JP2003039243A - Method and apparatus for electric discharge machining - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric discharge machining method and apparatus using machining medium containing powder mixed into machining fluid, by which abnormal discharge and the like in finish machining can be prevented and productivity becomes high because machining processes after changing the machining medium is not complex. SOLUTION: In the electric discharge machining apparatus for machining a workpiece 2 by supplying electric discharge energy between an electrode 1 immersed in machining medium in a machining vessel 3 and the workpiece 2 by means of a machining electric power supplying means and by relatively moving the electrode 1 and the workpiece 2 by means of a positioning means, the electric discharge machining apparatus comprises a first machining medium supply means for supplying a first machining medium 11, which contains a first powdered substance 6 mixed into machining fluid, into the machining vessel 3, and a second machining medium supply means for supplying a second machining medium 21, which contains a second powdered substance 7 mixed into machining fluid, into the machining vessel 3, wherein the first machining medium 11 and the second machining medium 21 are selected so that the distance between the discharge electrodes in the first machining medium 11 is almost the same as that in the second machining medium 21.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in an electric discharge machining method and apparatus for machining a workpiece in a machining medium in which a powder of metal or semiconductor is mixed in a machining fluid.

[0002]

2. Description of the Related Art Metals or semiconductors (Ge, S
(i, Gr, Al, etc.) is used as a machining medium, and the machining medium is interposed in the gap between the electrode and the workpiece to perform electric discharge machining. It is known that, particularly in finishing, effects such as stabilization of processing, improvement of surface roughness, large-area mirror-finishing, and modification of surface layer can be obtained due to the dispersion of the above.

In electric discharge machining using a machining medium in which a powder is mixed in the machining fluid, if machining chips (for example, a particle size of about 50 to 100 μm) generated during rough machining are mixed with the powder, the electrode and the surface of the electrode are not covered during the finishing machining. The machining waste is caught in the gap between the workpiece and the workpiece, causing abnormal discharge such as electric discharge concentration or mechanical damage on the machined surface, and it is not possible to obtain a uniform finished surface.

As measures for preventing abnormal discharge and mechanical damage to the machined surface during such finishing, there are, for example, the following two conventional techniques.

The first conventional technique is, for example, Japanese Patent Laid-Open No. 3-27.
The first processing medium disclosed in Japanese Patent No. 7421, which does not contain powder during roughing, uses the second processing medium containing powder during finishing, and uses a filtering device such as a paper filter during roughing. Is operated at all times or intermittently to remove large processing scraps generated during rough processing, and the filtration device is not normally operated during finish processing. The filtration of the second processing medium for finish processing makes it difficult to obtain the effect of stabilizing the processing with powder or improving the surface roughness, or the effect of large-area mirror processing or modification of the surface layer. In this case, it is performed automatically or manually by an operator, depending on the detection by a sensor for measuring the deterioration of the powder or the life time based on the durability test of the powder.

The second prior art is, for example, Japanese Patent Laid-Open No. 7-10.
The processing waste adsorption device (so-called magnet filter device) made of a magnetic material disclosed in Japanese Patent No. 8419 is used. In this method, since the same machining medium can be used for both rough machining and finishing machining, the above-mentioned machining process which needs to be prepared for switching the machining medium is unnecessary, and the machining process is simplified.

[0007]

[Patent Document 1] Japanese Patent Application Laid-Open No. 3-27742
In the method disclosed in Japanese Patent Laid-Open No. 1, when the distance between the discharge electrodes at the time of rough machining is different from that at the time of finish machining, the distance between the discharge electrodes is changed when the machining medium is switched and the finish machining is started at the time of transition from rough machining to finish machining. If a machining process that takes into account the difference is not provided, the machining amount of the workpiece and the electrode consumption increase.

FIG. 8 is an explanatory view of an increase in processing amount and electrode consumption of the workpiece, in which 1 is an electrode and 1a.
Is an electrode consumable part, 2 is a workpiece, 2a is a part to be additionally processed at the time of finishing, G1 is a distance between discharge electrodes at the time of roughing, and G1 is
2 is the distance between the discharge electrodes at the time of finishing, and Gd is the difference between the distances between the discharge electrodes at the time of rough processing and at the time of finishing.

When a machining medium (first machining medium) containing no powder is used during rough machining and a machining medium (second machining medium) containing powder during finishing is used, the discharge electrode during finishing machining is used. The distance G2 is larger than the distance G1 between the discharge electrodes during rough machining.

In such a case, if the machining process considering the difference in the distance between the discharge electrodes is not provided, that is, if the finishing process is performed in the same machining radius and the like as the rough machining,
Excessive machining is performed by the difference Gd between the discharge electrode distances during rough machining and finish machining due to the difference between the first machining medium and the second machining medium (portion 2a in the figure). Also, the electrode 1
Also increases (part 1a in the figure).

In order to prevent such an increase in the amount of machining of the workpiece and the consumption of electrodes, the distance between the discharge electrodes during rough machining and finish machining after switching between the first machining medium and the second machining medium. It is also possible to provide a processing step in which the swing radius and the electrode feed amount are reduced in consideration of the difference Gd between
It is necessary to prepare a large number of such processing steps corresponding to the processing shapes, which causes a problem of complicating the processing steps.

Further, according to the method disclosed in Japanese Patent Laid-Open No. 7-108419, the processing scraps of the magnetic material can be effectively removed. However, since about 70% of the processing scraps are non-magnetic materials, the processing scraps are 70% cannot be removed. Therefore, in order to eliminate the processing dust that cannot be removed by the magnet filter device by this method or to replace the deteriorated powder with a new powder for a long-term use, the filtration of the processing medium by a filtering device such as a paper filter is regularly performed. However, there is a problem in that processing cannot be performed during such filtration of the processing medium (which requires about 2 to 3 hours, and it takes more time for a larger processing tank).

The present invention has been made to solve the above-mentioned problems, and in electric discharge machining using a machining medium in which a powder is mixed in a machining fluid, an abnormal electric discharge at the time of finish machining and mechanical surface machining It is an object of the present invention to provide an electric discharge machining method and apparatus capable of preventing damage and stably obtaining a uniform finished surface.

Further, it is possible to suppress an increase in the machining amount and electrode consumption of the workpiece when the machining medium is switched to change from rough machining to finish machining, and after switching between the first machining medium and the second machining medium. It is an object of the present invention to obtain an electric discharge machining method and device which do not complicate the machining process of.

Another object of the present invention is to obtain an electric discharge machining method and apparatus with high productivity.

[0016]

The electric discharge machining method according to the present invention is an electric discharge machining method in which electric discharge energy is supplied between the electrode and a workpiece to perform machining. A first machining step in which electric discharge machining is performed in a first machining medium in which is mixed, and a second machining step in which electric discharge machining is performed in a second machining medium in which a second powder is mixed in a machining fluid. The first machining medium and the second machining medium are arranged such that the distances between the discharge electrodes are equal to each other.
The processing medium and the second processing medium are selected.

Further, the electric discharge machining method according to the present invention is the electric discharge machining method in which electric discharge energy is supplied between the electrode and the workpiece to perform machining, in which the first powder is mixed in the machining fluid. A first machining step of performing electric discharge machining in a first machining medium and a second machining step of performing electric discharge machining in a second machining medium in which a first powder is mixed in a machining fluid, The powder concentration of the first processing medium and the powder concentration of the second processing medium are selected within the range of the powder concentration in which the change in the distance between the discharge electrodes due to the powder concentration of the first powder with respect to the liquid is small. It is a thing.

Further, the electric discharge machining method according to the present invention comprises a step of filtering a machining medium in one of the first machining medium and the second machining medium while processing the other machining medium. It is a thing.

In the electric discharge machining apparatus according to the present invention, the machining energy is supplied between the electrode immersed in the machining medium and the workpiece in the machining tank by the machining power supply means, and the positioning means is used to discharge the electrode and the workpiece. In an electric discharge machine for machining a workpiece by moving a workpiece relative to the workpiece,
A first processing medium supply means for supplying a first processing medium mixed with the powder of No. 1 to the processing tank, and a second processing medium supplying a second processing medium having a second powder mixed in the processing liquid to the processing tank. A second machining medium supply means, so that the distances between the discharge electrodes in the first machining medium and the second machining medium are equal to each other. The medium is selected.

Further, in the electric discharge machining apparatus according to the present invention, the machining energy is supplied between the electrode immersed in the machining medium and the workpiece in the machining tank by the machining power supply means, and the positioning means is used for the electrode. And an electric discharge machining apparatus for machining a workpiece by relatively moving the workpiece, supplying a first machining medium in which a first powder is mixed in a machining fluid to the machining tank. Means and a second processing medium supply means for supplying a second processing medium in which the first powder is mixed into the processing liquid to the processing tank, and the second processing medium supply means for adjusting the powder concentration of the first powder to the processing liquid. The powder concentration of the first working medium and the powder concentration of the second working medium are selected within the range of the powder concentration in which the change in the distance between the discharge electrodes is small.

Further, in the electric discharge machining apparatus according to the present invention, the machining energy is supplied between the electrode immersed in the machining medium and the workpiece in the machining tank by the machining power supply means, and the positioning means is used for the electrode. A first machining medium supply means for supplying a first machining medium in which a powder is mixed in a machining fluid to the machining tank in an electric discharge machine for machining the workpiece by relatively moving the machining object, A second processing medium supply means for supplying a second processing medium, which is the same processing medium as the first processing medium, to the processing tank.

The electric discharge machine according to the present invention further comprises a first machining medium filtering means for filtering the first machining medium and a second machining medium filtering means for filtering the second machining medium. It is a thing.

Further, the electric discharge machining apparatus according to the present invention comprises machining medium filtering means for filtering the first machining medium and the second machining medium.

Further, the electric discharge machining apparatus according to the present invention comprises a control means for controlling the driving of the machining medium filtering means by code setting of the NC program.

[0025]

1 is a block diagram of an electric discharge machine according to an embodiment of the present invention. In the figure, 1 is an electrode, 2 is a workpiece, 3 is a processing tank, and 4 is a first. Processing, for example, processing powder generated during rough processing, 5 is processing powder generated during second processing, for example, finishing processing, and 6 and 7 are, for example, in the range of 0.1 to several tens of μm in average particle size. Powders of metals, semiconductors, etc., such as Ge, Si, Gr, Al, etc.

Reference numeral 11 denotes a first machining medium supplied to the machining tank 3 during the first machining, for example, rough machining, 12 a machining medium accommodating means for accommodating the first machining medium 11, and 12a a machining tank 3.
A sewage tank for containing the sewage collected from the sewage tank, 12b is a sewage tank for storing the processing medium which has been cleaned by precipitating the processing powder in the sewage tank 12a to some extent, 12c is a sewage tank 12a and a sewage tank. It is a separation wall for separating 12b. This separation wall is a waste tank 1
It is sufficient if the processed powder is precipitated to some extent in 2a and the cleaned processing medium flows into the clean liquid tank 12b. Therefore, the separation wall 12c
Therefore, rather than completely separating the waste liquid tank 12a and the clean liquid tank 12b, it is preferable to set the height of the separation wall 12c to a height at which the waste liquid and the clear liquid of the clear liquid can come and go as shown in FIG. 13 and 14 are control valves. The control valve 13 is for drain during rough machining, and is the first drained from the machining tank 3 during the first machining.
The processing medium 11 is flowed into the processing medium accommodation means 12 and collected. A pump 15 is attached to the processing medium accommodating means 12 and is connected to the processing tank 3 via a control valve 14.
The pump 16 is for batch processing of powder, and is attached to the processing medium accommodating means 12 so as to remove the powder and the processing powder in the waste liquid tank 12 a via the processing medium filtering means 17. Reference numeral 18 is a powder supply means to the first processing medium 11. First of processing medium accommodating means 12 and pump 15
The apparatus for supplying the processing medium 11 of
Corresponds to the processing medium supply means.

Reference numeral 21 is a second processing medium supplied to the processing tank 3 during second processing, for example, finishing processing, and 22, 2
Reference numerals 2a, 22b, and 22c denote a processing medium accommodating means, a sewage tank, a cleansing liquid tank, and a separation wall of the second processing medium 21, respectively. 23 and 24 are control valves. The control valve 23 is for draining during the finishing process, and the second machining medium 21 discharged from the machining tank 3 during the second machining flows into the machining medium accommodating means 22 and is collected. A pump 25 is attached to the processing medium accommodating means 22 and is connected to the processing tank 3 via a control valve 24. Further, the pump 26 is for batch processing of powder, and the waste fluid tank 22a is provided via the processing medium filtering means 27.
It is attached to the processing medium accommodating means 22 so as to remove the powder and the processing powder therein. 28 is the second processing medium 21
Is a means for supplying powder to the. An apparatus for supplying the second processing medium 21 such as the processing medium accommodation means 22 and the pump 25 to the processing tank 3 corresponds to the second processing medium supply means.

Further, the relative positioning between the electrode 1 and the workpiece 2 is performed by the electrode 1 (not shown) which is usually used in an electric discharge machine.
It is performed by a positioning means including a Z-axis and an XY table for driving the workpiece. The machining power, which is not shown, is supplied to the gap between the electrode 1 and the workpiece 2 by the machining power supply means (not shown), and the workpiece The electric discharge machining of the object 2 proceeds.
The relative positioning control of the electrode 1 and the workpiece 2 by the positioning means, the control of electrical conditions, etc. are integrated by the control means (not shown).

First working medium 11 and second working medium 21
Is the same as the distance between the discharge electrodes. That is,
When the processing medium 11 at the time of the first processing and the processing medium 21 at the time of the second processing are the same, or when the processing medium 11 at the time of the first processing and the processing medium 21 at the time of the second processing are changed. However, a material having a short distance between the discharge electrodes is used.

FIG. 2 shows a change in the distance G between the discharge electrodes depending on the powder concentration in the processing medium under the same processing conditions.
This is an example in the case of selecting a processing medium 21 having a short distance between the discharge electrodes at the time of processing. In FIG. 2, A and B are powder concentrations, GA and GB are discharge electrode distances when the powder concentrations are A and B, respectively, and G0 is a discharge electrode distance when no powder is mixed. As you can see from Figure 2,
The distance G between the discharge electrodes greatly changes (for example, G0 and GA) depending on the presence or absence of powder mixture (for example, when the powder concentration is 0 and when the powder concentration is A). In the comparison between the mixed substances, the change in the distance G between the discharge electrodes due to the powder concentration is small (GA and GB). That is, there is a powder concentration range in which the distance G between the discharge electrodes does not change much depending on the powder concentration in the processing medium (C in FIG. 2). For example, the powder concentration A within the powder concentration range C in which the change in the distance G between the discharge electrodes due to the powder concentration in the processing medium is small is selected as the powder concentration of the first processing medium, and the powder concentration B is determined as the first concentration. If the powder concentration of the second processing medium is selected, the distance between the discharge electrodes of the processing medium 11 during the first processing and the processing medium 21 during the second processing can be reduced.

The powder concentration in the working medium for controlling the powder concentration can be measured by measuring the weight of the working medium having a predetermined volume.

As described above, the first working medium 11 and the second working medium 11
By setting the distances between the discharge electrodes of the machining medium 21 to be equal, correction of the swing radius and the electrode feed amount at the time of switching the machining medium can be eliminated.

Next, the operation of the electric discharge machine according to the present invention will be described. FIG. 3 shows the flow of the first working medium 11 during the first working. As the first working medium 11, as described above, the distance between the discharge electrodes is the second working medium 2.
The same as 1 is used. The first processing medium 11 in the processing medium accommodating means 12 is in a state in which the powder 6 is mixed by the operator or the powder supplying means 18. The first processing medium 11 is pumped up from the clean liquid tank 12b by the pump 15 and supplied to the processing tank 3. The processing medium in the processing tank 3 used for processing is collected in the sewage tank 12a through the drain control valve 13, and then the processing powder 4 during the first processing is precipitated in the sewage tank 12a. After that, the processed powder 4 is supplied to the processing tank 3 by the pump 15 from the clean liquid tank 12b that does not contain much.

Normally, the powder 6 thus mixed in the machining medium is repeatedly used for electric discharge machining. However, when electric discharge machining is repeated for a long time, the machining powder in the machining medium increases and the powder 6 deteriorates. However, the processing characteristics deteriorate. When the powder 6 reaches the end of its life or when the processing characteristics are deteriorated by the processing powder 4, as shown in FIG. 4, the pump 16 is operated and the processing medium filtering means 17 filters the first processing medium 11. Thus, the powder 6 and the processed powder 4 are removed. After the first processing medium 11 is filtered by the processing medium filtering means 17 in this way, the worker or the powder supply means 11 is added to the clean processing medium stored in the clean liquid tank 12b in the processing medium accommodating means 12. Thus, new powder 6 is supplied and a new first processing medium 11 is prepared.

Next, the operation during the second processing will be described. FIG. 5 shows the flow of the second working medium 21 during the second working, and the second working medium 21 has the same distance between the discharge electrodes as the first working medium 11 as described above. belongs to.
The second processing medium 21 in the processing medium accommodation means 22 is in a state in which the powder 7 is mixed by the operator or the powder supply means 28. The second processing medium 21 is pumped up from the clean liquid tank 22b by the pump 25 and supplied to the processing tank 3. The processing medium in the processing tank 3 used for processing is collected in the sewage tank 22a through the drain control valve 23, and then the processing powder 5 in the second processing is precipitated in the sewage tank 22a. After that, the processed powder 5 is supplied to the processing tank 3 by the pump 25 from the clean liquid tank 22b that does not contain much.

Normally, the powder 7 mixed in the machining medium in this manner is repeatedly used for electric discharge machining. However, when electric discharge machining is repeated for a long time, the machining powder in the machining medium increases and the powder 7 deteriorates. However, the processing characteristics deteriorate. When the powder 7 reaches the end of its life or when the processing characteristics are deteriorated by the processing powder 5, as shown in FIG. 6, the pump 26 is operated and the processing medium filtering means 27 filters the second processing medium 21. By doing so, the powder 7 and the processed powder 5 are removed. After the second processing medium 21 is filtered by the processing medium filtering means 27 in this way, the clean processing medium stored in the clean liquid tank 22b in the processing medium accommodating means 22 is treated by the operator or the powder supply means 21. Fresh powder 7 is supplied to prepare new finishing media. In the case where the second processing is finish processing, the life of the powder 7 is relatively long in the finish processing as compared with the rough processing, and the production amount of the processed powder 5 is small. Alternatively, it may be removed in a batch process.

As described above, by dividing the processing medium supply means between the first processing which is, for example, rough processing and the second processing which is, for example, finishing processing (first processing medium supply means and second processing). (Medium supplying means), since it is possible to prevent the processing waste having a large particle diameter generated in the roughing from being mixed into the processing medium used in the finishing, it is possible to stably obtain a uniform finished surface.

Further, since the first machining medium 11 and the second machining medium 21 have the same distance between the discharge electrodes, when the machining medium is switched and the rough machining is changed to the finishing machining. It is possible to suppress an increase in the processing amount of the workpiece and the consumption of the electrode, and it is possible to simplify the processing process. Therefore, the design cost of the processing process can be reduced.

FIG. 7 is an explanatory view showing a comparative example of the processing step of the present invention and the processing step in the case where there is one processing medium supply means which is a conventional technique. In the machining step (A in the figure) in the case where there is one machining medium supply means, which is a conventional technique, the powder replacement time is approaching after the electric discharge machining using the first machining medium in which the powder is mixed in the machining liquid, When the electric discharge machining is continuously performed, the machining cannot be performed during the filtration time of the first machining medium (usually 2 to 3 hours, which becomes longer as the machining tank becomes larger). On the other hand, according to the machining step (B in the figure) of the present invention, after the electric discharge machining using the first machining medium in which the powder is mixed in the machining liquid, the powder replacement time is approaching and the electric discharge machining is continuously performed. In the case of performing, the electric discharge machining using the second machining medium in which the powder is mixed in the machining fluid can be performed in parallel with the filtration of the first machining medium, so that the next step work can be started sooner. And the operation rate of the electric discharge machine is improved. Therefore, productivity can be improved.

Further, in the present invention, since the processing medium can be filtered without circulating the processing medium in the processing tank,
Positioning work and paralleling work of the electrode and the work can be performed during filtration of the working medium.

When filtering the processing medium in each processing medium accommodating means, for example, the following method can be considered. That is, as a first method, for example, a "first processing medium filtering button" and a "second processing medium filtering button" are provided on the operation screen, and by pressing this button, the corresponding processing medium accommodation means The second method is to filter the processing medium, and the second method is to have a control means for controlling the driving of the processing medium filtering means 17 and 27 by setting the code of the NC program. According to the second method, automation of electric discharge machining according to the present invention can be realized.

In the above description, the first working medium 1
The case where the processing medium filtering means 17 for 1 and the processing medium filtering means 27 for the second processing medium 21 are provided has been described, but the processing medium and the processing medium supplied as one processing medium filtering means to the processing medium filtering means are described. A configuration in which the processing medium discharged from the medium filtering means is switched by a control valve may be adopted.

[0043]

Since the electric discharge machining method and apparatus according to the present invention are configured as described above, the following effects can be obtained.

Since the machining medium supply means is divided between the roughing process and the finishing process, it is possible to suppress the mixing of the machining waste having a large grain size generated in the roughing process into the machining medium used in the finishing process. Therefore, since it is possible to prevent abnormal discharge during finishing and mechanical damage to the machined surface, it is possible to stably obtain a uniform machined surface.

Further, since the first machining medium and the second machining medium have the same distance between the discharge electrodes, the workpieces to be machined when the machining medium is switched and the rough machining is changed to the finishing machining. It is possible to suppress an increase in the processing amount of the object and the consumption of the electrode, and it is possible to simplify the processing process. Therefore, the design cost of the processing process can be reduced.

Further, since the processing medium in one of the first processing medium and the second processing medium can be filtered while the other processing medium is processed, the productivity is improved.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an electric discharge machine according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a change in distance between discharge electrodes depending on a powder concentration in a processing medium under the same processing conditions.

FIG. 3 is an operation explanatory diagram showing a flow of a first processing medium at the time of first processing.

FIG. 4 is an operation explanatory view of processing medium filtering by the processing medium filtering unit during the first processing.

FIG. 5 is an operation explanatory view showing a flow of a second processing medium at the time of second processing.

FIG. 6 is an operation explanatory view of the processing medium filtering by the processing medium filtering means during the second processing.

FIG. 7 is an explanatory diagram showing a comparative example of a processing step according to the present invention and a processing step in the case where there is one processing medium supply unit which is a conventional technique.

FIG. 8 is an explanatory diagram of an increase in machining amount of a workpiece and electrode consumption in the case where a machining process is switched and rough machining is changed to finish machining, and a machining process considering the difference in discharge electrode distance is not provided. Is.

[Explanation of symbols]

1 electrode, 2 workpieces, 3 processing tanks, 6 and 7 powders,
11 first working medium, 12 working medium accommodating means, 1
3, 14 control valve, 15, 16 pump, 17 processing medium filtering means, 18 powder supply means, 21 second processing medium, 22 processing medium accommodating means, 23, 24 control valve, 2
5, 26 pump, 27 processing medium filtering means, 28 powder feeding means.

Claims (9)

[Claims] 1. A method of electric discharge machining for supplying electric discharge energy between an electrode and a workpiece to perform electric discharge machining in a first machining medium in which a first powder is mixed in a machining fluid. A first machining step to be performed, and a second machining step to perform electric discharge machining in a second machining medium in which a second powder is mixed in a machining fluid, the first machining medium and the second machining step. The electric discharge machining method, wherein the first machining medium and the second machining medium are selected so that the distances between the discharge electrodes in the machining medium are the same. 2. An electric discharge machining method in which electric discharge energy is supplied between electrodes and a workpiece to perform machining, in which electric discharge machining is performed in a first machining medium in which a first powder is mixed in a machining fluid. A first machining step to be performed, and a second machining step to perform electric discharge machining in a second machining medium in which the first powder is mixed in the machining fluid, wherein the powder of the first powder with respect to the machining fluid An electric discharge machining method, characterized in that the powder concentration of the first machining medium and the powder concentration of the second machining medium are selected within a powder concentration range in which the change in the distance between the discharge electrodes due to the concentration is small. 3. The method according to claim 1, further comprising a step of filtering a processing medium in one of the first processing medium and the second processing medium during a processing step in the other processing medium. Or the electric discharge machining method according to 2. 4. A discharge energy is supplied by a machining power supply means between the electrode and the workpiece, which are immersed in the machining medium in the machining tank, and the positioning means relatively moves the electrode and the workpiece. In an electric discharge machining device for machining the workpiece, a first machining medium supply means for supplying a first machining medium in which a first powder is mixed in a machining fluid to the machining tank, and a second machining medium for supplying the machining fluid to the machining tank. A second machining medium supply means for supplying a second machining medium mixed with the powder of No. 1 to the machining tank, wherein the distance between the discharge electrodes in the first machining medium and the second machining medium is An electric discharge machining apparatus, characterized in that the first machining medium and the second machining medium are selected so as to be equivalent. 5. A discharge energy is supplied by a machining power supply means between the electrode and the workpiece, which are immersed in the machining medium in the machining tank, and the positioning means relatively moves the electrode and the workpiece. In an electric discharge machining device for machining the workpiece, a first machining medium supply means for supplying a first machining medium in which a first powder is mixed into the machining fluid to the machining tank, and a first machining medium in the machining fluid. A second processing medium supply means for supplying a second processing medium mixed with the powder of No. 1 to the processing tank, wherein the change in the distance between the discharge electrodes due to the powder concentration of the first powder with respect to the processing liquid is small. An electric discharge machining apparatus, wherein the powder concentration of the first machining medium and the powder concentration of the second machining medium are selected within a concentration range. 6. A discharge energy is supplied by a machining power supply means between the electrode and the workpiece immersed in the machining medium in the machining tank, and the positioning means relatively moves the electrode and the workpiece. In an electric discharge machining apparatus for machining the workpiece, a first machining medium supply means for supplying a first machining medium in which a powder is mixed in a machining fluid to the machining tank, and the same machining as the first machining medium. An electric discharge machining apparatus comprising: a second machining medium supply means for supplying a second machining medium, which is a medium, to the machining tank. 7. A first processing medium filtering means for filtering the first processing medium and a second processing medium for filtering the second processing medium.
5. The processing medium filtering means according to claim 4 is provided.
The electric discharge machine according to any one of 1 to 6. 8. The electric discharge machining apparatus according to claim 4, further comprising a machining medium filtering unit that filters the first machining medium and the second machining medium. 9. The drive control of the processing medium filtering means is NC.
9. The electric discharge machining apparatus according to claim 7, further comprising control means for performing code setting of a program.