JPH0386429A - Electrode for electric discharge machining - Google Patents

Abstract

PURPOSE:To enable the electric discharge machining of a very small hole for an outer peripheral wall with simplicity and coaxial accuracy by disposing a very thin rod electrode coaxially in the center of a pipe shape electrode of conductive material. CONSTITUTION:Using a very thin rod electrode 7 and a pipe shape electrode 6 which are coaxially disposed, electric discharge machining is given in the same place to a very small hole 15 on a process raw material 10, a round outer peripheral wall 16 or the outer peripheral wall in a round periphery recess part. This enables the electric discharge machining of the very small hole 15 for the outer peripheral all 16 with coaxial accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is particularly applicable to inkjet printer nozzles, electron gun apertures, fluid nozzles, etc., particularly in the case of a circular peripheral wall of a processed workpiece or a circular peripheral recessed part concentrically with the peripheral wall. This invention relates to an electrode for electrical discharge machining used for electrical discharge machining of micro holes with a diameter of 100 microns or less that require.

Conventional technology Conventionally, micro-drilling, laser machining, electron beam machining, electric discharge machining, chemical etching, etc. have been used to process micro-holes. There were various issues such as workability and reproducibility.

However, recently, special machines for micro-electrical discharge machining have been put into practical use with miniaturized discharge energy per single shot, and electrical discharge machining of micro-holes and shafts with diameters of several tens of microns has become possible (National Technical report
Vol, 31 N.

5 pp105).

Hereinafter, a conventional microhole electrical discharge machining electrode and a microhole electrical discharge machining method using this electrode will be described with reference to FIG. In FIG. 6, reference numeral 101 is an electrode for micro-hole electric discharge machining, and the electrode portion at the tip is formed into a rod shape having an outer diameter corresponding to the diameter of the machined hole. 102 is a disk-shaped workpiece, 103 is a V-shaped positioning jig that holds the workpiece 102 in a positioned state, and 104 is an electrode 1.
This is a discharge circuit that generates a discharge between 01 and the workpiece 102, and includes a power supply 105, a capacitor 106, and a resistor 10.
It consists of 7.

Then, without trenching, the processed workpiece 102 is treated with eddying fluid (not shown).
and held in a predetermined position by the positioning jig 103. Next, the power source 105 is activated, and the electrode 101 is rotated by a rotating means and a driving means (both not shown) and fed in the two directions of the arrows, thereby electrical discharge machining a fine hole in the workpiece 102 in a manner similar to the electrode 101. be able to.

Problems to be Solved by the Invention In order to electrical discharge machine a microhole that requires concentricity with the circular outer peripheral wall 108 of the workpiece 102 using the conventional microhole electrical discharge machining method as described above, trial machining is performed. , it is necessary to repeatedly correct the position of the workpiece 102 several times to achieve a predetermined accuracy. However, in such trial machining, there is waste due to defective workpieces 102, and the concentricity of the micro holes varies due to variations in the external dimensions of the workpieces 102, making it difficult to ensure accuracy. There was an issue.

The present invention solves the conventional problems as described above.
The fine rod-shaped electrode part at the center and the pipe-shaped electrode part on the outer periphery are arranged concentrically to form a micro hole, and the circular outer wall or the outer peripheral wall of the circular outer recessed part is electrically discharged at the same position, making it concentric to the outer peripheral wall. It is an object of the present invention to provide an electrode for electrical discharge machining that can easily machine fine holes with high precision.

Means for Solving the Problems In order to achieve the above object, the present invention includes a pipe-like electrode portion and a fine rod-like electrode portion made of a conductive material, and the fine rod-like electrode portion is placed at the center of the pipe-like electrode portion. They are arranged concentrically.

Moreover, the pipe-shaped electrode part and the fine rod-shaped electrode part are combined so that they can be individually slid in the axial direction.

The pipe-shaped electrode part is formed of a pipe-shaped member, and this pipe-shaped member has a small diameter guide hole on the inside rear side of the pipe-shaped electrode part, and the small diameter guide hole is inserted into the rear side of the fine rod-shaped electrode part. or the pipe-shaped electrode part is formed of a pipe-shaped member, and a guide is fixed to the rear inner side of the pipe-shaped electrode part that is buttoned to the pipe-shaped member, and The rear side portion of the fine rod-shaped electrode portion can be slidably supported in the guide hole.

Therefore, according to the present invention, a fine rod-like electrode part and a pipe-like electrode part arranged concentrically form a fine hole in a processed material and the circular outer peripheral wall or the outer peripheral wall of a circular peripheral recessed part at the same position. Since the electric discharge machining can be performed using the same method, it is possible to perform the electric discharge machining of minute holes with good concentricity accuracy on the outer peripheral wall.

EXAMPLES Hereinafter, examples of the present invention will be described with reference to the drawings.

Without further ado, a first embodiment of the present invention will be described.

FIGS. 1(a) and (b) show an electric discharge machining electrode according to a first embodiment of the present invention, FIG. 1 (at is a cross-sectional view of the tip, and FIG. FIG.

As shown in FIG. 1(a) and (bl), the electrode 1 for electrical discharge machining
is constructed by combining a pipe-like member 2 made of a conductive material and a fine rod-like member 3. The pipe-like member 2 has a large-diameter hole 4 formed at its tip, and a small-diameter guide hole 5 formed at the center of the rear inside.○The rod-like member 3 is inserted into this guide hole 5.
is inserted in a slidable and rotatable manner, and a pipe-shaped (ring-shaped) electrode part 6 and a fine rod-shaped electrode part 7 are formed at the tip. The electrodes 7 are arranged concentrically and supported so as to be able to independently slide relative to each other in the axial direction. The diameter of the hole 4 of the pipe-shaped electrode part 6 and the outer diameter of the fine rod-shaped electrode part 7 are both equal to the workpiece 10.
The micro holes 15 concentric with the circular outer peripheral wall 16 of a (Fig. 4(a)
It is formed to match the completed shape and dimensions of t and (see bl). The pipe-like member 2 and the fine rod-like member 3, that is, the pipe-like electrode part 6 and the fine rod-like electrode part 7 of this electrode machine for electric discharge machining are rotated by the rotating means 8 and vertically (direction of arrow Z) by the driving means 9. (see Fig. 2 (al)).

The electric discharge machining operation using the electrode 1 for electric discharge machining having the above structure will be explained with reference to the cross-sectional diagram for explaining the electric discharge machining operation shown in FIG. 2 (at to dl).

First, the processing material 10 is immersed in an insulating liquid (not shown),
As shown in FIG. 2 (al), a discharge rotation 14, which consists of a power source 11, a capacitor 12, and a resistor 13 and supplies discharge energy, is connected to the pipe-shaped electrode part 6, the fine rod-shaped electrode part 7, and the workpiece 10. Then, the power source 11 is put into operation, the pipe-like electrode section 6 and the fine rod-like electrode section 7 are rotated by the rotating means 8, and the fine rod-like electrode section is rotated as shown in FIGS. 7 is sent in the direction of arrow Z by the drive control means 9, and electric discharge machining of the fine hole 15 is performed on the workpiece 10. When the electric discharge machining of the fine hole 15 is completed, as shown in FIG. The electrode part 6 is fed in the direction of arrow Z by the drive control means 9, and the workpiece 1 is
0, the circular outer peripheral wall 16 is subjected to electric discharge machining.

As shown in FIG. 4 (at, (bl), the above operation results in
It is possible to complete electrical discharge machining of a disk-shaped workpiece 10a having a microhole 15 concentrically with the center of the circular outer peripheral wall 16.

In this way, since the fine hole 15 and the circular outer peripheral wall 6 are electrically discharged at the same position by the fine rod-shaped electrode part 7 and the pipe-shaped electrode part 6 that are coaxially centered, good concentricity accuracy with respect to the circular outer peripheral wall 16 can be achieved. Electric discharge machining of the micro holes 15 can be easily performed.

Next, a second embodiment of the present invention will be described.

FIG. 3 is a cross-sectional view of the tip of an electric discharge machining electrode according to a second embodiment of the present invention.

In the third embodiment, as shown in FIG. 3, the inner diameter of the pipe-shaped member 2 is uniform over almost the entire length, and a guide 17 is inserted and fixed inside the rear inside of the pipe-shaped electrode part 6. A fine rod-shaped member 3 is slidably supported in a guide hole 18 at the center of this guide 17. The guide 17 may be made of a conductive material such as metal or a non-conductive material such as ceramic, but it is necessary to use a material that has good lubricity with the micro rod-shaped member 3. The other configurations are the same as those of the first embodiment.

In this embodiment as well, as shown in FIGS. The electrode portion 6 allows concentric, accurate, and easy electrical discharge machining.

Next, FIGS. 5(a) and 5(a) show other processing examples according to the present invention.
This will be explained with reference to bl.

As shown in FIG. 5(a) and (bl), the circular recessed part 19
In the case of a workpiece 10b in which a microhole 15 is machined in the center of
5 is performed, and the pipe-shaped electrode part 6 is shown in FIG. 2 (c).
By controlling the two directions applied to l, (dl) at predetermined positions, electric discharge machining of the annular recessed part 19 is performed,
It is possible to perform electric discharge machining to form a fine hole 15 with good concentric accuracy on the outer peripheral wall 20.21 of the annular recessed portion 19.

Of course, in the processing example shown in FIGS. 5(at and fbl), it is necessary to reduce the inner diameter of the pipe-like electrode part 6 in the third embodiment of the first and second embodiments to form the pipe-like electrode part 6 thickly. There is.

However, in each of the above embodiments, the fine hole 15 is first electrically discharged using the fine rod-shaped electrode section 7, and then the outer peripheral wall 16 or 20, 21 is electrically discharged using the pipe-shaped electrode section 6. Alternatively, the fine rod-shaped electrode part 7 and the pipe-shaped electrode part 6 may be fed in two directions simultaneously to carry out the processing. The housing, rod-shaped microelectrode section 7 and pipe-shaped microelectrode section 6 may be integrated.

Effects of the Invention In short, according to the present invention, a fine rod-like electrode part and a pipe-like electrode part arranged concentrically form a fine hole and a circular outer peripheral wall in a processed material, or the outer peripheral wall of a circular peripheral recessed part at the same position. Since it is possible to perform electric discharge machining using the same method, it is possible to easily perform electric discharge machining to form fine holes with good concentricity on the outer peripheral wall.

[Brief explanation of drawings]

Figure 1 (at, (bl) shows an electric discharge machining electrode according to the first embodiment of the present invention, the same figure (al is a sectional view of the tip, the figure (bl is a perspective view of the tip, FIG. 2 (at or dl is a sectional view for explaining the electric discharge machining operation according to the above embodiment,
FIG. 3 is a sectional view of the tip of the electrode for electrical discharge machining according to the second embodiment of the present invention, and FIG. Figure (at
is a perspective view, the same figure (bl is a cross-sectional view, Fig. 5 (a), (b)
shows another example of machining using the electrode for electric discharge machining of the present invention,
The same figure (at is a perspective view, the same figure (bl is a sectional view.
The figure is a perspective view showing a conventional micro-hole electric discharge machining electrode and machining method. DESCRIPTION OF SYMBOLS 1... Electrode for electric discharge machining, 2... Pipe-shaped member, 3...
... Fine rod-shaped member, 5... Guide shape, 6... Pipe-shaped electrode part, 7... Fine rod-shaped electrode part, 10... Processed material, 10a. 10b processed work, 15... minute hole, 16... outer peripheral wall, 7... guide, 8... guide hole, 9... recessed part, 20° 1... outer peripheral wall.

Claims (4)

[Claims] (1) An electrode for electric discharge machining, comprising a pipe-shaped electrode part and a fine rod-shaped electrode part made of a conductive material, and the fine rod-shaped electrode part is arranged concentrically at the center of the pipe-shaped electrode part. (2) The electric discharge machining electrode according to claim 1, wherein the pipe-shaped electrode part and the fine rod-shaped electrode part are combined so as to be able to individually slide in the axial direction. (3) The pipe-shaped electrode part is formed of a pipe-shaped member,
The pipe-like member has a small-diameter guide hole on the inner rear side of the pipe-like electrode part, and the rear side part of the fine rod-like electrode part is slidably supported in the small-diameter guide hole. Electrode for electrical discharge machining. (4) The pipe-shaped electrode part is formed of a pipe-shaped member,
Claim 2: A guide is fixed to the rear inner side of the pipe-shaped electrode part in the pipe-shaped member, and a rear side part of the fine rod-shaped electrode part is slidably supported in a guide hole at the center of the guide.
Electrode for electrical discharge machining described.