CA1068791A - Spark erosion by two parallel spaced wire electrodes - Google Patents
Spark erosion by two parallel spaced wire electrodesInfo
- Publication number
- CA1068791A CA1068791A CA260,567A CA260567A CA1068791A CA 1068791 A CA1068791 A CA 1068791A CA 260567 A CA260567 A CA 260567A CA 1068791 A CA1068791 A CA 1068791A
- Authority
- CA
- Canada
- Prior art keywords
- wires
- spark
- electrodes
- edges
- spaced
- 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
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B26—HAND CUTTING TOOLS; CUTTING; SEVERING
- B26F—PERFORATING; PUNCHING; CUTTING-OUT; STAMPING-OUT; SEVERING BY MEANS OTHER THAN CUTTING
- B26F1/00—Perforating; Punching; Cutting-out; Stamping-out; Apparatus therefor
- B26F1/26—Perforating by non-mechanical means, e.g. by fluid jet
- B26F1/28—Perforating by non-mechanical means, e.g. by fluid jet by electrical discharges
-
- 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
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- Forests & Forestry (AREA)
- Electrical Discharge Machining, Electrochemical Machining, And Combined Machining (AREA)
- Perforating, Stamping-Out Or Severing By Means Other Than Cutting (AREA)
- Processing Of Stones Or Stones Resemblance Materials (AREA)
- Crystals, And After-Treatments Of Crystals (AREA)
- Arc Welding In General (AREA)
Abstract
ABSTRACT OF DISCLOSURE
A method of cutting a material, which may be insulating or conducting, which includes the steps of placing a pair of parallel spaced electrodes, preferably taking the form of a pair of wires, close to or in contact with the material, applying a voltage across the electrodes and causing relative movement between the electrodes and the material as the spark erodes the material to effect the cut. The invention also provides apparatus for carrying out this method.
A method of cutting a material, which may be insulating or conducting, which includes the steps of placing a pair of parallel spaced electrodes, preferably taking the form of a pair of wires, close to or in contact with the material, applying a voltage across the electrodes and causing relative movement between the electrodes and the material as the spark erodes the material to effect the cut. The invention also provides apparatus for carrying out this method.
Description
~06879~
THIS invention relates to the cutting of materials using spark erosion techniques.
In prior art spark erosion cutting of conducting materials, one or more cutting elements, all at a high positive or negative voltage with respect to the material being machined (which is sometimes earthed) are used such t.~at sparks are generated between the cutting elements and the material. The spark causes degradation of the material, which erodes in a controlled manner, thus resulting in the desired cutting.
However, the above method of cutting cannot be used for insulating materials without first providing a conductive path between the region of the cut and the external circuit. In the case of diamond, it is necessary first to carbonize the surface of the diamond, so that a con-ducting path between the cutting element at high voltage and earth is present. Sparking between the cutting element and the diamond can then take place since it has been found that, on spark erosion, a layer of carbon is formed over the spark eroded regions, thus maintaining the conducting path. In the case of those insulators, for which no such conducting layer is formed during spark erosion or provided by other means, the prior art tech-niques will not cut the insulating material.
According to the invention, a method of cutting a material utilizing a pair of spaced electrodes presenting parallel,elongate and spaced edges includes the steps of placing the edges close to or in contact with the material, applying a voltage across the electrodes to produce a spark between the edges, and causing re-lative movement between the electrode edges and material as the spark erodes the material to effect the cut. Preferably the
THIS invention relates to the cutting of materials using spark erosion techniques.
In prior art spark erosion cutting of conducting materials, one or more cutting elements, all at a high positive or negative voltage with respect to the material being machined (which is sometimes earthed) are used such t.~at sparks are generated between the cutting elements and the material. The spark causes degradation of the material, which erodes in a controlled manner, thus resulting in the desired cutting.
However, the above method of cutting cannot be used for insulating materials without first providing a conductive path between the region of the cut and the external circuit. In the case of diamond, it is necessary first to carbonize the surface of the diamond, so that a con-ducting path between the cutting element at high voltage and earth is present. Sparking between the cutting element and the diamond can then take place since it has been found that, on spark erosion, a layer of carbon is formed over the spark eroded regions, thus maintaining the conducting path. In the case of those insulators, for which no such conducting layer is formed during spark erosion or provided by other means, the prior art tech-niques will not cut the insulating material.
According to the invention, a method of cutting a material utilizing a pair of spaced electrodes presenting parallel,elongate and spaced edges includes the steps of placing the edges close to or in contact with the material, applying a voltage across the electrodes to produce a spark between the edges, and causing re-lative movement between the electrode edges and material as the spark erodes the material to effect the cut. Preferably the
- 2 -.~i.'. ~
~068791 erosion takes place in a 5Ui table dielectric medium. To effect cutting movemènt of the electrodes through the material in the direction of cut must take place as the material is eroded~ This movement may be achieved by moving the electrodes or the material or both.
The electrodes may be provided by the edges of a pair of parallel plates, which edges are preferably sharpened.
Sharpened edges have the advantage that the spark will preferentially be produced at these edges. The plates may be of any suitable configuration. For example, the plates may be rectangular or they may be cylindrical, the one cylinder being inside the other.
In a preferred form of the invention, the electrodes are provided by a pair of parallel wires. The wires may lie in the same plane as the direction of relative movement of electrodes and material during cutting. Alternatively, the wires may lie in a plane which is perpendicular or at any other angle to this direction of movement.
The cross-sectional dimensions of the electrodes and the gap between the electrodes will vary according to the nature of the material being cut and the size of cut desired. For example, in the case of small objects such as diamonds the electrodes will be thin and the gap between them will be small. However, in the case of massive objects such as a block of metal or concrete, narrow cuts will generally not be required with a result that both the electrodes could be thick and the gap between the electrodes could be relatively large. Clearly the gap ~0 should not be so large that sparking is inhibited.
106879~
The voltage which is applied across the electrodes musc be such as to produce a spark. The voltage applied will generally be between 500 and 20,000 volts. The rate of erosion and hence the cutting speed is dependent on the power dissipated by the spark. The power can be varied by adjusting the energy of the voltage pulse and the frequency of the pulse. However faster degradation leads to poorer surface finish. The parameters may be selected to ach;eve a desired surface finish.
C) As is mentioned above, the spark which is generated between the electrodes causes erosion for degradation of the material. As the material is removed, the electrodes and the workpiece are moved closer to each other, as discussed above, and the desired cut is produced. The electrodes may be moved through the material in the direction of cut by applying a load to the electrodes.
The load forces the electrodes through the material as erosion takes place. The load which will be applied to the electrodes will vary according to parameters such as frictional force and mechanical tensioning of the electrodes.
By way of example, it has been found that for wires and diamond, a load of between 1 and 50 grams applied to the wires produces a satisfactory cut. Alternatively,the electrodes may be kept sationary and the workpiece moved across the stationary electrodes by use of a suitable servo-mechanism as described fully in Electro-Erosion Machining of Metals by Livshits A.L., Butterworths, London 1960.
The method of the invention has particular application to the cutting of insulating materials due to the fact that it is not necessary by this method to form a conducting layer on the material. Examples of insulating materials ~068791 which can be cut by the method of the invention are d;amond, cubic boron nitride and ceramics such as aluminium oxide, spinel and porcelain. The invention also finds application with conducting materials such as tungsten carbide, cemented tungsten carbide, steels and other metals, diamond and cubic boron nitride compacts and semi-conductors such as silicon and germanium.
During cutting the workpiece is electrically floating and assumes a potential which depends on the particular -~ 10 operating conditions.
The spark erosion of the material may take place in a suitable dielectric liquid which serves to confine the spark to the cutting zone while at the same time acting as a coolant and a flushing agent for clearing particles detached from electrodes and the workpiece. Suitable dielectrics are liquids such as petroleum, kerosene, tetrachloromethane, trichloroethylene, tetraline, olive oil and paraffin oil. Generally these are liquids with high flash point which are non-conducting until the field breakdown strength is exceeded and which then deionize rapidly. A stream of the liquid can be poured over the zone in which sparking takes place.
Alternatively, this zone may be immersed in a bath of the liquid.
In one particular example of the invention, the method utilises a pair of spaced parallel wires to cut diamond.
The shape of the wires is not critical although for con-venience the wires will generally have a circular cross-section. The wire thickness will in general be in the range 0,01 mm to 0,1 mm and the gap between the wires will generally not exceed 2 mm. The gap preferably lies 1068'~91 in the range 0,025 to 2mm.
According to another aspec-t of the invention, there is provided apparatus for cutting a material including a pair of spaced electrodes presenting parallel, elgonate and spaced edges adapted to be placed close to or in contact with the material, means to apply a voltage across the electrodes to produce a spark in a zone between the edges, and means to move the electrode edges and the material relatively to each other as the spark erodes the material to effect the cut.
Each electrode preferably comprises a wire. Where the electrodes are provided by wires it is preferable t~ pro-vide a feed roller and a take-up roller for the wires;
the rollers being adapted continuously to feed wire through the spark zone. Furthermore, the apparatus may include means to vary the spacing between the wires in the spark zone. These means may comprise two spaced prongs, each prong straddling the wires and being rotatable about an axis which is transverse to the plane of the wires.
Figure 1 of the attached drawings illustrates diagram-matically a perspective view of an embodiment of apparatus for carrying out the method of the invention.
Figure 2 is a circuit diagram suitable for generating the sparking voltage.
Referring to the drawing, the apparatus comprises a pair of wires 10, 12 which are insulated from each other. Each wire runs from a tensioned feed roller 14 to a take up roller 16 and passes over two guides 18 and 20 and around capstands 21, 23. The capstan 23 which is closer to the take up roller is a drive capstan while the capstan 21 is merely a guide. The capstans 23 and the take up rollers 16 are arranged to rotate so that the wires move past each other in opposite directions. This ensures hat the wires are not fused to each other when a voltage is applied across them. The respective rolle~, guides and capstans of each wire are insulated from each other.
A diamond workpiece 22 is mounted on a pedestal 24 which is adapted to be moved up and down as indicated by the arrows. The pedestal may be adapted to be moved in this manner by being connected to a standard servo-mechanism as described for example in the Livshits reference mentioned above, The servo-mechanism main-tains a suitable constant distance between each wire and the workpiece and in this way movement of the wires through the workpiece, and hence cutting is effected as erosion takes place.
The w;res pass through prongs 26. The gap between the wires can be varied by varying the angle of the prongs to the wires, i.e. the prongs are rotatable about an axis transverse to the plane of the wires. In this manner the gap between the wires in the zone 27 between the prongs can be made narrower than the gap outside of the prongs to restrict the sparking to the zone 27.
A suitable voltage is applied across the wires by applying a voltage across one of the sets of guides. A circuit suitable for generating the sparking voltage is illustrated in Figure 2. The wires 10 and 12 are connected in series with an adjustable air gap 30. The width of the gap may be adjusted from ,25 mm to 3,5 mm. A capacitor 31 of capacity of the order of nanofarads is connected in parallel to the air gap 30 and the wires. A limiting resistance 32 of about 50,000 ohms is connected in series with the capacitor 31 and the circuit is supplied with power by means of a suitable variable high voltage d.c.
source connected to terminals 33. The voltage is adjustable from about 500 to 20,000 volts.
In use, the take-up rollers and capstans are rotated so that the wire from each feed roller passes between the two sets of guides and on to its take-up rol~er. The prongs 5 !are set at an angle to the wires so that the gap between the wires in the zone 27 between the prongs is narrower than the gap between the wires outside of this zone. A
, spark-producing voltage is applied across one of the sets C of guides, the voltage being selected such that the 10 spark is generated between the wires in the zone 27. The wires during sparking erode and could break. To prevent this the wires are not kept stationary and use is made of the continuous feed system described above. The wires ~re wound around the drive capstans 23 in their passage between the 15 two sets of guides to ensure that the wires move at a uniform speed through the sparking zone.
The diamond workpiece is moved to a position close to the wires in the sparking zone so that the spark erodes the diamand. A continuous flow of dielectric liquid is 20 poured over the sparking and eroding zone through pipe 28.
As erosion takes place, so the diamond moves upwards. In this manner the wires pass through the diamond and the diamond is cut.
An example of the invention in which a load was applied 25 to the wires (as opposed to the use of a servo-mechanism described above) will now be described. Two parallel wires, 0,05 mm in thickness, were separated by 0,25 mm.
The wires were placed close to a diamond workpiece and the diamond and the wires were immersed in a dielectric 30 liquid paraffin. A potential of approximately 4000 volts was applied across the two wires. A force of 10 ~C368791 grams in the direction of the cut was applied to the wires, and the resulting cuttillg rate of the wires through the diamond was approximately 1 mm3 /hour. The resulting cut was a very clean one.
O
~068791 erosion takes place in a 5Ui table dielectric medium. To effect cutting movemènt of the electrodes through the material in the direction of cut must take place as the material is eroded~ This movement may be achieved by moving the electrodes or the material or both.
The electrodes may be provided by the edges of a pair of parallel plates, which edges are preferably sharpened.
Sharpened edges have the advantage that the spark will preferentially be produced at these edges. The plates may be of any suitable configuration. For example, the plates may be rectangular or they may be cylindrical, the one cylinder being inside the other.
In a preferred form of the invention, the electrodes are provided by a pair of parallel wires. The wires may lie in the same plane as the direction of relative movement of electrodes and material during cutting. Alternatively, the wires may lie in a plane which is perpendicular or at any other angle to this direction of movement.
The cross-sectional dimensions of the electrodes and the gap between the electrodes will vary according to the nature of the material being cut and the size of cut desired. For example, in the case of small objects such as diamonds the electrodes will be thin and the gap between them will be small. However, in the case of massive objects such as a block of metal or concrete, narrow cuts will generally not be required with a result that both the electrodes could be thick and the gap between the electrodes could be relatively large. Clearly the gap ~0 should not be so large that sparking is inhibited.
106879~
The voltage which is applied across the electrodes musc be such as to produce a spark. The voltage applied will generally be between 500 and 20,000 volts. The rate of erosion and hence the cutting speed is dependent on the power dissipated by the spark. The power can be varied by adjusting the energy of the voltage pulse and the frequency of the pulse. However faster degradation leads to poorer surface finish. The parameters may be selected to ach;eve a desired surface finish.
C) As is mentioned above, the spark which is generated between the electrodes causes erosion for degradation of the material. As the material is removed, the electrodes and the workpiece are moved closer to each other, as discussed above, and the desired cut is produced. The electrodes may be moved through the material in the direction of cut by applying a load to the electrodes.
The load forces the electrodes through the material as erosion takes place. The load which will be applied to the electrodes will vary according to parameters such as frictional force and mechanical tensioning of the electrodes.
By way of example, it has been found that for wires and diamond, a load of between 1 and 50 grams applied to the wires produces a satisfactory cut. Alternatively,the electrodes may be kept sationary and the workpiece moved across the stationary electrodes by use of a suitable servo-mechanism as described fully in Electro-Erosion Machining of Metals by Livshits A.L., Butterworths, London 1960.
The method of the invention has particular application to the cutting of insulating materials due to the fact that it is not necessary by this method to form a conducting layer on the material. Examples of insulating materials ~068791 which can be cut by the method of the invention are d;amond, cubic boron nitride and ceramics such as aluminium oxide, spinel and porcelain. The invention also finds application with conducting materials such as tungsten carbide, cemented tungsten carbide, steels and other metals, diamond and cubic boron nitride compacts and semi-conductors such as silicon and germanium.
During cutting the workpiece is electrically floating and assumes a potential which depends on the particular -~ 10 operating conditions.
The spark erosion of the material may take place in a suitable dielectric liquid which serves to confine the spark to the cutting zone while at the same time acting as a coolant and a flushing agent for clearing particles detached from electrodes and the workpiece. Suitable dielectrics are liquids such as petroleum, kerosene, tetrachloromethane, trichloroethylene, tetraline, olive oil and paraffin oil. Generally these are liquids with high flash point which are non-conducting until the field breakdown strength is exceeded and which then deionize rapidly. A stream of the liquid can be poured over the zone in which sparking takes place.
Alternatively, this zone may be immersed in a bath of the liquid.
In one particular example of the invention, the method utilises a pair of spaced parallel wires to cut diamond.
The shape of the wires is not critical although for con-venience the wires will generally have a circular cross-section. The wire thickness will in general be in the range 0,01 mm to 0,1 mm and the gap between the wires will generally not exceed 2 mm. The gap preferably lies 1068'~91 in the range 0,025 to 2mm.
According to another aspec-t of the invention, there is provided apparatus for cutting a material including a pair of spaced electrodes presenting parallel, elgonate and spaced edges adapted to be placed close to or in contact with the material, means to apply a voltage across the electrodes to produce a spark in a zone between the edges, and means to move the electrode edges and the material relatively to each other as the spark erodes the material to effect the cut.
Each electrode preferably comprises a wire. Where the electrodes are provided by wires it is preferable t~ pro-vide a feed roller and a take-up roller for the wires;
the rollers being adapted continuously to feed wire through the spark zone. Furthermore, the apparatus may include means to vary the spacing between the wires in the spark zone. These means may comprise two spaced prongs, each prong straddling the wires and being rotatable about an axis which is transverse to the plane of the wires.
Figure 1 of the attached drawings illustrates diagram-matically a perspective view of an embodiment of apparatus for carrying out the method of the invention.
Figure 2 is a circuit diagram suitable for generating the sparking voltage.
Referring to the drawing, the apparatus comprises a pair of wires 10, 12 which are insulated from each other. Each wire runs from a tensioned feed roller 14 to a take up roller 16 and passes over two guides 18 and 20 and around capstands 21, 23. The capstan 23 which is closer to the take up roller is a drive capstan while the capstan 21 is merely a guide. The capstans 23 and the take up rollers 16 are arranged to rotate so that the wires move past each other in opposite directions. This ensures hat the wires are not fused to each other when a voltage is applied across them. The respective rolle~, guides and capstans of each wire are insulated from each other.
A diamond workpiece 22 is mounted on a pedestal 24 which is adapted to be moved up and down as indicated by the arrows. The pedestal may be adapted to be moved in this manner by being connected to a standard servo-mechanism as described for example in the Livshits reference mentioned above, The servo-mechanism main-tains a suitable constant distance between each wire and the workpiece and in this way movement of the wires through the workpiece, and hence cutting is effected as erosion takes place.
The w;res pass through prongs 26. The gap between the wires can be varied by varying the angle of the prongs to the wires, i.e. the prongs are rotatable about an axis transverse to the plane of the wires. In this manner the gap between the wires in the zone 27 between the prongs can be made narrower than the gap outside of the prongs to restrict the sparking to the zone 27.
A suitable voltage is applied across the wires by applying a voltage across one of the sets of guides. A circuit suitable for generating the sparking voltage is illustrated in Figure 2. The wires 10 and 12 are connected in series with an adjustable air gap 30. The width of the gap may be adjusted from ,25 mm to 3,5 mm. A capacitor 31 of capacity of the order of nanofarads is connected in parallel to the air gap 30 and the wires. A limiting resistance 32 of about 50,000 ohms is connected in series with the capacitor 31 and the circuit is supplied with power by means of a suitable variable high voltage d.c.
source connected to terminals 33. The voltage is adjustable from about 500 to 20,000 volts.
In use, the take-up rollers and capstans are rotated so that the wire from each feed roller passes between the two sets of guides and on to its take-up rol~er. The prongs 5 !are set at an angle to the wires so that the gap between the wires in the zone 27 between the prongs is narrower than the gap between the wires outside of this zone. A
, spark-producing voltage is applied across one of the sets C of guides, the voltage being selected such that the 10 spark is generated between the wires in the zone 27. The wires during sparking erode and could break. To prevent this the wires are not kept stationary and use is made of the continuous feed system described above. The wires ~re wound around the drive capstans 23 in their passage between the 15 two sets of guides to ensure that the wires move at a uniform speed through the sparking zone.
The diamond workpiece is moved to a position close to the wires in the sparking zone so that the spark erodes the diamand. A continuous flow of dielectric liquid is 20 poured over the sparking and eroding zone through pipe 28.
As erosion takes place, so the diamond moves upwards. In this manner the wires pass through the diamond and the diamond is cut.
An example of the invention in which a load was applied 25 to the wires (as opposed to the use of a servo-mechanism described above) will now be described. Two parallel wires, 0,05 mm in thickness, were separated by 0,25 mm.
The wires were placed close to a diamond workpiece and the diamond and the wires were immersed in a dielectric 30 liquid paraffin. A potential of approximately 4000 volts was applied across the two wires. A force of 10 ~C368791 grams in the direction of the cut was applied to the wires, and the resulting cuttillg rate of the wires through the diamond was approximately 1 mm3 /hour. The resulting cut was a very clean one.
O
Claims
THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS :
1.
A method of cutting a material utilizing a pair of spaced elect-rodes presenting parallel, elongate and spaced edges including the steps of placing the edges close to or in contact with the material, applying a voltage across the electrodes to produce a spark between the edges, and causing relative movement between the electrode edges and the material as the spark erodes the material to effect the cut.
2.
A method according to claim 1 wherein each electrode consists of a wire.
3.
A method according to claim 2 wherein the wires lie in the same plane as the direction of the relative movement.
4.
A method according to claim 2 wherein the wires lie in a plane which is transverse to the direction of the relative movement.
5.
A method according to claim 1 wherein the material is an insulating material.
6.
A method according to claim 2 wherein the material is an insulating material.
7.
A method according to claim 1 wherein the voltage applied across the wires is in the range 500 volts to 20,000 volts.
8.
A method according to claim 1 wherein the relative movement is effected by keeping the material stationary and moving the electrode edges through the material in the direction of cut by applying a load to the electrodes.
9.
A method according to claim 1 wherein the relative movement is effected by keeping the electrodes stationary and moving the material towards the electrodes.
10.
A method of cutting a material including the steps of placing a pair of spaced wires close to or in contact with the material, applying a voltage in the range of 500 to 20,000 volts across the wires to produce a spark across the wires, and causing the wires to move through the material as the spark erodes the material to effect the cut.
11.
A method according to claim 10 wherein the material is diamond.
12.
Apparatus for cutting a material including a pair of spaced electrodes presenting parallel, elongate and spaced edges adapted to be placed close to or in contact with the material, means to apply a voltage across the electrodes to produce a spark in a zone between the edges, and means to move the electrode edges and the material relatively to each other as the spark erodes the material to effect the cut.
13.
Apparatus according to claim 12 in which each electrode consists of a wire.
14.
Apparatus according to claim 13 which includes a feed roller and a take-up roller for each wire, and means continuously to feed fresh wire through the spark zone.
15.
Apparatus according to claim 14 in which the wires are fed in opposite directions through the spark zone.
16.
Apparatus according to claim 13 which includes means to vary the spacing between the wires in the spark zone.
17.
Apparatus according to claim 16 in which the means to vary the spacing between the wires in the spark zone comprise two spaced prongs, each prong straddling the wires and being rotatable about an axis which is transverse to the plane of the wires.
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS :
1.
A method of cutting a material utilizing a pair of spaced elect-rodes presenting parallel, elongate and spaced edges including the steps of placing the edges close to or in contact with the material, applying a voltage across the electrodes to produce a spark between the edges, and causing relative movement between the electrode edges and the material as the spark erodes the material to effect the cut.
2.
A method according to claim 1 wherein each electrode consists of a wire.
3.
A method according to claim 2 wherein the wires lie in the same plane as the direction of the relative movement.
4.
A method according to claim 2 wherein the wires lie in a plane which is transverse to the direction of the relative movement.
5.
A method according to claim 1 wherein the material is an insulating material.
6.
A method according to claim 2 wherein the material is an insulating material.
7.
A method according to claim 1 wherein the voltage applied across the wires is in the range 500 volts to 20,000 volts.
8.
A method according to claim 1 wherein the relative movement is effected by keeping the material stationary and moving the electrode edges through the material in the direction of cut by applying a load to the electrodes.
9.
A method according to claim 1 wherein the relative movement is effected by keeping the electrodes stationary and moving the material towards the electrodes.
10.
A method of cutting a material including the steps of placing a pair of spaced wires close to or in contact with the material, applying a voltage in the range of 500 to 20,000 volts across the wires to produce a spark across the wires, and causing the wires to move through the material as the spark erodes the material to effect the cut.
11.
A method according to claim 10 wherein the material is diamond.
12.
Apparatus for cutting a material including a pair of spaced electrodes presenting parallel, elongate and spaced edges adapted to be placed close to or in contact with the material, means to apply a voltage across the electrodes to produce a spark in a zone between the edges, and means to move the electrode edges and the material relatively to each other as the spark erodes the material to effect the cut.
13.
Apparatus according to claim 12 in which each electrode consists of a wire.
14.
Apparatus according to claim 13 which includes a feed roller and a take-up roller for each wire, and means continuously to feed fresh wire through the spark zone.
15.
Apparatus according to claim 14 in which the wires are fed in opposite directions through the spark zone.
16.
Apparatus according to claim 13 which includes means to vary the spacing between the wires in the spark zone.
17.
Apparatus according to claim 16 in which the means to vary the spacing between the wires in the spark zone comprise two spaced prongs, each prong straddling the wires and being rotatable about an axis which is transverse to the plane of the wires.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| ZA755666A ZA755666B (en) | 1975-09-04 | 1975-09-04 | Improvements in spark erosion |
| ZA761744 | 1976-03-22 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1068791A true CA1068791A (en) | 1979-12-25 |
Family
ID=27131129
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA260,567A Expired CA1068791A (en) | 1975-09-04 | 1976-09-03 | Spark erosion by two parallel spaced wire electrodes |
Country Status (12)
| Country | Link |
|---|---|
| US (1) | US4103137A (en) |
| JP (1) | JPS608200B2 (en) |
| CA (1) | CA1068791A (en) |
| CH (1) | CH610795A5 (en) |
| DE (1) | DE2637432A1 (en) |
| FR (1) | FR2322690A1 (en) |
| GB (1) | GB1517401A (en) |
| IE (1) | IE43938B1 (en) |
| IL (1) | IL50327A (en) |
| IT (1) | IT1071435B (en) |
| NL (1) | NL181853C (en) |
| SE (1) | SE434475B (en) |
Families Citing this family (20)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4193852A (en) * | 1977-06-14 | 1980-03-18 | Inoue-Japax Research Incorporated | Method and apparatus for electrical machining with a multi-guided travelling electrode |
| CH631371A5 (en) * | 1978-06-29 | 1982-08-13 | Diamond Sa | PROCESS FOR MACHINING A POLYCRYSTALLINE SYNTHETIC DIAMOND PART WITH METALLIC BINDER. |
| IE48798B1 (en) * | 1978-08-18 | 1985-05-15 | De Beers Ind Diamond | Method of making tool inserts,wire-drawing die blank and drill bit comprising such inserts |
| US4243864A (en) * | 1979-01-15 | 1981-01-06 | Vieau Richard R | Multiple wire electrode feed mechanism for electroerosion machine |
| IE53484B1 (en) * | 1981-02-13 | 1988-11-23 | Redland Roof Tiles Ltd | Wire electrode spark erosion |
| DE3122429A1 (en) * | 1981-06-05 | 1982-12-30 | Lach-Spezial-Werkzeuge Gmbh, 6450 Hanau | METHOD AND DEVICE FOR GRINDING TOOLS |
| DE3128403A1 (en) * | 1981-07-17 | 1983-02-03 | Lach-Spezial-Werkzeuge Gmbh, 6450 Hanau | Process and device for regrinding diamond tools |
| US4475996A (en) * | 1982-03-03 | 1984-10-09 | Inoue-Japax Research Incorporated | Multi-strand wire electroerosion machining method and apparatus |
| US4463241A (en) * | 1982-06-28 | 1984-07-31 | General Electric Company | Fixture for electrode wire EDM apparatus |
| JPS5942224A (en) * | 1982-09-02 | 1984-03-08 | Hitachi Seiko Ltd | Electric discharge machining |
| JPS6029234A (en) * | 1983-07-11 | 1985-02-14 | Mitsubishi Electric Corp | Wire electrode for wire cut electrical discharge machining |
| JPS61161097U (en) * | 1985-03-28 | 1986-10-06 | ||
| US4772788A (en) * | 1985-12-25 | 1988-09-20 | Nippon Paint Co., Ltd. | Corona discharge treating system |
| JPS63159445A (en) * | 1986-12-23 | 1988-07-02 | Nippon Paint Co Ltd | Corona discharge treatment apparatus |
| DE3942604A1 (en) * | 1989-12-22 | 1991-06-27 | Berkenhoff Gmbh | WIRE ELECTRODE ARRANGEMENT FOR SPARK-EDM CUTTING AND METHOD FOR THE PRODUCTION THEREOF |
| DE10312773A1 (en) * | 2003-03-23 | 2004-10-21 | Rennebeck, Klaus, Dr. | Manufacture of electrically conductive microfilms, microfibres, hollow micro-fibers, nano-particles and microparticles of diamond or silicon |
| CN100388998C (en) * | 2006-07-06 | 2008-05-21 | 上海交通大学 | Horizontally wire-feeding split type micro electric spark wire cutting device |
| US7816619B2 (en) * | 2007-03-21 | 2010-10-19 | Nebojsa Jaksic | Methods and apparatus for manufacturing carbon nanotubes |
| US20100140226A1 (en) * | 2008-12-08 | 2010-06-10 | Dong-Yea Sheu | Tandem micro electro-discharge machining apparatus |
| WO2015181681A1 (en) * | 2014-05-27 | 2015-12-03 | Luca Toncelli | Multiwire frame for cutting blocks of stone or stone-like material into slabs |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2552582A (en) * | 1946-12-23 | 1951-05-15 | Chauncey G Peters | Dry drilling of diamonds and the like |
| US2635487A (en) * | 1949-06-03 | 1953-04-21 | Gen Cable Corp | Method and apparatus for making wire drawing dies |
| FR1031411A (en) * | 1951-01-25 | 1953-06-23 | Csf | Diamond drilling machine and the like |
| FR1094969A (en) * | 1953-11-28 | 1955-05-25 | New process for drilling precious stones | |
| US2939941A (en) * | 1957-03-20 | 1960-06-07 | Heerschap Matthys | Eroding of hard crystalline carbon |
| DE1153313B (en) * | 1957-03-20 | 1963-08-22 | Ind Distributors 1946 Ltd | Process for the electrical discharge machining of a diamond body |
| US4013863A (en) * | 1973-02-07 | 1977-03-22 | U.S. Philips Corporation | Method of finishing a workpiece of a non-conducting material, particularly diamond, by means of spark erosion |
-
1976
- 1976-08-18 IE IE1827/76A patent/IE43938B1/en unknown
- 1976-08-20 GB GB34911/76A patent/GB1517401A/en not_active Expired
- 1976-08-20 IL IL50327A patent/IL50327A/en unknown
- 1976-08-20 DE DE19762637432 patent/DE2637432A1/en active Granted
- 1976-08-27 FR FR7626436A patent/FR2322690A1/en active Granted
- 1976-08-30 US US05/718,472 patent/US4103137A/en not_active Expired - Lifetime
- 1976-08-31 SE SE7609617A patent/SE434475B/en not_active IP Right Cessation
- 1976-09-02 CH CH1111676A patent/CH610795A5/xx not_active IP Right Cessation
- 1976-09-02 IT IT69138/76A patent/IT1071435B/en active
- 1976-09-02 NL NLAANVRAGE7609805,A patent/NL181853C/en not_active IP Right Cessation
- 1976-09-03 CA CA260,567A patent/CA1068791A/en not_active Expired
- 1976-09-03 JP JP51105655A patent/JPS608200B2/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5252291A (en) | 1977-04-26 |
| IE43938L (en) | 1977-03-04 |
| GB1517401A (en) | 1978-07-12 |
| FR2322690B1 (en) | 1982-04-09 |
| SE7609617L (en) | 1977-03-05 |
| IE43938B1 (en) | 1981-07-01 |
| FR2322690A1 (en) | 1977-04-01 |
| NL181853B (en) | 1987-06-16 |
| US4103137A (en) | 1978-07-25 |
| CH610795A5 (en) | 1979-05-15 |
| JPS608200B2 (en) | 1985-03-01 |
| IL50327A (en) | 1979-09-30 |
| IT1071435B (en) | 1985-04-10 |
| NL181853C (en) | 1987-11-16 |
| DE2637432A1 (en) | 1977-03-17 |
| SE434475B (en) | 1984-07-30 |
| NL7609805A (en) | 1977-03-08 |
| DE2637432C2 (en) | 1987-11-19 |
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