus for electroerosively machining a contour in a workpiece with a traveling-wire electrode
US4527035A (en) * 1981-07-30 1985-07-02 Corning Glass Works Wire electrical discharge machine flushing process and apparatus
US4698476A (en) * 1982-05-06 1987-10-06 Mitsubishi Denki Kabushiki Kaisha Automatic wire feeder for an electrical discharge machining apparatus including combined cleaning fluid and working fluid supply systems
CN103084680A (zh) * 2013-02-07 2013-05-08 哈尔滨理工大学 采用多介质改善电火花线切割加工质量的方法
CN103084680B (zh) * 2013-02-07 2017-02-08 哈尔滨理工大学 采用多介质改善电火花线切割加工质量的方法
CN105840062A (zh) * 2016-05-12 2016-08-10 成都点石创想科技有限公司 一种紧急情况下具有自毁功能的门
CN105840062B (zh) * 2016-05-12 2020-05-01 成都点石创想科技有限公司 一种紧急情况下具有自毁功能的门

Also Published As

Publication number Publication date
AT265459B (de) 1968-10-10
GB1159757A (en) 1969-07-30
NL7308891A (de) 1973-09-25
DE1690601A1 (de) 1972-03-16
CH520541A (fr) 1972-03-31
NL6707389A (de) 1967-11-28
BE699141A (de) 1967-11-29
LU53761A1 (de) 1967-09-08
IL28038A (en) 1971-01-28

Similar Documents

Publication Publication Date Title
Sabahi et al. Investigating the effect of mixed alkaline electrolyte (NaOH+ KOH) on the improvement of machining efficiency in 2D electrochemical discharge machining (ECDM)
EP0366466B1 (de) Kombiniertes Bohren mittels Elektroentladungsbearbeitung und Ultraschall
Hung et al. Using a helical micro-tool in micro-EDM combined with ultrasonic vibration for micro-hole machining
US4159407A (en) Methods and apparatus for electrically machining a work piece
US3493710A (en) Electroerosive machining
Jahan Micro-electrical discharge machining
US4113587A (en) Method for electrochemical machining
US4605834A (en) Precision TW electroerosion with staggering multiple V-notched guides
Li et al. Impulse discharge method to investigate the influence of gap width on discharge characteristics in micro-EDM
Rudorff Principles and applications of spark machining
CN104625267A (zh) 一种线锯绕制电极电解-机械微细切割加工方法
US3487189A (en) Electro-erosive machining
US3509304A (en) Electroerosive machining of spinneret capillaries using alternating current
US3928154A (en) Electrochemical radius generation
Liu et al. Electric discharge milling of polycrystalline diamond
EP0130758A1 (de) Genaues elektroerosives Bearbeiten mit Durchlaufelektrodendraht und mehreren übereinanderliegenden Führungsöffnungen
CN111151831B (zh) 双极性电解放电加工工件的方法及实施装置
CN104625266A (zh) 一种线锯绕制电极电解-机械微细切割加工系统
Wu et al. Experiment investigation of using wire electrochemical machining in deionized water to reduce the wire electrical discharge machining surface roughness
Mukhopadhyay et al. Advancement in ultrasonic vibration and magnetic field assisted micro-EDM process: an overview
Dutta et al. Hybrid electric discharge machining processes for hard materials: a review
GB2077171A (en) Electroerosive wire-cutting method and apparatus
Saini et al. Electrochemical discharge machining process, variants and hybridization: A review
US4001538A (en) Method and apparatus for producing smooth surfaces
Paul et al. Improvement in micro feature generation in ECDM process with powder mixed electrolyte