JP2000094219A - Extrafine pipe electrode and electrode device for electric discharge machining - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily manufacture and to easily attach without crushing, by providing both a pipe-like shank body of a larger diameter than a pipe electrode attached to an electrode holder, and a middle pipe body allowing fitting of the pipe electrode into its front end side and also allowing fitting of the shank body onto its back end side. SOLUTION: An extrafine and long pipe electrode 1 has an outside diameter of 0.30 mm or less, and an axial length not less than several hundred times as large as the outside diameter. An end of the pipe electrode 1 is fixed to an electrode holder or the like attached to/detached from a machining head of an electric discharge machine through a middle pipe body 4 and a pipe-like shank body 2 such that the pipe electrode 1 is held in a water-tightly sealed state with it electrically contacted with the electrode holder or the like. The middle pipe body 4 has an outside diameter nearly equal to an inside diameter of the pipe-like shank body 2 and has an inside diameter nearly equal to the outside diameter of the pipe electrode 1, while the pipe electrode 1 is fitted into a front end side of the middle pipe body 4 by a prescribed length. A back end side of the middle pipe body 4 is fitted into a front end side of the pipe-like shank body 2 by a prescribed length, while both the front and back fitting parts of the middle pipe body 4 are fixed by glue.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultra-fine and long pipe electrode for electric discharge machining used for drilling a fine and deep hole, particularly an outer diameter of about 0.3 mm or less or a thinner and longer pipe electrode. Is several hundred times or more of the outer diameter, for example, 100 mm
With a pipe electrode of a degree or more, automatic replacement by an automatic electrode replacement device or the like in an electric discharge machine is made possible, and breakage or the like is hardly performed, thereby facilitating manual handling and work processing.

[0002]

2. Description of the Related Art In the processing of fine and deep holes, it is necessary to secure the discharge of processing chips and the like from a processing portion by a high pressure supply jet of a processing liquid using a rod-shaped or linear electrode as a pipe electrode. Is well known, for example, as described in Japanese Patent Application Laid-Open No. 56-69,033, and a mineral oil such as kerosene is used as a working fluid by securing a predetermined amount of a working fluid jet. It has become possible to process fine and deep holes using a system processing fluid.

[0003] Incidentally, as a pipe electrode for processing fine and deep holes, an electrode wear ratio is often used under a high wear condition of about 1: 1, that is, about 100% or more. Mechanical fixation of the fine pipe electrode to the machining head chucking part of the small hole electric discharge machine, electrical electric contact fixation, and high pressure seal contact because it is very long and easily bendable and breakable. Due to the necessity of fixing, etc. and the necessity of processing preparation work that requires skill such as high-precision positioning and guidance when replacing the pipe electrode, etc., processing a plurality of micro holes as many as possible with one pipe electrode As long as possible, at least several tens of outside diameters
0 times or more, about 400 to 500 mm or less, usually about 200
It can be manufactured and finished into a product of about 350 mm.

The outer diameter of the pipe electrode is approximately φ
When the diameter is about 0.3 mm or more, the outer diameter is about 0.3 mm, and the inner diameter is about 0.12 m.
m, and thus the thickness of the pipe is about 0.09 mm, that is, about 0.1 mm or more, so even if the material is copper or a copper alloy-based material, the above mechanical fixing operation is not so difficult. However, the outer diameter of the pipe electrode is φ0.3
mm smaller than about 0.25 mm, for example, the outer diameter is φ0.25 mm, the inner diameter is 0.1 mm, the wall thickness is 0.05 mmt, and the same is applied, and the same applies to φ0.15 mm, φ0.
07 mm, 0.04 mmt, and φ0.1 mm, φ0.
Mechanical, electrical, and watertight attachment of a long pipe electrode, such as 04 mm or 0.03 mmt, to a chuck portion or the like was extremely difficult, and it was not uncommon to make Oshaka.

However, in such a case, a pipe or the like is provided on one end side of the minute and long pipe electrode so as to enable the mechanical, electrical and watertight contact and fixing without damaging the pipe electrode. Forming or attaching a shank portion is described in, for example, Japanese Patent Application Laid-Open No. 59-214,518,
JP-A-61-121,824 or JP-A-8-121,824.
It is known as described in 197,337 and the like. However, the first and third prior arts are for the case of using a thin wire electrode in which the electrodes are not pipe-shaped, and the second prior art is for φ0.1 ~.
A cylindrical electrode is used for machining a fine hole of 0.3 mm in diameter, and the cylindrical electrode is provided with a holder having an electric discharge machining fluid flow path,
That is, a discharge generating portion which is connected to and held by the shank and generates a pressure wave in the electric discharge machining fluid flow passage is provided, and the machining fluid is discharged from the tip of the cylindrical electrode.

The above-mentioned second prior art is shown in FIG. 5 when written in a more dimensional manner to the substance. FIG. 5 shows a shank having an outer diameter of about φ1 mm in which the dimension in the direction perpendicular to the length direction of the cylindrical electrode 1 and the holder (electric discharge machining fluid flow path) 2 is approximately 20 times larger than the actual size. 2 is a cross-sectional view of a pipe electrode body in which one end of a pipe electrode 1 having an outer diameter of about φ0.10 mm is inserted and fitted, and when the entire length is, for example, about 250 mm, the shank portion 2 is formed of a machining fluid. A certain length to mechanically fix it so that it can be sent in and sealed watertight, and it can be energized and inserted and removed,
For example, since a length of about 60 mm is required, the length of the portion of the pipe electrode 1 is about 190 mm, and the length of the fitting portion of the shank 1 is, for example, about +20 mm.

[0007]

However, it is surprisingly difficult to insert and fix the pipe electrode 1 to the machining fluid flow passage 2A of the shank body 1 and to perform the work. The fixing in the fitted state is performed by injection of instantaneous adhesive or the like, but in order to maintain a certain degree of energizing contact and to form a precise and strong mechanical fixing state, as will be described later with specific numerical examples, Shank body 2
The dimensional difference (clearance) between the inner diameter of the pipe electrode 1 and the outer diameter of the pipe electrode 1 is about 0.01 mm on one side (0.02
mm) or less. However, the shank body 2 has a very large dimensional accuracy (φ0.1 mm +
0. Unless finished to -0.01 mm), the fine pipe electrode 1 with the shank body 2 which has been made with great care may cause poor accuracy or poor performance due to liquid leakage. Even so, it is difficult to precisely control the inner diameter and the outer diameter at the same time in the manufacture of the pipe (the shank body 2), and it is difficult to produce the drawing. Therefore, as described above, the difference in the outer diameter is about 0.02 mm. The insertion of the pipe electrode 1 into the shank body 2 is considerably difficult, despite the fact that the external dimensions of the pipe electrode 1 are precisely finished, and many of them have buckled and have failed in production. is there.

Also, the work of attaching and detaching the ultrafine pipe of FIG. 5 to and from an electrode holder detachable from a socket or the like of a machining head of an electric discharge machine or a machining head having the electrode holder or the like attached thereto is also required. Automation is extremely difficult due to the shape, size, strength, etc. of the shank body 2 and the pipe electrode 1, and most of them are manually performed by an operator.
The portion of the pipe electrode 1 from the tip of the shank body 2 is extremely small in diameter and long, and it is clear that such a shape and configuration are difficult to handle. A load such as a load is concentrated on the fitting / fixing portion 3 of the pipe electrode 1 which is inserted and fixed by a predetermined length with an adhesive or the like, and an accident such as bending or further bending at the root portion is likely to occur. There was a disadvantage.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and is intended to facilitate manufacture by fitting and fixing between pipe-like objects as a very fine pipe electrode having a shank body portion as an attachment portion. Also, the manufactured ultra-fine pipe electrode with a shank body does not have an extremely easily bent or bent portion like the root portion 3 and, therefore, an electrode holder to be attached to and detached from a machining head of an electric discharge machine, or An ultra-fine pipe electrode with a shank, which does not collapse or break on mechanical, electrical contact and water-tight fixing and holding means such as a collet provided in advance on the head, and which is easy to mount. It is an object of the present invention to provide an electrode device having an extra-fine pipe electrode holder equipped with an extra-fine pipe electrode for automatically replacing a processing head electrode.

[0010]

According to the present invention, there is provided a pipe electrode having an outer diameter of 0.30 mm or less and a length of several hundred times or more of the outer diameter. ,
A pipe-shaped shank body having a larger diameter and a predetermined length than the pipe electrode mechanically fixed to an electrode holder, and having an outer diameter substantially equal to the inner diameter of the shank body,
A pipe body having an inner diameter substantially equal to the outer diameter of the pipe electrode, comprising an intermediate pipe body that fits and fixes the pipe electrode on a tip end side and fits and fixes a rear end side on the pipe-shaped shank body. It is characterized by comprising.

Further, the present invention provides the above (1), wherein
(2) The pipe electrode has an outer diameter smaller than φ0.30 mm, φ0.25 mm or less, and a projection length from the tip of the intermediate pipe body is at least 100 mm or more.

Further, the present invention provides the above (1) or (2)
And (3) the fitting and fixing of the intermediate pipe body to the shank body and the fitting and fixing of the pipe electrode to the intermediate pipe body are performed by bonding with an adhesive such as α-cyanoacrylate.

Further, according to the present invention, in the above (1), (2) or (3), (4) the intermediate pipe body is inserted and fixed to the shank body, and the intermediate pipe body is provided at the tip end side of the shank body. Is set in a state in which the front end side is extended by a predetermined length.

Further, according to the present invention, in the above (1), (2) or (3), (5) the fitting and fixing of the intermediate pipe body to the shank body is performed by attaching the intermediate pipe body to a tip end side of the shank body. The front end side extends a predetermined length, and is inserted and set to be substantially the same length at the rear end side.

Further, the present invention provides the above (1), (2),
(3) In (4) or (5), (6) the outer diameter of the shank body is several mm or less, and is substantially φ0.5 mm to φ.
2.0 mm.

Further, the present invention provides the above (1), (2),
In (3), (4), (5), or (6), (7)
The pipe-shaped shank, the intermediate pipe and the pipe electrode are made of copper or a copper alloy.

Further, the present invention provides the above (1), (2),
(3) In (4), (5), (6), or (7), (8) the intermediate pipe is formed of a multi-stage pipe that can be sequentially inserted and fixed. .

According to another aspect of the present invention, there is provided a pipe electrode having an outer diameter of 0.30 mm or less and a length of several hundred times or more of the outer diameter. A pipe-shaped shank body having a sufficiently large diameter and a predetermined length, a pipe body having an outer diameter substantially equal to the inner diameter of the shank body and an inner diameter substantially equal to the outer diameter of the pipe electrode, In an electrode holder of an ultra-fine pipe electrode for electric discharge machining comprising an intermediate pipe body in which an electrode is inserted and fixed and a rear end side is inserted and fixed in the pipe-shaped shank body, a hollow columnar body as a whole is used. Wherein the ultrafine pipe electrode is coaxially inserted in a state in which the intermediate pipe body extends to the front end side, and a state in which the rear end of the shank body projects to the rear end side. , Fit the tip from the tip side The insertion guide portion of the shank body, and a central hollow portion shank body through the collet which is inserted from the rear end opening in the seal Elastic blocks having a shank member insertion hole is further inserted filled into the collet rear,
A piston portion that is screwed into the rear opening end and crushes and opens the block by screwing in, a coaxial insertion hole through which the shank body is inserted, and a lid body that has an extended guide portion that extends the insertion hole rearward; Characterized by comprising:

[0019]

FIGS. 1A and 1B are longitudinal sectional views of an EDM micro-pipe electrode according to a different embodiment of the present invention, respectively. The same parts or portions as those described in FIG. The same reference numerals are given, and the dimensions in the direction perpendicular to the electrode axis direction are shown to be approximately 20 times larger than the actual size.

That is, 1 is an outer diameter of about φ0.30 mm or less, smaller than φ0.30 mm, and a minimum φ0.05.
mm or more, usually about 0.10 mm or more, and the axial length is several hundred times or more of the outer diameter, at least 1
About 00 mm or more, about 400 mm to about 500 mm or less, usually about 200 mm to about 350 mm extra-fine, long pipe electrode, usually made of copper alloy or copper alloy containing copper or brass suitable as an electric discharge machining electrode material, but desired copper In addition to tungsten, silver-tungsten or the like is also used.

The ultra-fine and long pipe electrode 1 is fixedly held at one end to a mechanical holding means such as an electrode holder which is attached to and detached from a machining head of an electric discharge machine or a collet which is previously mounted on the machining head. Furthermore, maintaining a predetermined electrical contact with the electrode holder, etc., and sealing and holding it in a desired watertight manner with rubber packing or the like is a difficult operation requiring skill even if a temporary command or any jig is used. Therefore, accidents such as crushing, bending, and breakage of the pipe electrode 1 caused by holding or pressing the pipe electrode 1 are likely to occur. Therefore, as described above, the length of the mounting and holding portion is about 60 mm and the outer diameter is several m.
m or less, copper, brass with a diameter of about φ2.0 mm to φ2.0 mm, or a shank part 1 which may be an iron-based alloy such as stainless steel is used. It seems that it did not go well in terms of surface, and it seems that it is not practically used with a very fine pipe electrode.

For this reason, reference numeral 4 denotes an intermediate pipe body introduced and set according to the present invention, which may be made of the same copper as the pipe electrode 1. However, since it is not directly used for electric discharge machining, if it has conductivity, the above-mentioned shank body is used. 2 may be made of brass or an iron-based alloy such as stainless steel.
Has an outer diameter substantially equal to the inner diameter of the shank body, and has an inner diameter substantially equal to the outer diameter of the pipe electrode 1,
As shown in the figure, the pipe electrode 1 is inserted into the front end side of the intermediate pipe body 4 by a predetermined length, for example, about 10 mm, and the rear end side is inserted into the front end side of the pipe-shaped shank body 2 if desired. A predetermined length of insertion, and the respective insertion portions before and after the intermediate pipe body 4 are, for example, an instant adhesive such as α-cyanoacrylate or various, preferably a high-flow or high-permeability quick-curing adhesive. Is to be adhered and fixed.

In either case of FIGS. 1A and 1B, the intermediate pipe body 4 has a front end on which the pipe electrode 1 is inserted and fixed, and has a predetermined length coaxially forward from the front end of the shank body 2. For example, about 10 mm: as a configuration that is fitted and fixed to the shank body 2 in an extended state or more, for example, a structure in which a resistance similar to the bending resistance of a pipe spliced fishing rod is provided, and such a drag effect is obtained. In order to provide a larger joint, the intermediate pipe body 4 may be a multi-stage joint in which the intermediate pipe body 4 is sequentially fitted with a smaller diameter or vice versa. or,
In the embodiment shown in FIG. 1A, the rear side of the intermediate pipe body 4 is configured to be long, and the flow path 2 of the machining fluid of the shank body 2 is formed.
A is inserted and filled over the entire length, and the shank body 1 is strengthened in rigidity and strength so as to withstand hard use. On the other hand, in the embodiment shown in FIG. 1B, the length of the rear side of the pipe body 4 is desirably shortened so that the flow passage 2A of the shank body 2 is hollowed out.
/ Cm2 to 80 kg / cm2, the supply pressure of the working fluid reduces dropping in the flow path of the shank body 2 and maintains the desired supply of the working fluid in a stable and smooth manner. The machining speed is also to be increased by electric discharge machining.

FIG. 2 is an explanatory view of an embodiment of the dimensions and lengths of each part of the ultrafine pipe electrode of the present invention in each length direction. The pipe electrode 1 used is 200 mm, and the intermediate pipe body is 70 m.
m, the shank body 2 having a length of 60 mm is fitted and fixed as shown in FIG. 1A, and the overall length is 250 mm and the effective length of one pipe electrode portion is 180 mm. FIG. 3 shows an outer diameter φ0.25 m having the above-mentioned length specification.
m, φ0.20mm, φ0.15mm, and φ0.10
mm shank body 2 and intermediate pipe body 4
3 shows an example of the dimensions of each outer diameter, inner diameter, and wall thickness.

In this case, the target value of the outer diameter is set to φ1.0 + 0 to −0.01 mm so that the collet holding and fixing of the electrode holder and the like can be accurately performed as described above.
As described above, the outer peripheral shape and dimensional accuracy can be finished by drawing with emphasis on the outer diameter control, while the intermediate pipe 4
Is drawn by a drawing process with an emphasis on inner diameter control, and if necessary, an empty drawing process for finishing the outer periphery is performed.

Further, the pipe electrode 1 is made of φ as in the present invention.
In the case of an ultra-fine long pipe such as 0.30 mm or less,
It is necessary to adopt a manufacturing method that considers the securing of the inner diameter. To this end, for example, there is a manufacturing method described in 1998 Patent Application No. 122,973 proposed by the present inventors. However, the pipe electrode 1 has an outer dimension and a surface by repeated drawing and drawing processes. The quality is precisely finished.

Using the shank body 2, the intermediate pipe body 4, and the pipe electrode 1 manufactured as described above, the ultrafine pipe electrode of the present invention is assembled and manufactured as follows. The shank body 2 is held by a fixed holding portion or a hand so as to be able to be visually observed in an enlarged manner by a microscope, a projector, or the like, and the intermediate pipe body 4 is fitted into the shank body 2 in a state where the intermediate pipe body 4 has a predetermined length and the distal end side has a predetermined length. In this case, in the dimension example of FIG.
The difference between the inner diameter of the shank body 2 and the outer diameter of the intermediate pipe body is 0.02 mm in diameter and 0.015 mm in the case of φ0.15 mm pipe electrode when producing an ultrafine pipe electrode of m and φ0.20 mm. In case of .10mm pipe electrode
014 mm, but the outer diameter of the intermediate pipe body 4 is φ
Even in case of 0.10mm pipe electrode 1, φ0.416m
m, the wall thickness is 0.148 mmt, which is sufficiently rigid, so that the insertion into the shank body 2 can be performed with a considerably high success rate.

Insertion of the pipe electrode 1 from the front end side of the intermediate pipe body 4 inserted in a state of extending a predetermined length from the front end of the shank body 2 is a fine precision operation. Since the inner diameter of the pipe body 4 and the outer diameter of the pipe electrode 1 are precisely controlled and finished, the inner and outer diameter difference of 0.02 mm, which is almost the same as the inner and outer diameter difference between the shank body 2 and the intermediate pipe body 4, is obtained. By being given and manufactured,
The pipe electrode 1 can be fitted with a high success rate without causing bending, breakage, and crushing of the pipe electrode 1.

Then, the intermediate pipe body 4 and the pipe electrode 1
Each time: After inserting the pipe electrode 1 and adjusting the insertion state, an instantaneous adhesive such as α-cyanoacrylate is injected and fixed. When a quick-setting adhesive is used as the adhesive, the adhesive may be applied to the surface of the intermediate pipe body 4 to be inserted in advance or while being inserted, depending on the type of the adhesive. And, as described above, the shank body 2 and the intermediate pipe body 4,
Further, since the insertion and assembly between the intermediate pipe body 4 and the pipe electrode 1 is easy to manufacture, each insertion gap can be reduced, and there is no problem in conduction and sealing between the pipe bodies. For fixing the pipes, particularly between the intermediate pipe 4 and the pipe electrode 1, in particular, in the case of a very fine pipe electrode, using a low melting point alloy such as solder requires work hardening by drawing and the like. Anneal the pipe electrode 1
It is preferable to avoid it because it may be bent.

FIG. 4 shows the ultra-fine pipe electrode of the present invention,
The electrode holder 10 is inserted and fixed in the pipe electrode holder 10.
FIG. 3 is a cross-sectional view showing a state in which is mounted on a machining head 5 of a pore electric discharge machine from an electrode holder magazine by an automatic electrode changing device or the like.

In the figure, reference numeral 10 denotes a hollow columnar body as a whole, in which a very fine pipe electrode has the intermediate pipe body 4 extended to the front end side and the rear end of the shank body 2 to the rear end side. An electrode holder configured to be inserted coaxially with a protruding portion, wherein the insertion guide portion 11 of the shank body 2 is inserted into the distal end portion from the distal end side, and is inserted from the rear end opening into the central hollow portion. And a plate-shaped elastic washer 13 made of rubber or the like, and a seal elastic block 14 also made of rubber or the like inserted and filled in the rear part thereof and having a shank body insertion hole.
And a piston portion 15A which is screwed into the rear opening end and crushes and opens the block 14 by screwing, and a coaxial insertion hole 15B for inserting the shank body 2 therethrough.
And the guide portion 15 extended by extending the insertion hole 15B rearward.
C having a lid 15.

The electrode holder 10 loosens the screw of the lid 15 to have a gap of about 1 to 2 mm from the trailing edge, as shown in the figure, to release the collapse of the seal elastic block 14. The shank insertion hole of the block 14 is opened, and the insertion hole 15B of the lid 15 and the insertion guide portion 11 are formed.
The holes are aligned in a straight line and the collet 12 is opened, and the ultrafine pipe electrode is inserted from the shank 2 through the hole of the guide portion 11, and the collet 12 and the elastic washer 1 are inserted.
3 and the hole of the cover 15 through the hole of the block 14.
When the cover 15 is screwed in at a place where it passes through the guide portion 15C and extends a predetermined length from the rear end of the guide portion 15C, the collet 12 is pushed down and closed by the anti-crushing force of the elastic block 14, and the shank body 2 is held. While fixing and holding the shank body 2 by crushing deformation of the block body 14,
Between the outside and the inside of the lid 15 and between the shank 2 and the insertion hole 15
The gap between the inside and the outside is sealed, and a high-pressure machining fluid supplied to the machining fluid flow passage 5A of the machining head of the fine hole electric discharge machine is caused to flow from the rear end of the shank body 2 into the ultrafine pipe electrode, thereby forming the electrode 1 It discharges at a predetermined flow rate from the tip. In the above case, the screwing between the hollow columnar body of the electrode holder 10 and the lid 15 may be based on the screwing of a screw formed on the outer circumference of the hollow columnar body and the inner circumference of the lid 15, and may be changed to each part. Can be implemented.

[0033]

As described in detail above, according to the present invention,
As an extra-fine pipe electrode having a shank body part as an attachment part, it is easy to manufacture by mutual fitting between pipe-like bodies,
Also, the manufactured ultrafine pipe electrode is hardly broken at the shank body fitting / fixing portion or the like, and the ultrafine pipe electrode of the shank body of the present invention is attached to a machining head of a pore discharge machine by manual or automatic exchange means. It is possible to provide an electrode device having an electrode holder that is exchangeably mounted.

[Brief description of the drawings]

FIGS. 1A and 1B are longitudinal sectional views of an electric discharge machining ultrafine pipe electrode according to a different embodiment of the present invention.

FIG. 2 is an explanatory view of the embodiment of the dimensional length of each part in the length direction of the ultrafine pipe electrode of the present invention.

FIG. 3 is an example of the inner and outer diameters and the wall thickness of each part of each of the pipe diameter electrodes of the ultrafine pipe electrode of the present invention.

FIG. 4 is a cross-sectional view for explaining one embodiment of an electrode device in which the microfine pipe electrode of the present invention is mounted on an electrode holder.

FIG. 5 is an explanatory cross-sectional view of a conventional ultrafine pipe electrode.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 (Extra fine) pipe electrode 2 Shank body 2A Working fluid flow passage 3 Fitting / fixing part 4 Intermediate pipe body 5 Working head 10 Electrode holder 11 Insertion guide part 12 Collet 13 Elastic washer 14 Seal elastic block 15 Cover 15A Piston part 15B Insertion hole 15C Guide part

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3C059 AA01 DA03 DA07 DA13 DC02 DC03 DD01 ED05 HA14

Claims (9)

[Claims] 1. A pipe electrode having an outer diameter of 0.30 mm or less and a length of several hundred times or more of the outer diameter, the diameter being larger than the pipe electrode mechanically fixed to an electrode holder. A pipe-shaped shank body having a predetermined length, an outer diameter substantially equal to the inner diameter of the shank body, and an inner diameter substantially equal to the outer diameter of the pipe electrode, wherein the pipe electrode is fitted on the tip end side. An ultrafine pipe electrode for electrical discharge machining, comprising an intermediate pipe body which is inserted and fixed and a rear end side of which is inserted and fixed to the pipe-shaped shank body. 2. The pipe electrode has an outer diameter of φ0.30 mm.
The micro-pipe electrode for electrical discharge machining according to claim 1, wherein the diameter is smaller than 0.25 mm, and a protruding length from a tip of the intermediate pipe body is at least 100 mm or more. 3. The method according to claim 1, wherein the fitting and fixing of the intermediate pipe body to the shank body and the fitting and fixing of the pipe electrode to the intermediate pipe body are performed by bonding with an adhesive such as α-cyanoacrylate. 3. The ultrafine pipe electrode for electrical discharge machining according to 1 or 2. 4. The method according to claim 1, wherein the insertion and fixing of the intermediate pipe to the shank is such that the distal end of the intermediate pipe extends a predetermined length toward the distal end of the shank. 4. An ultrafine pipe electrode for electrical discharge machining according to 2 or 3. 5. The intermediate pipe body is inserted and fixed to the shank body by inserting the intermediate pipe body at a front end side of the shank body by a predetermined length and inserting the intermediate pipe body at substantially the same length at the rear end side. The ultrafine pipe electrode for electric discharge machining according to claim 1, wherein the electrode is provided and set. 6. The electric discharge machine according to claim 1, wherein the outer diameter of the shank body is several mm or less, and is substantially φ0.5 mm to φ2.0 mm. Extra fine pipe electrode. 7. The pipe-shaped shank body, the intermediate pipe body,
7. The ultrafine pipe electrode for electric discharge machining according to claim 1, wherein the pipe electrode is made of copper or a copper alloy. 8. The discharge according to claim 1, wherein said intermediate pipe body comprises a plurality of multi-stage pipe bodies which can be sequentially inserted and fixed. Extra-fine pipe electrode for processing. 9. A pipe electrode having an outer diameter of 0.30 mm or less and a length of several hundred times or more of the outer diameter, and a pipe-shaped shank having a diameter sufficiently larger than the pipe electrode and a predetermined length;
A pipe body having an outer diameter substantially equal to the inner diameter of the shank body and an inner diameter substantially equal to the outer diameter of the pipe electrode, wherein the pipe electrode is fitted and fixed to the front end side and the rear end side is the pipe. In an ultra-fine pipe electrode holder for electric discharge machining comprising an intermediate pipe body fitted and fixed to a shank body, the entirety is a hollow columnar body, and the ultra-fine pipe electrode has the intermediate pipe body on the tip side. An electrode holder having a configuration in which the shank body is inserted coaxially in a state where the rear end portion of the shank body is protruded toward the rear end side in a state where the shank body is extended. An insertion guide portion, a shank insertion collet inserted from the rear end opening in the central hollow portion, and a seal elastic block having a shank insertion hole inserted and filled in the rear portion of the collet; It comprises a piston portion screwed into the open end and crushing and opening the block by screwing, a lid having a coaxial insertion hole for inserting the shank body and an extended guide portion for extending the insertion hole rearward. An ultra-fine pipe electrode device for electric discharge machining characterized by the above-mentioned.