JP2000042834A - Electrical discharge machining device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a machining efficiency by discharging sludge efficiently from a machining part under electrical discharge machining. SOLUTION: This device is composed of a machining electrode 10 and a discharge power source 33 for applying a voltage pulse between it and a work 2 where a machining part is to be installed, and has a machining vessel 15 filled with machining liquid 150 in which the work 2 is installed. The machining electrode 10 is given a camber having a constant curvature or a camber having a constant angle, and composed rotatably relative to the work 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a nozzle injection hole, an orifice,
The present invention relates to an electric discharge machining apparatus used for machining a through hole or a groove forming a press die, a honeycomb structure forming die, or the like, particularly when high precision is required.

[0002]

2. Description of the Related Art In some cases, electric discharge machining is used to produce machining portions such as nozzle holes, orifices, press die, and die for forming a honeycomb structure.
In this electric discharge machining, a voltage pulse is applied between the machining electrode and the work to be machined by the electric discharge power source, an electric discharge is generated between them, and the unnecessary part of the work is removed in a shape along the electrode and machined. This is a processing method for forming a portion.

In the above-mentioned electric discharge machining, a work is placed in a machining liquid, and a machining electrode is advanced with respect to the work until electric discharge occurs. Also, when the machining electrode contacts the workpiece,
Alternatively, when the machining electrode comes into contact with the workpiece via sludge (swarf) generated by the machining, the machining electrode is retracted from the workpiece. With such a mechanism, the distance between the machining electrode and the workpiece is always maintained in an optimum state, and a continuous discharge is generated between the two.

When the machining electrode comes into contact with the workpiece,
A short circuit or concentrated discharge is caused between the two, and the electric discharge machining stops there. Therefore, quickly discharging sludge generated by machining from the machining section is an effective means for increasing machining speed and improving machining accuracy.

[0005] Techniques for improving the sludge discharge property include methods of using a pipe-shaped machining electrode, vibrating the machining electrode, rotating the machining electrode, and spraying a machining fluid from outside to the machining portion. Can be mentioned.

[0006]

However, the prior art described above has a problem that the following problem may occur when manufacturing a fine processed portion. First, a method using a pipe-shaped machining electrode is a pipe-shaped machining electrode, which refers to a machining electrode provided with a machining fluid injection channel. It is configured so that sludge in the processed part can be blown off by injection.

However, in order to process a fine processing portion, it is necessary to reduce the diameter of the processing electrode, and accordingly, the diameter of the working liquid injection path must be reduced. Therefore, a very high pressure is required for injecting the working fluid, which may make it difficult to inject the working fluid. Further, it is difficult to manufacture such a fine processed electrode.

[0008] The method of vibrating the machining electrode is also known. In this method, a pump effect is generated by vibrating the machining electrode, and the sludge discharge efficiency is increased by ejecting the machining fluid from the machining portion. it can. However, when the diameter of the machining electrode is small and the rigidity is low, the machining electrode may be easily damaged. In addition, when the machining electrode having low rigidity is vibrated, the machining electrode may be shaken or bent, and the machining accuracy may be reduced, or the workpiece may be easily contacted with the workpiece, and the frequency of occurrence of short circuit may increase.

In this method, the working electrode is rotated. In this method, the working fluid is agitated by rotating the working electrode, and a flow is generated in the working fluid, thereby improving sludge discharge efficiency. it can. However, when the diameter of the processing electrode is small, it is difficult to obtain a sufficient sludge discharge effect because the power of stirring the processing liquid is weak. The problem described above often becomes a problem when the diameter of the processed portion is smaller than 200 μm, and particularly remarkably occurs when the diameter of the processed portion is smaller than 100 μm.

The present invention has been made in view of such a conventional problem, and an object of the present invention is to provide an electric discharge machining apparatus capable of efficiently increasing the machining efficiency by efficiently discharging sludge from a machining section during electric discharge machining. Things.

[0011]

According to a first aspect of the present invention, a discharge power source for applying a voltage pulse between a machining electrode and a work on which a machining portion is to be provided is provided, and the work is filled with a machining fluid for installing the work. In the electric discharge machining apparatus having a machining tank, the machining electrode is provided with a constant curvature or a constant angle, and is configured to be rotatable with respect to a workpiece.

In the electric discharge machine according to the present invention,
Any form of a processing electrode such as a thin wire, rod, thin plate, etc. can be used. As shown in FIG. 6 (a), the term "a constant curvature warp is applied" in the present invention means that the radius of curvature r is equal to the electric discharge machining in the case of the processing electrode 10 provided with a gentle and smooth warp. Means constant inside. Further, the effect of the present invention can be obtained as long as the rate of change of the radius of curvature r during electric discharge machining is within a range (discharge clearance) where the machining electrode does not touch the work. If the radius of curvature r further changes during electrical discharge machining, the effects of the present invention may not be obtained.

As shown in FIG. 6B, in the case of a machining electrode 10 having a sharply-pointed sled, the angle θ of the sled is defined by electric discharge machining. Means constant inside. In the case of such a machining electrode as well, the effect of the present invention can be obtained as long as the change rate of the angle θ during electric discharge machining is within a range (discharge clearance) where the machining electrode does not touch the work. If the angle θ changes any more during electric discharge machining, the effects of the present invention may not be obtained.

Further, as the value indicating the state of the warpage of the machining electrode, as shown in a first embodiment described later, a "warpage amount" which is a distance from the rotation axis of the machining electrode to the tip of the machining electrode can be used. . A constant curvature and constant angle warp have a constant "warp amount".

Next, the operation of the present invention will be described. The processing electrode according to the present invention is provided with a constant curvature sled.
Further, the machining electrode is configured to be able to rotate with respect to the workpiece. When performing electric discharge machining using this machining electrode, the machining fluid around the work is stirred by rotating the machining electrode with respect to the work. Therefore, the sludge generated in the processing section is entrained in the stirred processing liquid and quickly discharged to the outside of the processing section.

Further, since the processing electrode according to the present invention is provided with a warp, the distance between the rotating shaft of the processing electrode and the processing portion is increased by the amount of the warp as compared with the case where no warp is provided. (See FIGS. 2 and 7 described later). Therefore, the distance between the machining electrode and the workpiece is widened, the sludge discharge route is sufficiently secured, and the sludge is smoothly discharged. In addition, due to the warpage, a flow of the machining fluid is generated in a radial direction from the rotation axis of the machining electrode. With this flow, the sludge is more efficiently discharged from the processing section.

[0017] By improving the sludge discharge property, the contact between the machining electrode and the work through the sludge is less likely to occur.
Short-circuiting and concentrated discharge hardly occur between the processing electrode and the workpiece. Therefore, the processing speed can be increased and the processing accuracy can be improved. Furthermore, since the curvature of the processing electrode according to the present invention is constant in curvature or constant in angle, the diameter of the processing portion can be made uniform, and a processing portion excellent in cylindricity can be obtained.

As described above, according to the present invention, it is possible to provide an electric discharge machining apparatus capable of improving machining efficiency by efficiently discharging sludge from a machining portion during electric discharge machining.

Although the curvature of the processing electrode according to the present invention is constant, for example, the following method can be used to realize such a processing electrode. As one method, a method of preparing a bobbin having a constant diameter and winding and holding a metal wire such as a copper wire around the bobbin can be cited (see Embodiment 2). As a result, the metal wire is plastically deformed, and a warp having a constant curvature determined by the diameter of the bobbin is given. The working electrode according to the present invention can be constituted by such a metal wire.

The working electrode can be made of a shape memory alloy or a superelastic wire (see Embodiment 2). In this case, a desired constant curvature or constant warpage is imparted to the shape memory alloy or the superelastic wire, and this is memorized and used as a machining electrode. Such a working electrode can be once heated to a temperature at which the memory returns (transformation temperature) at the time of use, and its curvature and angle can be recovered. Also,
By maintaining the ambient temperature at the transformation temperature during electric discharge machining, it is possible to maintain a constant curvature or a constant angle of the machining electrode.

Further, the working electrode is made of a metal wire, the working electrode is attached to an electrode guide or the like, and the working electrode is protruded from the electrode guide or the like by a small amount, and a load is applied from a direction perpendicular to the protruding direction. A method of giving a warpage having a constant curvature or a constant angle by applying plastic deformation can be given (see Embodiment 1).

Since the tip of the machining electrode is worn and consumed by the above-mentioned electric discharge machining, the state of the warpage of the machining electrode is measured during the electric discharge machining, and the warping is applied again to the machining electrode according to the measurement result. It is preferable that such a mechanism be provided in the electric discharge machine. In this case, as a method of providing a warp, for example, various methods as described above can be used.

As a method of measuring the state of the warpage of the machining electrode, for example, a visual detection method using a sensor,
A contact detection method can be used. In addition, the warpage of the processing electrode can be maintained by applying the warping again to the processing electrode by feedback control according to the processing time (see Embodiment 1).

Next, as in the second aspect of the present invention, it is preferable that an electrode guide is provided on the outer periphery of the processing electrode. Thereby, it is possible to prevent the processing electrode from being deflected or bent. Therefore, a reduction in processing accuracy can be prevented.

Next, as in the third aspect of the present invention, it is preferable that an agitator configured to be rotatable with respect to the electrode guide is provided on the outer periphery of the electrode guide. Thereby, it is possible to prevent sludge discharged from the processing portion from staying on the electrode guide or the surface of the work outside the processing portion and obstructing sludge discharge from the processing portion (see Embodiment 3). .

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 shows an electric discharge machine according to an embodiment of the present invention.
This will be described with reference to FIGS. As shown in FIG. 1, the electric discharge machine 1 of the present embodiment includes a discharge power source 33 for applying a voltage pulse between the machining electrode 11 and the workpiece 2 on which the machining section 20 is to be provided.
And a processing tank 15 filled with a processing liquid 150 for installing the work 2. As shown in FIGS. 2 and 3, the processing electrode 11 is provided with a warp having a constant curvature within a range that does not touch the work 2, and is configured to be rotatable with respect to the work 2.

The details will be described below. In the electric discharge machine 1 of this embodiment, as shown in FIGS. 1 to 3, a machining electrode 10 made of a tungsten wire having a diameter of 70 μm is stored in an electrode feed box 13 in a state wound around a bobbin 101.
The electrode feed box 13 is connected to an NC shaft 14. Working electrode 10 by electrode feed box 13
Is controlled by an NC axis controller 32 connected to the NC axis 14.

The rotation of the machining electrode 10 is performed by the rotation shaft 1.
35 is performed by rotating a feeding device including the bobbin 101, and the rotating shaft 135 is configured to be driven by the rotating shaft control device 31. As shown in FIG. 3, a guide 102 is provided below the bobbin 101 to push the machining electrode 10 straight downward.

Further, as shown in FIG.
An electrode guide 11 is provided on the outer periphery of the machining electrode 1.
The vicinity of the part facing the work 2 in 1 is protected by the electrode guide 11.

As shown in FIG. 1, a machining tank 15 filled with a machining fluid 150 is disposed below the machining electrode 10, and electric discharge machining is performed in the machining tank 15. A work 2 to be processed and a jig 29 for supporting the work 2 are arranged in the processing tank 15. A dress plate 4 for regenerating the machining electrode 10 consumed by electric discharge machining is arranged near the jig 29. The application of a voltage pulse to the machining electrode 11 and the work 2 is performed by the discharge power source 3.
3 is performed. Since the application of the voltage pulse to the work 2 is performed through the processing tank 15 and the jig 29, the discharge power supply 33 is configured to supply electricity to the processing tank 15 and the processing electrode 10 in the electrode feed box 13.

As shown in FIG. 1, the processing electrode 11 according to the present embodiment is provided with a constant curvature warp, which is provided by a bending jig 14 installed in the processing tank 15. As shown in FIG. 1, the bending jig 14 is
1 and a pressing portion 142 operable with respect to the gantry 141 (see FIG. 4).

Next, an electric discharge machining method according to this embodiment will be described. As shown in FIG. 1, the work 2 is placed in the processing tank 15 using a jig 29. Subsequently, the processing liquid 150 is supplied into the processing tank 15. Next, electrode feed box 1
3 is operated, and as shown in FIG.
Is exposed from the tip of the electrode guide 11 by a fixed amount.

Next, as shown in FIG. 4B, the pressing portion 142 is driven to make contact with the exposed end of the machining electrode 10. As a result, a load is applied in the direction of the arrow shown in FIG. 4, and as shown in FIG. Subsequently, as shown in FIGS. 4D and 4E, the above operation is repeated until a desired curvature is obtained. As a result, as shown in FIG. 4F, a warp having a constant curvature is applied to the processing electrode 10.

The determination as to whether or not a desired warp has been given to the processing electrode 10 is made by an image processing apparatus connected to a visual sensor 193 installed near the processing tank 15 as shown in FIG. The bending jig 14 is operated by feedback from the image processing apparatus.

The processing electrode 10 provided with the warp as described above
Is brought close to the work 2 while being rotated using the rotation shaft 135, and the discharge power supply 33 is operated at the same time. As a result, a voltage pulse is applied between the machining electrode 10 and the work 2, and electric discharge machining is started. The machining portion 20 is formed by this electric discharge machining, and an unnecessary portion of the work 2 is removed to form sludge. The sludge is entrained in the flow of the processing liquid 150 generated by the rotation of the processing electrode 10, and is quickly discharged out of the processing unit 20.

Further, the tip of the machining electrode 10 is worn by performing the electric discharge machining. In order to regenerate the worn machining electrode 10, the machining electrode 10 is moved to the workpiece 2 every time the machining of one machining section 20 is completed or every time a certain time elapses.
, And transferred to the dress plate 4 installed in the processing tank 15. In this dress plate 4, as shown in FIG. Thereby, as shown in FIG. 5B, the tip of the machining electrode 10 can be reproduced.

The dressing is to apply a voltage pulse between the processing electrode 10 and the dress plate 4, and discharge the processing electrode 10 using the dress plate 4. As a discharge power supply serving as a source of the voltage pulse, a discharge power supply used for electric discharge machining (discharge power supply 33 in FIG. 1) or a separately installed power supply may be used.

After the dressing is completed, the amount of protrusion of the processing electrode 10 from the electrode guide 11 is measured by the visual sensor 193 shown in FIG. The amount of protrusion here is
As shown in FIG. 2, the electrode guide 1 in the machining electrode 10
1 is the length of the portion exposed from the lower end. If it is detected in this measurement that the amount of protrusion is less than a predetermined value, the process described in FIGS. Recover the amount.

Although the method of detecting the amount of protrusion of the machining electrode 10 can be performed by a contact detection method using a contact sensor instead of the visual sensor. Also, from the relationship (back data) between the machining time of the electric discharge machining and the electrode consumption of the machining electrode, the amount of protrusion of the machining electrode can be recovered in accordance with the machining time. As described above, the electric discharge machine 1 of the present embodiment
The workpiece 20 can be formed on the workpiece 2 by electric discharge machining using the above.

Next, a description will be given of a comparison between the electric discharge machining using a machining electrode provided with a constant curvature warpage according to the present embodiment and the electric discharge machining using a straight machining electrode according to the prior art as shown in FIG. The workpiece 2 was subjected to electrical discharge machining using the electrical discharge machining apparatus 1 of this example and the machining electrode 10 provided with a warp. The amount of warpage of the processed electrode 10 was 10 μm. Also, as shown in FIG. 7, under the same conditions as in this example, electric discharge machining was performed using a straight machining electrode 90 having no warpage.

As shown in FIG. 2 and FIG.
Each of 0 and 90 is formed of a tungsten wire having a diameter of 70 μm. In this case, the rotation diameter of the processing electrode 10 is 70 μm, and the rotation diameter of the processing electrode 90 is 70 μm. Also,
The rotation speeds of the processing electrodes 10 and 90 are both 3000 rpm. The electric discharge power source 33 in the electric discharge machine 1 to which the machining electrode 10 is attached has a voltage of 110 V and a capacity of 3300 pF.

As shown in FIG. 2 and FIG. 7, when the machining electrodes 10 and 90 rotate,
The diameter of the area described by the zero end. Further, as shown in FIG. 2, the amount of warpage is a distance from the rotation axis of the processing electrode 10 to an end of the processing electrode 10, and is a half of the rotation diameter.

The amount of warpage does not change before and after electric discharge machining. Therefore, the curvature of the machining electrode 10 was kept constant during electric discharge machining. Further, a super hard plate having a thickness of 1.6 mm was used as the work 2, and a machining portion 20 having a hole diameter of 100 μm was subjected to electric discharge machining on the work 2.

As a result of the electric discharge machining, it was found that when the electric discharge machining apparatus 1 and the machining electrode 10 according to this embodiment were used, the machining electrode 10 penetrated the workpiece 2 in about 15 minutes, and the machining portion 20 was obtained. Was. When the obtained processed portion 20 was observed with a microscope or the like, it was found that almost no sludge remained.

However, when the processing electrode 90 as shown in FIG.
Abnormal discharge occurs between the workpiece electrode 0 and the workpiece 2 and the machining electrode 90
Was consumed, the machining electrode 90 did not penetrate the workpiece 2, and the machining portion 20 could not be completed in 15 minutes. When the vicinity of the processing electrode 90 was observed using a microscope or the like, it was found that a large amount of sludge remained in the processing portion 20. As described above, according to the electric discharge machining apparatus 1 of the present example, it was found that sludge was efficiently discharged from the machining section 20 during electric discharge machining, so that machining time could be reduced.

Next, the operation and effect of this embodiment will be described. As shown in FIGS. 2 and 6A, the machining electrode 10 according to the present embodiment is provided with a constant curvature sled, and the machining electrode 10 is configured to be rotatable with respect to the workpiece 2. By rotating the processing electrode 10 with respect to the work 2, the processing liquid 150 around the work 2 is stirred. Therefore, the sludge generated in the processing section 20 is mixed with the stirred processing liquid 1
It is entangled with 50 and quickly discharged out of the processing section 20.

Further, since the processing electrode 10 is provided with a warp, the distance between the rotating shaft of the processing electrode 10 and the processing portion 20 is increased by the amount of the warp as compared with the case where the warp is not provided ( 2 and 7). Accordingly, the distance between the processing electrode 10 and the processing section 20 is increased, and a sufficient sludge discharge path is secured, so that the sludge can be discharged smoothly. In addition, due to the warpage, a flow of the processing liquid 150 is generated in a radial direction from the rotation axis of the processing electrode 10. With this flow, the sludge is more efficiently discharged from the processing section 20.

As the discharge property of the sludge increases, contact between the machining electrode 10 and the work 2 via the sludge hardly occurs, and short circuit and concentrated discharge between the machining electrode 10 and the work 2 hardly occur. Therefore, the processing speed can be increased and the processing accuracy can be improved. Furthermore, since the curvature of the processing electrode according to the present invention has a constant curvature, the diameter of the processed portion can be made uniform, and a processed portion having excellent cylindricity can be obtained.

As described above, according to this embodiment, it is possible to provide an electric discharge machining apparatus capable of improving machining efficiency by efficiently discharging sludge from a machining portion during electric discharge machining.

Further, by continuing the electric discharge machining, the tip of the machining electrode 10 is worn. In order to recover this wear,
In the electric discharge machine 1 of this example, as shown in FIG.
A dress plate 4 configured to be able to dress the tip of the processing electrode 10 is provided, and means for measuring the tip of the processing electrode 10 and means for recovering the amount of protrusion of the processing electrode 10 are provided. For this reason, the machining electrode 1 which does not wear or wear
Electric discharge machining using 0 can always be enabled.
Therefore, stable electric discharge machining can be performed.

In the present embodiment, the processing electrode 10 provided with a constant curvature sled was used. As shown in FIG. 6 (b), an acute-angled machining electrode 10 provided with a constant angle warp.
Can also be used.

Embodiment 2 In this embodiment, as shown in FIGS. 8 and 9, a method for imparting a constant curvature to a machining electrode will be described. The processing electrode having a constant curvature is a processing electrode having a curved warp as shown in FIG. The processing electrode of this example is made of a metal wire 50. The metal wire 50 is wound around the bobbin 51 and plastically deformed. Next, as shown in FIG. 8A, the electrode feeding device 52 drives the electrode feeding guide 53 attached to the electrode guide 11 by the electrode feeding device 52, and through the electrode feeding guide 53 and the electrode guide 11, as shown in FIG. The electrode 10 is protruded from a work (not shown).

In this case, by keeping the amount of protrusion of the processing electrode 10 constant, it is possible to impart a constant curvature to the tip of the processing electrode 10. This is because the metal wire 50 serving as the processing electrode 10 is wound around a bobbin 51 having a constant diameter and is plastically deformed.

In the operation of the electrode feeding device 52 shown in FIG. 8A, the working electrode 10 is sent out when the entire electrode feeding device 52 is lowered while the working electrode 10 is clamped. Then, when it reaches the desired position, the machining electrode 10
Is unclamped, and only the electrode feeder 52 rises. When feeding is restarted, the machining electrode 10 is clamped again. Others are the same as the first embodiment.

In the method described above, it is possible to obtain an effect that it does not take much time to supply the processing electrode provided with the warp. Otherwise, the same effects as in the first embodiment can be obtained.

Next, another method will be described. As shown in FIG. 9 (a), the working electrode of this embodiment stores a wire 60 made of a shape memory alloy 29Cu-Au-45Zn in a cylindrical shape as shown in FIG. Then,
As shown in FIG. 9 (b), the wound wire 60 is unwound and straightened, inserted into the electrode guide 11, and secures a predetermined amount of protrusion to form the processed electrode 10.

As shown in FIG. 9C, this processed electrode 1
0 is immersed in a machining fluid 150 to carry out electric discharge machining by bringing the machining fluid 150 in advance into the transformation temperature 57 ° C.
Warm to above temperature. Therefore, the straightened processing electrode 10 recovers the stored warp by contacting the processing liquid 150, and the processing electrode 1 provided with the constant curvature warpage.
0 electrical discharge machining can be performed. Others are the same as the first embodiment.

In the method described above, the working fluid 1
Since a warp is generated by contact with the workpiece 50, it is possible to supply a processing electrode having a constant curvature with a processing electrode. Otherwise, the same effects as in the first embodiment can be obtained.

Embodiment 3 In this embodiment, as shown in FIG. 10, an electric discharge machining apparatus having an agitator on the outer periphery of an electrode guide will be described. As shown in FIG. 10, the stirring section 12 is provided on the outer periphery 119 of the electrode guide 11.
Is arranged rotatably with respect to the electrode guide 11.

The agitator 12 is driven by power transmitted via a motor (not shown), a pulley and a belt on the motor side, a pulley attached to the agitator 12, and the like.
It is configured to rotate with respect to. Further, as the agitating section 12, various shapes such as those having spiral grooves on the side and bottom surfaces and those having many projections on the bottom surface can be used. Others are the same as the first embodiment.

As the stirring unit 12 according to the present embodiment rotates, a flow is generated in the working fluid around the stirring unit 12 so as to move away from the stirring unit 12 and the processing electrode 10. Sludge naturally coming out of the processing section 20 moves away from the processing electrode 10 on the flow of the processing liquid. In other words, the sludge is blown off by the rotation of the stirring unit 12, and the sludge is prevented from staying between the electrode guide 11 and the work 2.

Accordingly, sludge generated in the processing section 20 is discharged from the processing section 20 by rotation of the processing electrode 10 and the like (see Embodiment 1), and thereafter removed from the vicinity of the processing electrode 10 and the electrode guide 11 by the stirring section 12. Is done. Therefore, by using the electric discharge machining apparatus of this example, it is possible to improve machining efficiency by efficiently discharging sludge. Others are the same as the first embodiment.

[Brief description of the drawings]

FIG. 1 is a configuration explanatory view of an electric discharge machining apparatus according to a first embodiment.

FIG. 2 is an explanatory view of a main part of a machining electrode in the electric discharge machine according to the first embodiment.

FIG. 3 is an explanatory view of a main part of an electrode feed rotation mechanism according to the first embodiment.

FIG. 4 is an explanatory diagram of a process for imparting a constant curvature to the machining electrode in the first embodiment.

FIG. 5 is an explanatory diagram of regeneration of a front end of a worn processing electrode using a dress plate in the first embodiment.

FIGS. 6A and 6B are explanatory diagrams of a processing electrode having a constant curvature and a curved electrode in the first embodiment, and FIGS.

FIG. 7 is an explanatory view of a main part of a straight machined electrode in the first embodiment.

FIG. 8 is an explanatory diagram of a process for imparting a constant curvature to a machining electrode using a bobbin according to the second embodiment.

FIG. 9 is an explanatory diagram of a process for imparting a constant curvature warp to a working electrode made of a shape memory alloy in the second embodiment.

FIG. 10 is an explanatory view of a working electrode provided with a stirring guide according to a third embodiment.

[Explanation of symbols]

 1. . . Electrical discharge machining equipment, 10. . . Processing electrode, 11. . . Electrode guide, 12. . . Stirrer, 2. . . Work, 20. . . Processing part, 33. . . Discharge power supply,

Claims (3)

[Claims] 1. An electric discharge machine comprising a discharge power source for applying a voltage pulse between a processing electrode and a workpiece on which a processing section is to be provided, and having a processing tank filled with a processing liquid for installing the workpiece. An electric discharge machining apparatus characterized in that the machining electrode is provided with a constant curvature or a constant angle, and is configured to be rotatable with respect to the workpiece. 2. The electric discharge machining apparatus according to claim 1, wherein an electrode guide is provided on an outer periphery of the machining electrode. 3. The electric discharge machining apparatus according to claim 2, wherein an agitator configured to be rotatable with respect to the electrode guide is provided on an outer periphery of the electrode guide.