JP2000000723A - Electric discharge machining method and electric discharge machining device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric discharge machining method and an electric discharge machining device heightening sludge discharge performance during electric discharge machining so as to shorten time for a work process and attain efficiency. SOLUTION: When voltage pulse is applied between a machining electrode 10 and a machined workpiece 2 in a working fluid 150 to carry out electric discharge machining, the working fluid 150 is sucked or injected by pressure application into a through hole 20 during electric discharge machining from either one of the machined side 201 and the opposite side 202 to the machined side 201 of the workpiece 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric discharge machining method and an electric discharge machining apparatus for producing small-diameter through holes requiring particularly high precision, such as injection holes of various nozzles and orifices.

[0002]

2. Description of the Related Art A cutting process using an end mill or the like is sometimes used to manufacture a through hole such as an injection hole or an orifice of various nozzles. In the cutting process, a through hole having a fine diameter (a diameter of 500 μm or less) is used. It is very difficult to produce a high precision. For this reason, electric discharge machining may be used instead of cutting to produce a through hole having a fine diameter.

[0003]

However, when the diameter of the through-hole is small, sludge (swarf) generated by machining the through-hole stays between the machining electrode and the through-hole, or is formed in the through-hole. It may adhere. In this case, the electrical connection between the two is conducted, so that the electrical discharge between the machining electrode and the inner wall surface of the through hole is stopped, and it becomes impossible to continue the electrical discharge machining. In this case, the machining electrode must be once taken out of the through-hole and sludge must be removed from the through-hole, which causes an increase in the number of working steps and a long working process.

The present invention has been made in view of the above-mentioned conventional problems, and has been made to enhance the sludge discharge property during electric discharge machining.
An object of the present invention is to provide an electric discharge machining method and an electric discharge machining apparatus which can shorten the working process and increase the efficiency.

[0005]

According to a first aspect of the present invention, when a voltage pulse is applied between a machining electrode and a workpiece to be machined in a machining fluid to perform electrical discharge machining, a machining side on which electrical discharge machining is performed on the workpiece. , Or the machining fluid is sucked into the through hole during electric discharge machining from one of the opposite sides of the machining side,
Alternatively, there is an electric discharge machining method characterized by injecting under pressure.

The operation of the present invention will be described. In the present invention, the machining fluid is injected by applying suction or pressure to the through hole during the electric discharge machining. As a result, the working fluid always flows between the machining electrode and the through-hole, so that sludge can be prevented from staying in this portion or from being welded to the through-hole. Further, the sludge is blown off from the through-hole by injection of the sucked or pressurized working fluid, so that the sludge can be easily discharged out of the through-hole.

For this reason, electric discharge can be continuously generated between the machining electrode and the through hole, and electric discharge machining can be performed efficiently. Therefore, the work process can be shortened, and work efficiency can be improved. Also,
In the present invention, since the through-hole is formed by electric discharge machining, a through-hole having a finer diameter can be accurately produced.

As described above, according to the present invention, it is possible to provide an electric discharge machining method capable of improving the discharge property of sludge during electric discharge machining and shortening the work process and improving efficiency.

Next, as described in the second aspect of the present invention, the work is provided with a prepared hole by pre-machining, and the prepared hole is subjected to electric discharge machining to remove a portion of the cut-off portion to form a through hole. It is preferred to do so.

By the way, in order to shorten the machining time of electric discharge machining, high-speed laser machining, low-cost modeling,
There is a processing method in which a prepared hole is provided in a work by pre-processing using sintering, plastic working, etching, or the like, and the prepared hole is subjected to electrical discharge machining to produce a through hole with required accuracy. .

However, as shown in FIG. 3, which will be described later, a step 209 is formed at the tip of the machining electrode 10, the through hole 20 and the portion where the three contacts with the prepared hole 200 by subjecting the prepared hole 200 to electric discharge machining. Will be done.

Since the vicinity of the step 209 is formed as a bent thin groove, sludge tends to stay very easily.
Sludge may be welded to the through hole 20 and the prepared hole 200 in a short time. For this reason, there has been a problem that the provision of the prepared hole 200 rather increases the processing time. According to the present invention, it is possible to prevent sludge accumulation and welding,
The above-mentioned problem hardly occurs, and the effect of further shortening the processing time can be obtained.

Further, since the pilot hole is provided and the electric discharge machining is performed on the pilot hole, the merit of the pilot hole can be sufficiently enjoyed. The advantage is that, for example, by providing a pilot hole by a high-speed processing method, the entire processing speed can be increased. In addition, the provision of the pilot hole by a low-cost processing method can reduce the overall processing cost.

Next, as in the third aspect of the present invention, it is preferable that the margin volume ratio (= volume of margin portion / volume of through hole) is 0.3 or more.

By the way, the larger the diameter of the prepared hole provided by the pre-machining, the smaller the margin for the electric discharge machining, so that the machining speed can be increased. However, when the diameter of the pilot hole is increased and the margin is reduced, the dischargeable area is reduced, so that discharge concentration is likely to occur.

Here, the discharge concentration means that when the dischargeable area is small, the discharge is likely to be concentrated at one point,
Therefore, since sludge is concentrated in the vicinity,
On the contrary, it is a phenomenon that the efficiency and speed of the processing are reduced, and the processing accuracy is also reduced. Therefore, in the present invention, the machining allowance volume ratio is set within the above range, so that high machining efficiency and high machining accuracy can be obtained. If the margin volume ratio is less than 0.3, the efficiency of machining and the like may be reduced due to the above-described discharge concentration.

Further, it is preferable that the upper limit of the margin volume ratio is 0.8. If the margin volume ratio becomes larger than this, the merit obtained by providing the pilot hole may be reduced.

Next, as in the invention of claim 4, a space is formed on the opposite side of the work side of the work, and it is preferable that the working fluid is injected into the space by applying pressure. When the working fluid is injected into the space, the pressure in the space increases, and a working fluid flows outward from the gap between the working electrode and the through hole. Sludge moves along with the flow of the machining liquid. Therefore, according to this aspect, sludge in the gap between the machining electrode and the through hole can be efficiently discharged. This space can be formed by disposing a jig having an appropriate shape on the opposite side (see Embodiment 1).

Next, as in the fifth aspect of the present invention, a jig for forming a space through which a working fluid can flow in and out is arranged on the opposite side of the work side of the work, and the space formed by the jig is provided. It is preferable that there is a pressure difference between the working fluid in the above and the working fluid in other places. Due to this pressure difference, a flow of the working fluid is generated between the space and other portions. That is, a flow of the machining liquid is generated between the opposite side of the workpiece and the machining side. Since the sludge generated on the processing side of the work can move along with the flow of the processing liquid, the sludge hardly stays in the gap between the processing electrode and the through hole.

Next, a jig for forming a space through which a working fluid can flow in and out is arranged on the opposite side of the work side of the work, as in the invention of claim 6, and the space formed by this jig is provided. It is preferable to supply a working fluid into the inside. By supplying the working fluid to the space, a flow of the working fluid flowing into the space is generated. Since the sludge generated on the processing side of the work can move along with the flow of the processing liquid, the sludge hardly stays in the gap between the processing electrode and the through hole.

Next, a jig for forming a space through which a working fluid can flow in and out is arranged on the opposite side of the work side of the work as described above. It is preferable to suck the working fluid from inside. By sucking the working fluid from the space, a flow of the working fluid flowing out of the space is generated. Since the sludge generated on the processing side of the work can move along with the flow of the processing liquid, the sludge hardly stays in the gap between the processing electrode and the through hole.

Next, as in the invention of claim 8, the processing electrode has a pipe shape provided with an injection passage therein.
It is preferable that the working fluid is supplied or sucked through the injection path. Since the pipe-shaped machining electrode is thin,
When electrode wear occurs due to electric discharge machining, fluctuations in the outer diameter of the machining electrode are small, and variations in machining accuracy due to aging can be reduced.

Next, it is preferable that the working fluid is supplied or sucked through the introduction hole formed in the jig. The diameter of the processing electrode can be made smaller, and a fine through hole can be produced.

Next, it is preferable to perform electric discharge machining using a machining electrode having a taper. As a result, the discharged sludge is diffused in a direction in which the sludge hardly adheres to the processing electrode due to the taper, so that the processing accuracy can be further improved and the processing efficiency can be further improved. The taper can be provided at the tip of the processing electrode (for example, the processing electrode according to the first embodiment).

Next, it is preferable that the work is vibrated. By vibrating the work, a pump effect is generated, and sludge stagnation and sludge welding to the through hole can be more reliably prevented. Further, the working fluid also vibrates due to the vibration of the work, so that the flow velocity between the working electrode and the through hole is increased, and the discharge property of the sludge can be enhanced. In addition, as a method of vibrating the work, for example, a method of applying a high frequency is used.

Next, a twelfth aspect of the present invention is directed to a machining tank in which a machining fluid is stored, a machining electrode for applying a voltage pulse between a workpiece to be machined in the machining fluid, and the work electrode. A jig arranged on the opposite side of the machining electrode to form a space through which the machining fluid can flow in and out of the workpiece, and a working fluid is sucked from a space formed between the jig and the workpiece. And a machining fluid suction means.

As a result, the machining fluid can be sucked from the space, and a flow of the machining fluid flowing out of the space occurs. Since the sludge can move along with the flow of the processing liquid, the discharge property of the sludge from the gap between the processing electrode and the through hole can be improved. For this reason,
Electric discharge can be continuously generated between the machining electrode and the through hole, and electric discharge machining can be performed efficiently. Therefore, the work process can be shortened, and work efficiency can be improved.

As described above, according to the present invention, it is possible to provide an electric discharge machining apparatus capable of improving the discharge property of sludge during electric discharge machining and shortening the work process and improving efficiency.

Next, a thirteenth aspect of the present invention is directed to a machining tank in which a machining fluid is stored, a machining electrode for applying a voltage pulse between a workpiece to be machined in the machining fluid, and the machining electrode. A jig which is arranged on the opposite side of the processing electrode and forms a space through which the processing liquid can flow in and out of the work, and supplies the processing liquid to a space formed between the jig and the work And a machining fluid supply unit.

As a result, the working fluid can be supplied into the space, so that the working fluid flows into the space. Since the sludge can move along with the flow of the processing liquid, the discharge property of the sludge from the gap between the processing electrode and the through hole can be improved. Therefore, electric discharge can be continuously generated between the machining electrode and the through hole, and electric discharge machining can be performed efficiently. Therefore, the work process can be shortened, and work efficiency can be improved. Therefore, it is possible to provide an electric discharge machining apparatus capable of improving the discharge property of sludge during electric discharge machining and shortening the work process and increasing efficiency.

Next, as in the fourteenth aspect of the present invention, the processing electrode has a pipe shape provided with an injection passage therein, and is formed by the jig and the work through the injection passage. It is preferable to supply or suck the processing liquid into the space to be formed. Since the pipe-shaped machining electrode is thin,
When electrode wear occurs due to electric discharge machining, fluctuations in the outer diameter of the machining electrode are small, and variations in machining accuracy due to aging can be reduced.

Next, it is preferable that an introduction hole for supplying or sucking a working liquid is formed in the jig. The diameter of the processing electrode can be made smaller, and a fine through hole can be produced.

Next, as in the sixteenth aspect of the present invention, it is preferable that the inner wall surface of the jig facing the workpiece is a curved surface. This makes it difficult for stagnant portions to be generated in the flow of the working fluid. The stagnation of the working fluid causes the flow of the working fluid to be non-uniform. Since the uneven flow is unstable, the pressure applied to the machining fluid varies. Curved surfaces have the effect of preventing this. Therefore, by providing a curved surface, sludge is evenly discharged, and concentrated discharge is unlikely to occur, so that machining efficiency and machining accuracy are improved.

Next, it is preferable that the space formed by the jig and the work has an axially symmetrical shape with respect to the processing electrode. As a result, since there is no slack in the escape path of the machining fluid (for example, between the machining electrode and the work), average discharge of sludge can be realized. Therefore, concentrated discharge due to sludge is reduced, machining efficiency is improved, and surface accuracy of the through hole is also increased.

Next, as in the eighteenth aspect of the present invention, it is preferable that the processing electrode has a taper. As a result, the discharged sludge is diffused in a direction in which the sludge hardly adheres to the processing electrode due to the taper, so that the processing accuracy can be further improved and the processing efficiency can be further improved. The taper can be provided at the tip of the processing electrode (for example, the processing electrode according to the first embodiment).

Next, it is preferable that a vibration means for vibrating the work is provided. By vibrating the work, a pump effect is generated, and sludge stagnation and sludge welding to the through hole can be more reliably prevented. Further, the working fluid also vibrates due to the vibration of the work, so that the flow velocity between the working electrode and the through hole is increased, and the discharge property of the sludge can be enhanced. As the vibration means, for example, a device for applying a high frequency can be used.

[0037]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 An electric discharge machining method according to an embodiment of the present invention will be described with reference to FIGS. As shown in FIGS. 1 and 2,
In this example, when a voltage pulse is applied between the machining electrode 10 and the work 2 to be machined in the machining fluid 150 to perform the electric discharge machining, the electric discharge machining is performed from the machining side 202 where the electric discharge machining is performed on the work 2. Working fluid 150 for through hole 20 of
Is injected under pressure to perform electric discharge machining.

First, the electric discharge machine 1 used in this embodiment will be described. As shown in FIG.
Is attached to an electrode feed head 13 via an electrode guide 11. A machining tank 15 filled with a machining liquid 150 is disposed below the machining electrode 10, and electric discharge machining is performed in the machining tank 15.

The electrode feed head 13 is mounted on an NC shaft 14, and the feed amount of the machining electrode 10 by the NC shaft 14 is controlled by an NC shaft controller 31. Reference numeral 33
Is a discharge power supply for applying a voltage pulse to the machining electrode 10 and the work 2. The application of the voltage pulse to the work 2 is performed via the processing tank 15 and a jig 28 described later.

As shown in FIG. 1, a work 2 to be processed and a jig 28 for supporting the work 2 are arranged in the processing tank 15, and a space is provided between the jig 28 and the work 2. 289 are formed. Further, the processing electrode 10 has an injection path 109 formed on the axis, and the processing liquid 150 is configured to be injected into the space 289 from this. A taper 100 is provided at the tip of the processing electrode 10 (see FIG. 3).

As shown in FIG. 2, a dress plate 4 for restoring the shape of the machining electrode 10 consumed by electric discharge machining is disposed near the jig 28. Reference numeral 16 denotes a working fluid pump for flowing the working fluid 150 from the working fluid tank 151 to the working tank 15.

The electric discharge machining method according to this embodiment will be described. First, a prepared hole 200 is formed by cutting at a position where the through hole 20 of the work 2 is to be provided. Next, FIG.
As shown in FIG.
To place. Subsequently, the processing liquid 1 is stored in the processing liquid tank 151.
50 is supplied into the processing tank 15 using the processing liquid pump 16. At this time, the working fluid 150
Flows, and the space 289 is filled.

Next, the electrode feed head 13 is operated, and the tip of the machining electrode 10 is placed in the prepared hole 200 of the work 2.
Next, the discharge power supply 33 is operated, a voltage pulse is applied between the machining electrode 10 and the workpiece 2, and electric discharge machining is performed as shown in FIG.

During this electric discharge machining, as shown in FIG. 1B, the machining fluid pump 16 is driven, and the machining fluid 150 is pressurized and the arrow A is directed from the injection path 109 toward the space 289 while pressurizing the machining fluid 150.
Inject as shown in As a result, the pressure in the space 289 increases, and a flow of the machining liquid 150 is generated from the gap between the machining electrode 10 and the through hole 20 as shown by the arrow B. Along with this flow, sludge generated by electric discharge machining is discharged from the machining side 202 of the work 2 in the direction shown by the arrow B. Thus, the pilot hole 200 becomes the through hole 20 as shown in FIG.

After the completion of electric discharge machining, the electrode feed head 13 is operated, and the machining electrode 10 is pulled out of the through hole 20.
It is retracted above the work 2. Thereafter, the workpiece 2 having the through hole 20 is replaced with an unprocessed workpiece, and the electric discharge machining is further continued.

The machining electrode 10 is gradually consumed by electric discharge machining. Therefore, the dressing process is performed by applying the tip of the processing electrode 10 to the dressing plate 4 disposed adjacent to the workpiece 2 every time a predetermined time elapses, and the consumed processing electrode 10 is reproduced. Note that the dressing is to apply a voltage pulse between the processing electrode 10 and the dress plate 4 and subject the processing electrode 10 to electrical discharge machining using the dress plate 4.

Next, the operation of the present embodiment will be described. In this embodiment, a machining fluid 150 is injected into the through-hole 20 during the electric discharge machining. Thereby, the processing electrode 1
0 and the through-hole 20 are always in a state in which the machining liquid 150 flows, and sludge stays in this portion or the through-hole 2
It is possible to prevent the sludge from welding to zero.

Further, in this embodiment, the working fluid 15
0 is injected, the pressure in the space 289 increases, and the through-hole 20 serving as the only outlet of the space 289 and the machining electrode 1
A flow toward the gap with zero occurs. Sludge is easily discharged out of the through-hole 20 along this flow.

Therefore, the electric discharge can be continuously generated between the machining electrode 10 and the through hole 20, and the electric discharge machining can be performed efficiently. Therefore, the work process can be shortened, and work efficiency can be improved.

In this embodiment, a preliminary hole 200 is provided in the work 2 by pre-machining, and as shown in FIG. 3, the preliminary hole 200 is subjected to electric discharge machining to obtain the required accuracy and size. A held through hole 20 is produced.

In this case, as shown in FIG.
Since a step 209 is formed at the point where the three parts of the front end portion 0 and the through hole 20 and the prepared hole 200 contact each other, the flow rate of the machining liquid 150 is likely to be small in the vicinity thereof, and sludge tends to stay there.

According to this embodiment, as described above, the space 28
9 flows toward the gap between the through-hole 20 and the processing electrode 10, the flow rate of the processing liquid 150 in the vicinity of the step 209 is unlikely to decrease, and the sludge remains and welds in the step 209. Can be prevented.
In addition, in this example, since the through hole 20 is processed by electric discharge machining, the through hole 20 having a finer diameter can be manufactured with high accuracy.

As described above, according to this embodiment, it is possible to provide an electric discharge machining method capable of improving the discharge property of sludge during electric discharge machining and shortening the working process and improving efficiency.

Further, the electric discharge machining method according to the present embodiment can be used for machining a fuel injection port of an injector nozzle as described below. The injector nozzle 8 is shown in FIG.
As shown in FIG. 5, a fuel supply path 5 for supplying fuel is provided.
0, a fixed core 5, a housing 40 surrounding the fixed core 5, and a valve body 6 provided at a distal end of the housing 40 and having an ejection port 60 for ejecting the fuel.

The injector nozzle 8 has a needle valve 65 provided in the valve body 6 so as to be capable of moving forward and backward so as to open and close the jet port 60, and is connected to the needle valve 65 and has an electromagnetic force in the housing 4. And a movable core 7 provided so as to be able to advance and retreat.

As shown in FIG. 5, the state where the fuel 80 is supplied into the injector nozzle 8 and the first shaft portion 652 of the needle valve 65 is pressed against the contact portion 651 by the spring 82 is a stationary state. . Connector 8
By supplying power from an external power supply to the electromagnetic coil 46 through the needle 1, the needle valve 65 is lifted and the ejection port 60 is
From the fuel 80 is sprayed in a mist. When the current of the electromagnetic coil 46 is stopped, the needle valve 65 closes the injection port 60 and suppresses fuel injection.

Embodiment 2 In the electric discharge machining method of this embodiment, as shown in FIG. 6, a machining fluid 150 is applied to the through hole 20 during electric discharge machining from the side 201 opposite to the machining side 202 of the work 2 by applying pressure. Inject. In this example, the same electric discharge machining apparatus as that in the first embodiment is used.

As shown in FIG. 1, a work 2 to be machined and a jig 29 for supporting the work 2 are arranged in the work tank 15. A working fluid circulation hole 290 is provided at the bottom of the jig 29, and a machining fluid 150 introduced from an introduction hole 160 provided in the processing tank 15 is introduced into the machining fluid circulation hole 290. The state is filled with the processing liquid 150.

The electric discharge machining according to this embodiment is performed as follows. First, a prepared hole is formed by cutting at a position where the through hole 20 of the work 2 is to be provided. Next, as shown in FIG. 6, the work 2 is placed in the processing tank 15 using the jig 29. Subsequently, 150 is transferred from the processing liquid tank to the processing tank 15.
And the inside of the jig 29.

Next, the electrode feed head 13 is operated, and the tip of the machining electrode 10 is arranged in the prepared hole of the work 2. next,
The discharge power supply 33 is operated to apply a voltage pulse between the machining electrode 10 and the work 2, and the above-described FIGS. 1B and 1C are used.
The electric discharge machining is performed as shown in FIG.

During this electric discharge machining, the machining fluid pump 1
6 and pressurizing the working fluid 150 while introducing the introduction holes 160,
Injection is made from the machining fluid flow hole 290 toward the through hole 20 as shown by the arrow C. Thereby, the sludge generated by the electric discharge machining is discharged from the machining side of the work 2 in the direction shown by the arrow B.

After the electric discharge machining is completed, the electrode feed head 13 is operated, and the machining electrode 10 is pulled out of the through hole 20.
It is retracted above the work 2. Thereafter, the workpiece 2 having the through hole 20 is replaced with an unprocessed workpiece, and the electric discharge machining is further continued. Others are the same as the first embodiment.

The processing electrode 10 used in the manufacturing method of this embodiment has a low manufacturing cost. For this reason, the cost of the electric discharge machine can be reduced. Others are the first embodiment.
It has the same function and effect as described above.

Embodiment 3 As shown in FIG. 7, in this embodiment, as in Embodiment 2, a machining fluid 150 is injected from the opposite side 201 of the work 2 into the through hole 20 during electric discharge machining by applying pressure. Then, electrical discharge machining is performed. A jig 29 for supporting the work 2 is disposed on the opposite side 201 of the work 2, and a space 289 is formed between the jig 29 and the work 2. Further, a working fluid flow hole 290 is provided so as to conduct between the space 289 and the introduction hole 160 provided in the processing tank 15. And
The inner wall surface of the space 289 has a curved surface. Others are the same as the second embodiment.

In the manufacturing method of this embodiment, since the inner wall surface of the space 289 has a curved surface, the pressure of the working fluid injected into the space is made uniform. For this reason, since there is no slack in the escape path of the machining liquid (in this case, between the machining electrode and the workpiece), an average sludge discharge can be realized. As a result, concentrated discharge due to sludge is reduced, so that machining efficiency is improved and surface accuracy of the through hole is also increased. Moreover, the manufacturing cost of the used processing electrode 10 is low. For this reason,
The cost of the electric discharge machine can be reduced. Others have the same operation and effects as the first embodiment.

Fourth Embodiment In this embodiment, as shown in FIG. 8, the machining fluid 150 is sucked from the opposite side 201 of the work 2 into the through hole 20 during the electric discharge machining to perform the electric discharge machining. Opposite side 2 of work 2
A jig 29 for supporting the jig 29 is disposed in 01, and a space 289 is formed between the jig 29 and the work 2. Further, a working fluid flow hole 290 is provided so as to conduct between the space 289 and the introduction hole 160 provided in the processing tank 15. The introduction hole 160 is connected to a pump (not shown). Others are the same as the first embodiment.

In the manufacturing method of this embodiment, the working fluid is sucked from the introduction hole 160 by the pump. For this reason, the space 289 and the machining fluid circulation hole 2 extend from the gap between the through hole 20 and the machining electrode 10.
Since the flow of the working fluid 150 toward the inlet hole 90 and the introduction hole 160 occurs, sludge accumulation and welding can be prevented. Others have the same operation and effects as the first embodiment.

Fifth Embodiment As shown in FIGS. 9 to 12, in this embodiment, as in the first embodiment, a machining fluid is injected from the machining side into a through hole during electric discharge machining by applying pressure, and electric discharge is performed. Processing is performed. FIG.
As shown in FIG.
00 is provided, the electric discharge machining is performed on the prepared hole 200, and the cut-out portion 209 is removed to form a through hole.

FIG. 9 shows the electric discharge machining apparatus 1 used in this embodiment. The processing electrode 10 is mounted on an electrode feed head 13 via an electrode guide 11. A machining tank 15 filled with a machining liquid 150 is disposed below the machining electrode 10, and electric discharge machining is performed in the machining tank 15. Processing tank 1
Numeral 5 is configured to be movable in the front, rear, left, and right directions, as indicated by arrows in FIG. The electrode feed head 13 is the NC axis 1
The feed amount of the machining electrode 10 by the NC shaft 14 is controlled by an NC shaft control device 31.

Reference numeral 33 denotes the machining electrode 10 and the work 2.
This is a discharge power supply for applying a voltage pulse to. In addition,
The application of the voltage pulse to the work 2 is performed via the processing tank 15 and a jig 29 described later. Further, the electric discharge machine 1 of the present embodiment is provided with a position measuring device 18 for measuring the hole diameter, position, and the like of the prepared hole 200 and the through hole 20.

The working method of this embodiment will be described. The work 2 provided with the prepared hole 20 by laser processing is set on a jig 28 in the processing tank 15 of the electric discharge machine 1. Next, the processing tank 15 is moved below the position measuring device 18, and the position and diameter of the prepared hole 200 are measured using the position measuring device 18.
Next, the processing tank 15 is moved below the processing electrode 10,
The NC axis controller 31 and the like are controlled based on the result of the measurement, and the pilot hole 200 is subjected to electric discharge machining to form the through hole 20. Others are the same as the first embodiment.

Next, using the electric discharge machining apparatus 1 according to the present embodiment, a machining efficiency was tested in a case where the stock removal volume ratio was appropriately changed. In this test, the machining electrode 10 of the electric discharge machine 1 was used.
The diameters are 100 μm, 300 μm, and 500 μm, and as shown in FIG.
Through holes of 00 μm and 500 μm were formed. The diameter R ₀ of the pilot hole used was of an appropriate size such that the margin volume ratio varied from 0.05 to 1. Also, D = 1mm
Met. The applied voltage to the processing electrode is 100 V
Met.

The results of the test under the above conditions are shown in the diagram of FIG. Note that the processing efficiency in the figure is the speed of the processing amount calculated from the total time required for processing and the removal allowance volume removed by processing. According to the figure, regardless of the value of the diameter of the machining electrode 10, the machining efficiency is excellent when the margin volume ratio is 0.3 or more. It can be seen that in some cases a very good processing efficiency is obtained.

The electric discharge machine according to this embodiment is
As shown in FIG. 11, an electric discharge machining apparatus provided with a laser machining apparatus 19 can be used. The laser processing device 19 includes a laser oscillator 191, a reflection mirror 192 for reflecting and condensing a laser 190 emitted from the laser oscillator 191, and a condenser lens 193.

In this apparatus, the work 2 is arranged on a jig 29 in an empty processing tank 15, and the work 2 is moved together with the processing tank below the laser processing apparatus 19 to perform laser processing of the prepared hole 200. Thereafter, the processing tank 1 is placed below the processing electrode 10.
5 and the work 2 is moved, and the processing liquid 150 is transferred to the processing tank 15.
Supply inside. After that, the through hole 20 is formed in the work 2 as in the first embodiment.

By using such an electric discharge machine 1, it is possible to reduce the work transfer time. Also,
Information on the prepared hole 200 machined from the laser machining apparatus 19 is used to control the machining electrode 10 in the electric discharge machine 1 (N
(C-axis control device 31 etc.), and both can be operated in cooperation, so that the time required for measurement of pilot hole 200 and the like can be reduced, and efficient electric discharge machining can be realized.

Embodiment 6 Next, as shown in FIG. 13 to FIG. 16, a case where a workpiece is vibrated to perform electric discharge machining will be described. The apparatus used in this example is the above-described electric discharge machining apparatus according to FIG. 1, in which the vibration device 3 according to FIG. As shown in FIG. 13A, the vibration device 3 incorporates piezoelectric elements 31 and 32 and has vibration axes 33 and 34. The surface 331 of the vibration shaft 33 has a concave portion 35 and the surface 332 has a concave portion 36. These recesses 35 and 36 are communicated with each other by a passage 37 inside as shown in FIG.

In the following test, as shown in FIG.
The vibrating device is arranged in the electric discharge machine so that 6 faces the machining electrode. Then, as shown by a broken line in FIG. As shown in FIG. 14 (b), when it is desired to apply horizontal circular vibration to the work 2, the vibration device is arranged in the electric discharge machine so that the concave portion 35 faces the machining electrode. Then, as shown by a solid line in FIG.

The working efficiency when the work 2 was vibrated by using such a vibration device 3 was tested as follows. Since this vibration device 3 has two shafts that can vibrate,
As shown in FIG. 14A, vertical vibration can be imparted by installing in a processing tank and performing uniaxial vibration. 14 (b), it can be installed in a processing tank,
By adjusting the amplitude and phase of the shaft, elliptical vibration and circular vibration can be applied to the work. PZT (PbZr)
A solid solution of O ₃ and PbTiO ₃ ) is an element that expands and contracts when voltage is turned on and off. Therefore, by applying a sine wave frequency, vibrations required for the following tests can be obtained.

As shown in FIG. 14A, when vertical vibration is applied to the work 2, the work 2 is arranged in the concave portion 36 provided in the surface 332 of the vibration shaft 33, It is installed in the electric discharge machine so as to face the machining electrode. Then, the working fluid is sucked from the recess 35 side.

As shown in FIG. 14B, when a horizontal circular vibration is applied to the work 2, the vibrating device 3 is placed in the recess 35 provided on the surface 331 of the vibration shaft 33.
Is disposed on the electric discharge machine so that this surface faces the machining electrode. Then, the working fluid is sucked from the concave portion 36 side.

When horizontal vibration was applied, the processing efficiency was measured when the frequency was constant and the amplitude was appropriately changed, and is shown in FIG. 15 (a). In addition, the processing efficiency when the frequency was appropriately changed while the amplitude was constant was measured, and is shown in FIG. When horizontal vibration is applied, the machining efficiency is measured when the oscillation radius is appropriately changed while the frequency is constant.
6 (a). In addition, the machining efficiency when the frequency was appropriately changed while the swing radius was constant was measured, and is shown in FIG. 16 (b). The measurement of the processing efficiency is the same as in the fifth embodiment.

From these results, it was found that the machining efficiency can be improved by giving an appropriate range of vibration. In the case of the through hole 20 according to this example, the efficiency is highest when the amplitude is 3 μm and the frequency is about 1000 Hz in the case of vertical vibration. In the case of horizontal vibration, the oscillation radius is 5 μm and the frequency is 4
00 Hz.

When the machining efficiency was measured while applying a vertical vibration and changing the frequency appropriately with a constant amplitude, the machining efficiency was measured when the machining electrode was rotated.
It was described in (b). From the figure, it was found that if the machining electrode was rotated, machining efficiency was improved even when no vibration was applied. In addition, it was found that high machining efficiency could be obtained if appropriate vibrations were applied regardless of the rotation of the machining electrode.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an electric discharge machining method according to a first embodiment.

FIG. 2 is an explanatory diagram of an electric discharge machine according to the first embodiment.

FIG. 3 is an explanatory view of electric discharge machining for a pilot hole according to the first embodiment.

FIG. 4 is an explanatory diagram of an injector nozzle according to the first embodiment.

FIG. 5 is an explanatory view of an ejection port of the injector nozzle of FIG. 4 according to the first embodiment.

FIG. 6 is an explanatory view of an electric discharge machining method according to Embodiment 2 in which a machining fluid is injected from the opposite side.

FIG. 7 is an explanatory view of another electric discharge machining method according to Embodiment 3 in which a machining fluid is injected from the opposite side.

FIG. 8 is an explanatory view of an electric discharge machining method according to Embodiment 4 in which a machining fluid is sucked from the opposite side.

FIG. 9 is an explanatory view of an electric discharge machine according to a fifth embodiment.

FIG. 10 is an explanatory diagram showing dimensions of a pilot hole and a through hole according to the fifth embodiment.

FIG. 11 is a diagram showing a relationship between a diameter of a processing electrode, a machining allowance volume ratio, and processing efficiency according to the fifth embodiment.

FIG. 12 is an explanatory view of an electric discharge machining apparatus provided with a laser machining apparatus according to a fifth embodiment.

FIGS. 13A and 13B are explanatory diagrams of a vibration device according to a sixth embodiment, and FIGS.

FIG. 14 is a diagram illustrating a work according to the sixth embodiment.
(A) Explanatory diagram when vertical vibration is applied by a vibration device,
(B) Explanatory drawing at the time of giving a horizontal circular vibration.

FIG. 15 is a diagram showing a processing efficiency when a vertical vibration is applied according to the sixth embodiment.

FIG. 16 is a diagram showing processing efficiency when a horizontal circular vibration is applied according to the sixth embodiment.

[Explanation of symbols]

 1. . . Electrical discharge machining equipment, 10. . . Processing electrode, 150. . . Working fluid, 2. . . Work, 201. . . Opposite side, 202. . . Processing side,

Claims (19)

[Claims] In a machining fluid, a voltage pulse is applied between a machining electrode and a workpiece to be machined to perform an electrical discharge machining, and a machining side on which the electrical discharge machining is performed on the workpiece or a side opposite to the machining side. A machining fluid is sucked into a through hole during electrical discharge machining from one of the above, or a pressure is applied by injection. 2. A workpiece according to claim 1, wherein said work is provided with a pilot hole formed by pre-machining, said electric discharge machining is performed on said pilot hole, and a margin is removed to form a through hole. Electrical discharge machining method. 3. The electric discharge machining method according to claim 2, wherein a volume ratio (= volume of the margin portion / volume of the through hole) is 0.3 or more. 4. The method according to claim 1, wherein:
An electric discharge machining method, characterized in that a space is formed on the opposite side of the machining side of the work, and a working fluid is injected under pressure into the space. 5. The method according to claim 1, wherein:
A jig that forms a space through which the machining fluid can flow in and out is placed on the opposite side of the workpiece from the machining side, and between the machining fluid in the space formed by this jig and the machining fluid in other places. An electric discharge machining method characterized by having a pressure difference. 6. The method according to claim 1, wherein:
An electric discharge machining method comprising: disposing a jig that forms a space through which a machining fluid can flow in and out, and supplying a machining fluid into a space formed by the jig, on a side opposite to a machining side of the work. . 7. The method according to claim 1, wherein:
An electric discharge machining method comprising: disposing a jig that forms a space through which a machining fluid can flow in and out of the work, and sucking the machining fluid from the space formed by the jig. . 8. The method according to claim 1, wherein:
The electric discharge machining method, wherein the machining electrode has a pipe shape provided with an injection passage therein, and a machining liquid is supplied or sucked through the injection passage. 9. The method according to claim 5, wherein
An electric discharge machining method, wherein a machining fluid is supplied or sucked through an introduction hole formed in the jig. 10. An electric discharge machining method according to claim 1, wherein electric discharge machining is performed using a machining electrode having a taper. 11. The electric discharge machining method according to claim 1, wherein the work is vibrated. 12. A machining tank for storing a machining fluid, a machining electrode for applying a voltage pulse between a workpiece to be machined in the machining fluid, and a machining electrode disposed on the opposite side of the machining electrode with the workpiece interposed therebetween. A jig for forming a space through which a machining fluid can flow in and out between the workpiece and the machining fluid suction means for sucking a machining fluid from a space formed between the jig and the workpiece. An electric discharge machine characterized by the above-mentioned. 13. A processing electrode for applying a voltage pulse between a processing tank in which a processing liquid is stored, a work to be processed in the processing liquid, and an opposite side of the processing electrode with the work interposed therebetween. A jig for forming a space through which the machining fluid can flow in and out between the work and the work, and a machining fluid supply means for supplying the machining fluid to a space formed between the jig and the work. An electric discharge machine characterized by the above-mentioned. 14. The space according to claim 12 or 13, wherein the processing electrode has a pipe shape having an injection path provided therein, and a space formed by the jig and the work via the injection path. An electric discharge machine characterized by supplying or sucking a machining fluid to a workpiece. 15. An electric discharge machining apparatus according to claim 12, wherein an introduction hole for supplying or sucking a machining fluid is formed in said jig. 16. The electric discharge machine according to claim 12, wherein an inner wall surface of the jig facing the workpiece is a curved surface. 17. The method according to claim 12, wherein a space formed by the jig and the work has a shape that is axially symmetric with respect to the machining electrode. Electric discharge machine. 18. An electric discharge machining apparatus according to claim 12, wherein said machining electrode has a taper. 19. An electric discharge machining apparatus according to claim 12, further comprising a vibration means for vibrating said work.