JPH0313013B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a wire cut electrical discharge machining method and apparatus in which processing is started by automatically forming a processing start hole and inserting a wire electrode into the wire cut electrical discharge machining apparatus. Regarding.

Wire-cut electrical discharge machining equipment does not need to manufacture electrodes corresponding to the machining shape each time it is machined, unlike regular electrical discharge machining equipment, and with the development of numerical control equipment (NC equipment), it is possible to operate unattended for long periods of time. For these reasons, it is now widely used.

When performing contour processing such as cutting dies using a wire cut electric discharge machining device, first a hole for passing the wire electrode through the workpiece is formed, and the wire electrode is inserted into the hole for passing the electrode. At the same time, the wire electrode is usually stretched in a straight line with an appropriate tension between a pair of electrode guides provided at the ends of two arms, and during processing, there is no tension between the wire electrode and the workpiece. A machine that supplies machining fluid and applies intermittent voltage pulses between the two to generate electrical discharge, and then applies machining feed to the wire electrode or workpiece using a numerical control device, thereby machining the desired contour. It is.

However, it is extremely difficult to form a straight and uncurved hole for electrode insertion in a thick workpiece, and the machining process is performed using a machine such as a drill press or jig borer that is separate from the wire cut electric discharge machining equipment. If this is done using a target drilling device or a drilling device using electric discharge or electrolytic machining, the positioning of the workpiece must be performed twice, once during drilling and once during wire cut electrical discharge machining, which requires skill. The problem was that it was not long and it took a long time. Furthermore, the wire electrode has a diameter of 1 mm or less, usually
This is an extremely thin wire of about 0.05 to 0.3 mm, which must be accurately inserted into the electrode insertion hole formed in the workpiece before processing begins, and stretched in a straight line between a pair of guides. There was also the problem that it was extremely difficult.

In order to solve the above-mentioned problems, it has been proposed that the hole for inserting the wire electrode be drilled by machining or electrical machining while the workpiece is positioned and attached to a wire cut electric discharge machine (for example, Before starting machining (Japanese Unexamined Patent Publication No. 48-33493, Utility Model Publication No. 51-31195, etc.), it is possible to move freely in the axial direction of the machining head of wire cut electrical discharge machining or to the drilling head provided so that it can be retracted and taken out. A hole for inserting a wire electrode is made in the workpiece using the attached drill tool or a capillary electrode for electric machining, and then the tool or the rod-shaped hollow capillary electrode is inserted into the machined part. Then, the wire electrode supply head is guided to the processing part, and the wire electrode is sent out and inserted into the electrode insertion hole machined in the workpiece, and the tip of the penetrating wire electrode is engaged with a recovery device to recover it. In this way, when the wire electrode is stretched in a straight line by a pair of guides on both sides of the workpiece, a relative feed is applied to the wire electrode and the workpiece to start electrical discharge machining. A wire cut electrical discharge machining device equipped with an automatic wire electrode insertion device was developed.

In the above case, it is preferable that the pair of guides provided on both sides of the workpiece be provided close to the workpiece, so that the wire electrode does not pass through the electrode insertion hole of the workpiece. As the guide on the side that comes out, a conventional die guide etc. can be used as is, or in the case of a V-groove sliding contact guide, the guide can be retracted slightly or can be opened and closed, or Although it can be used if the holding piece against the V-groove can be retracted, the guide on the electrode supply side is designed to allow the use of a tool for drilling a hole for electrode insertion or a thin tubular electrode. The distance for retraction of die guides, V-groove guides, their holding pieces, etc. is large due to their position, or
Because it is necessary to configure the groove guide and the composite die guide to a large degree of opening/closing, even if positioning is performed with a high degree of precision, there are of course problems such as the curvature and curl of the wire electrode, the shape of the cut end, etc. This is because the wire electrode is fed out with its tip free while being in contact with a guide, the inner circumferential wall of the electrode insertion hole, and other inclusions such as a contact energizing pin. The automatic electrode insertion device not only requires complicated work for insertion, but also has the problem that the operation of inserting the wire electrode into the electrode insertion hole or the operation of inserting it through the guide is not always performed well. It was hot.

That is, in the above device, the formation of the insertion hole and the insertion of the wire electrode are divided into two steps, and the processing of the inner circumferential wall surface of the insertion tube by the outer circumferential wall surface portion of the above-mentioned thin tube-shaped electrode is performed to reduce the roughness of the processed surface. Even if the insertion hole is small and can be carried out fairly well, the diameter of the above-mentioned insertion hole is small, around 1 mmφ or less at most, and if the thickness of the workpiece is several tens of mm or more, it is easy to insert the wire electrode. Therefore, even if the electrode insertion hole is successfully drilled, it is necessary to insert the wire electrode inside the hole and ensure that the tip of the wire electrode is inserted or positioned into the small guide die or other guide located beyond the hole. It was quite difficult to do so.

Furthermore, since the above-mentioned drill tool and device for moving the thin tubular electrode up and down are attached to the upper arm or the machining head, there is a problem that the entire upper structure of the wire-cut electric discharge machining apparatus becomes large. It was hot.

The present invention has been made based on the above-mentioned viewpoints, and its purpose is to process even thick workpieces, hardened workpieces, cemented carbide workpieces, etc. Also, the electrode insertion hole can be formed in a short time, and the wire electrode can be inserted into the formed electrode insertion hole substantially simultaneously with the processing and formation of the electrode insertion hole. By doing so, it is possible to insert the wire electrode reliably, and the wire electrode is fed out from the tip portion of the thin tubular electrode that has been formed by processing the electrode insertion hole and penetrated to the other side of the workpiece. The tip of the electrode only needs to pass through a predetermined position to the guide, energizing device, and tensile force applying and collecting means, so it is more convenient than the conventional electrode insertion hole that needs to be inserted. Therefore, even if the guide on the other side of the workpiece is a small guide die, the wire electrode can be inserted reliably, and the wire electrode can be inserted in a straight line using a pair of guides. It is an object of the present invention to provide a wire cut electric discharge machining method and apparatus which enables highly accurate automatic machining because the wire can be stretched over the wire, and furthermore, the entire apparatus can be configured compactly.

The above purpose is to attach a capillary electrode to a chuck provided on a column or arm of a processing device so as to be able to move up and down, and to apply wire cut electrical discharge machining to a desired workpiece. A wire electrode is inserted through the chuck, and the wire electrode is held by a clamp provided on the member supporting the chuck so that the wire electrode is processed and fed in the axial direction together with the capillary electrode, and then the tip of the wire electrode is attached to the capillary electrode. cutting it so that it is substantially flush with the tip portion of the electrode, supplying machining fluid to the center hole of the capillary electrode, and applying a voltage pulse while the tips of the capillary electrode and the wire electrode face the workpiece, A pore for electrode insertion is formed while processing and feeding the capillary electrode, and after completing the penetrating process of the pore for electrode insertion, the power supply to the capillary electrode is stopped, and the grip of the wire electrode is stopped. This is accomplished by releasing the wire electrode, sending the wire electrode to a wire electrode take-up device and stretching it, and then pulling out the thin tubular electrode from the electrode insertion hole.

The above object further provides a chuck that removably supports a capillary electrode having a central hole for passing a wire electrode and a machining fluid therein, a holder that supports the chuck in a vertically movable manner, and a wire electrode supply device that inserts the wire electrode into the center hole of the electrode; a lifting device that supports the holder so as to be able to move up and down; A clamp that holds the wire electrode so that it is processed and fed in the axial direction together with the thin tubular electrode, and a cutter that cuts the wire electrode protruding from the tip of the thin tubular electrode in substantially the same plane as the tip of the thin tubular electrode. and a power supply circuit that supplies electrical discharge machining voltage pulses to the thin tubular electrode when machining a small hole for electrode insertion, and supplies electrical discharge machining voltage pulses to the wire electrode during wire cut electrical discharge machining, and Achieved by an electrical discharge machining apparatus equipped with a wire electrode take-up device that is provided at a position facing the thin tube-like electrode and takes the wire electrode sent out from the tip of the thin tube-like electrode to the machining part along a desired path. be done.

Hereinafter, details of the present invention will be specifically explained with reference to embodiments of the drawings.

FIG. 1 is an explanatory diagram showing a state in which a wire cut electrical discharge machining apparatus according to the present invention is machining a hole for inserting an electrode into a workpiece, and FIG. An explanatory diagram showing the state in which the general pore has been machined and the wire electrode has been inserted. Figure 3 is an explanatory diagram showing the state when wire cut electric discharge machining has started. Figure 4 is the machining fluid nozzle unit for opening and closing. FIG.

In FIGS. 1, 2, 3, and 4, 1 has a wire electrode 2 with a diameter of about 0.05 to 0.4 mm inside.
A thin tubular electrode having a predetermined length and having a hole 1a through which the machining fluid can be inserted and passed through and can be flow-injected, 3 and 4 are opening/closing machining fluid nozzle units, 3a and 4a are split nozzles, and 3b , 4b is a sealing member, 4c is a machining fluid supply hole, 5 and 6 are cutters operated by a solenoid (not shown), 7 is an electrode holder, 8 is a V-shaped electrode guide, 9 is a spring, 10 and 11 are the opening/closing holes mentioned above. 12 is a nozzle device attached to the lower arm 13;
is the nozzle body, 15 is the nozzle, 16 is the cap nut,
17 is a die guide, 17a is a guide holder, 1
8 and 19 are power supply pins that can be moved back and forth, 20 is a spring provided as necessary, 21 is a rubber valve, 2
2 is a stem holder that holds a capillary electrode mounting chuck 25 consisting of a stem 23 and a tightening nut 24; 22a is a machining fluid supply hole formed in the stem holder 22; 26 is a bag nut; 27 is a stem an anvil attached to the upper end of the holding body 22;
8 is an adjustable clamp screw for fixing the wire electrode provided opposite to the anvil 27; 28A;
29 is a motor, and 29 is a stem holder 22 which is held at a required fixed part such as the upper arm of the wire cut electric discharge machine or the upper machining head held on the upper arm.
A hydraulic cylinder 30 moves the machine up and down with respect to a workpiece mounting table (not shown), which acts as a brake roller when the motor is stopped or rotating at a predetermined speed, and when the motor is in control such as sequence control. A brake roller and capstan that acts as a capstan when stopped or rotating downward; 31 is a pinch roller; 32 is a capstan for taking up the wire electrode and applying tension; 33 is a pinch roller; 34 is a rubber valve; 35 is a workpiece,
36 is an energizing shoe that supplies power to the capillary electrode 1;
37 is an O-ring.

The capillary electrode 1 is detachably attached to a capillary electrode mounting chuck 25 composed of a stem 23 and a tightening nut 24, and the capillary electrode 1 is worn out, the worn out tubular electrode 1 can be reattached by loosening the tightening nut 24,
Preferably, the device is configured to be an automatic electrode exchange type so that it can be replaced with a new capillary electrode 1.

The stem 23 is attached to a stem holder 22 and is configured to be moved up and down with respect to a fixed workpiece 35 by the action of a hydraulic cylinder 29 that supports the stem holder 22.

The opening/closing machining fluid nozzle units 3 and 4 are formed with split nozzles 3a and 4a, seal members 3b and 4b, and machining fluid supply holes 4c, etc., and are diametrically controlled by the action of hydraulic cylinders 10 and 11. It is configured so that it can be opened and closed. Further, an electrode holder 7 configured to be acted on by the elastic force of a spring 9 is placed in the central part of the interior of the nozzle unit 3, and a transverse electrode holder 7 is provided in a portion of the other nozzle unit 4 that faces the electrode holder 7. An electrode guide with a V-shaped surface is attached to determine the position of the wire electrode 1 above the workpiece 35 during wire cut electrical discharge machining, and to hold the wire electrode 1 in a straight line.

The nozzle body 14 has a mounting flange 14a, a liquid reservoir chamber 14b, and a machining fluid supply hole 14c, and a nozzle 15 is fitted into the nozzle body 14 so as to be able to slide freely in the axial direction of the wire electrode.
0 and the cap nut 16 are installed in sequence. Thereafter, this nozzle device 12 is attached to the mounting flange 14a.
It is attached to the lower arm 13 with a mounting bolt or the like (not shown).

In the wire-cut electrical discharge machining apparatus according to the present invention, the process of forming the electrode insertion hole through which the wire electrode 2 is inserted into the workpiece 35 and the process of passing the wire electrode into the take-off device after forming the hole are performed. The process from reaching engagement to machining the workpiece 35 by wire cut electrical discharge machining will be described.

As shown in FIG. 1, when forming an electrode insertion hole through which the wire electrode 2 is inserted into the workpiece 35, the brake roller/capstan 30 operates as a capstan, and the hole 1a of the thin tubular electrode 1 is filled with the brake roller/capstan 30. A wire electrode 2 is inserted therethrough.

When the wire electrode 2 advances through the hole 1a of the capillary electrode 1 and its tip protrudes a predetermined length from the tip of the capillary electrode 1, the wire electrode 2 is removed by the brake roller/capstan 30.
At the same time, the clamp screw 28 provided at the upper end of the stem holder 22 is
8A, the wire electrode 2 is held so as to be sent in the axial direction by the movement of the holder 22 together with the capillary electrode 1, and at this time, the capillary electrode 1
If there is a discrepancy, such as the tip of the cutters being above the positions of the cutters 5 and 6, the hydraulic cylinder 29 is operated to adjust them to match, and then the cutters 5 and 6 are operated by solenoids (not shown). After the wire electrode 2 is cut so as to be approximately flush with the tip of the thin tubular electrode 1, the nozzle units 3 and 4 are opened as shown in the figure, and the start hole is machined by lowering the electrode 1. possible. On the other hand, the workpiece 35 is subjected to numerical control (not shown) so that the position of the electrode insertion hole for starting machining includes a predetermined position with respect to the capillary electrode 1, which is predetermined by scribing or the like. It is sent via a processing table by a device, etc., and is positioned and installed.

The above is a case where when the thin tubular electrode 1 is replaced due to wear or the like or is newly attached to the chuck 25, the operation is started with the tip of the wire electrode 2 not reaching the base position of the electrode 1. When replacing the electrode 1, etc., the wire electrode 2 can be manually inserted into the electrode 1, and then the electrode 1 can be attached to the chuck 25, and in many cases, , at the end of the previous wire cut electric discharge machining, the wire electrode 2 is cut at the tip position on the electrode 1 side, which is the supply side, and the wire electrode 2 is in a kind of standby state for the next machining operation. In such a case, the operation and process of inserting the wire electrode 2 into the electrode 1 has been completed.

Voltage pulses for electric discharge machining are supplied from a power supply circuit (not shown) to the capillary electrode 1 via the current supply shoe 36 and to the wire electrode 2 via the clamp screw 28 as necessary. At the same time, a downward moving motion is applied by the hydraulic cylinder 29 via the stem holder 22 and the stem 23, and the same machining fluid as that for normal wire cut electric discharge machining is applied from the hole 1a of the thin tubular electrode 1 to the workpiece 3.
While being supplied to the processing section 5, the electrode insertion hole is processed.

Processing of a hole for electrode insertion into the workpiece 35 using the thin tubular electrode 1 is described in, for example, JP-A-56-69033, except that the wire electrode 2 is inserted through the electrode 1.
This is performed by high-speed machining using deep hole electric discharge machining as described in detail in the above publication, and machining fluid is supplied under pressure from the supply hole 22a at least 10 to 20 kg/cm ² or more, and is preferably Although not shown in the figure, the process is performed by applying ultrasonic vibration to the thin tubular electrode 1 as described in the above-mentioned publication and by applying constant speed or servo feed from the cylinder 29. In this way, the injection of high pressure machining fluid and Furthermore, by applying vibration, machining of deep holes, which could not be machined smoothly in the past, can be performed smoothly and at high speed even in hardened steel, cemented carbide, etc., and even on thick workpieces 35. A straight and unbent pore for electrode insertion can be formed in a short time.

Note that when machining this electrode insertion hole, the wire electrode 2 is formed into a thin tubular shape, not only when the wire electrode 2 is connected to some kind of electric discharge machining power source, but even when the power source is not connected. Since the tip of the wire electrode 2 may be worn out due to being in some kind of contact with the electrode 1, the length of wear and retreat of the tip of the wire electrode 2 relative to the tip of the capillary electrode 1 may reach, for example, approximately several mm or more. Then, during the drilling process, the clamp by the clamp screw 28 is temporarily released and the wire electrode 1 is sent out by the capstan 30 and the pinch roller 31, and the tip is corrected so that it is near the tip of the tubular electrode 1. It is better to leave
This is desirable because the subsequent insertion and setting of the wire electrode 2 into the guide etc. becomes reliable.

When the electrode insertion hole through which the wire electrode 2 is inserted is formed in the workpiece 35, the motor 28A
actuates, the grip of the wire electrode by the clamp screw 28 is released, and the tip of the wire electrode 2, which is near the tip of the tubular electrode 1 and has already been inserted through the electrode insertion hole together with the tip of the electrode 1, is released. is sent toward the nozzle device 12 by the capstan action of the brake roller and capstan 30,
After being inserted and captured by the die guide 17, the capstan 3 passes through the hole 17b of the guide holder 17a, passes through the rubber valve 21, and the pinch roller 33 approaches and separates the capstan 3.
When the wire electrode 2 reaches and engages the wire electrode pulling device consisting of the wire electrode 2 and others, the wire electrode 2 is forcibly pulled from the tip, and the wire (not shown) installed in the bed etc. of the wire cut electric discharge machining apparatus main body is removed. Collected in an electrode collection box, etc.

When the wire electrode 2 is taken up by the take-up device as described above, the hydraulic cylinder 29 operates to move the stem holder 22 upward and raise the thin tubular electrode 1 upward, and accordingly, the opening/closing type The machining fluid nozzle units 3 and 4 are closed by the action of the hydraulic cylinders 10 and 11, and the wire electrode 2 is attached to the electrode retainer 7 of the V-shaped electrode guide 8 inside the open/close type machining fluid nozzle units 3 and 4. This allows it to be moved freely. And the nozzle body 14
Power supply pins 18 and 1 in contact with wire electrodes 2 in
Wire-cut electrical discharge machining is performed while a voltage pulse for electrical discharge machining is supplied from 9, and machining fluid supplied from the machining fluid supply hole 4c of the open/close type machining fluid nozzle unit 4 is supplied to the machining portion of the workpiece 35. It will be done.

Note that during normal machining, the current-carrying pins, guides, etc. reach a considerable temperature due to electrical discharge machining current, friction, and the like. However, in the wire cut electrical discharge machining apparatus according to the present invention, the power supply pins 18, 19, the die guide 17, etc. in the nozzle body 14 are sufficiently cooled by the machining fluid passing through the liquid reservoir chamber 14b. Therefore, it can withstand long-term driving.

In addition, when the tubular electrode 1 is worn out and its length becomes equal to or less than the workpiece 35 to be processed,
Wire electrode 2 will be replaced by cutting it at the tip of electrode 1, but if replacing electrode 1 manually, thread the wire electrode 2 hanging down to the tip of chuck 25 through the new electrode 1. However, this is extremely difficult if the electrode 1 is replaced automatically, so in such a case, the hanging wire electrode 2 should be returned to near the base of the stems 23 by reversing the capstan 30. Of course, after that, a new capillary electrode 1 is attached, and the wire electrode 2 is sent out and inserted up to the tip of the electrode 1.

Note that the wire electrode 2 is connected to the guide 17 and the power supply pin 1.
8, 19, if the insertion or setting fails at the rubber valve 21, capstan 32, pinch roller 33, or further ahead electrode pulling device, etc., for example, once the capillary electrode 1 is moved to the position shown in FIG. The wire electrode 2 is pulled up and cut at the tip of the electrode 1, and then the wire electrode 2 that has been inserted to the object to be applied is pulled out manually or with a robot hand, etc. and discarded, and the wire electrode 2 is clamped to the holder 22. And the second
The operation is performed so that the wire electrode 2 is set downward to the position shown in the figure, the clamp of the wire electrode 2 is released, and the insertion and setting of the wire electrode 2 by feeding is attempted again.

Since the present invention is constructed as described above, when the wire cut electric discharge machining method and apparatus according to the present invention are used, the wire electrode can be easily cut even when the workpiece is thick or hardened. A straight pore for electrode insertion that can be passed through can be formed in a short time, and the insertion of the wire electrode into the pore for electrode insertion is already performed at the same time as the formation of the pore for electrode insertion. Therefore, it is sufficient to perform operations such that the tip of the wire electrode is positioned, inserted, and engaged with the guide, electrode pulling device, etc. thereafter, and the probability of success in automatic insertion of the wire electrode is increased. In addition, even if the guide on the other side of the workpiece is a small guide die or the like, the wire electrode can be inserted with high probability, and the wire electrode is stretched in a straight line by the pair of guides. Therefore, highly accurate automatic processing is possible, and furthermore, the entire device can be configured compactly.

Note that the present invention is not limited to the embodiments described above. That is, for example, in this embodiment, the tubular electrode was configured to be moved up and down by a hydraulic cylinder via a stem holder, but it may also be configured to be moved up and down by a motor via a gear. Furthermore, a known power supply method can be used to supply power to the capillary electrode and the wire electrode.
Furthermore, if the structure is such that rotational motion is applied to the tubular electrode while processing the fine hole for electrode insertion,
The processing time for forming the electrode insertion holes can be further shortened and the processing can be carried out reliably. In addition, machining fluid is supplied to the open/close type machining fluid nozzle unit during wire cut electrical discharge machining by clamping and sealing the tip of the tubular electrode 1 with seal members 3b and 4b, without using the hole 4c, through the electrode 1. Alternatively, the power supply pin or power supply roller to the wire electrode may be provided on the upper side of the workpiece, and the guides 8, 17, power supply pins 18, 19, etc. may be provided outside the nozzle unit or nozzle body. The guide 8,
17, for example, Japanese Patent Application No. 58-181234;
194952 or 58-210374, etc., in which the guide hole can be enlarged/reduced or opened/closed, it can also be used as a machining fluid injection nozzle, for example, in Japanese Patent Application No. 58-40949, Various configurations described in 58-40950, 58-70506, etc. can be used, and when machining a small hole for electrode insertion as a machining start hole with a capillary electrode Various modifications are possible, such as providing a guide that guides the position of the tubular electrode on or near the upper surface of the body so that it can move forward and backward to prevent bending of the pores formed in a thick workpiece. The invention can also be applied to a wire-cut electrical discharge machine of a type in which the wire electrode of the illustrated embodiment is turned upside down and fed from the bottom to the top for renewal. In addition, the mounting position of the die, the mounting method thereof, the method of supplying machining fluid, the method of recovering the wire electrode, etc. can be freely changed within the scope of the purpose of the present invention, and the present invention covers all of them. It is inclusive.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing a state in which an electrode insertion hole for inserting a wire electrode into a workpiece is being machined by an automatic wire threading device in a wire cut electric discharge machining apparatus according to the present invention; FIG. 2 is an explanatory diagram showing the state in which the electrode insertion hole has been machined and a wire electrode has been inserted, FIG. 3 is an explanatory diagram showing the state when wire cut electrical discharge machining is started, and FIG.
The figure is an enlarged sectional view of the machining liquid nozzle unit for opening and closing. DESCRIPTION OF SYMBOLS 1... Tubular electrode, 1a... Inner hole, 2... Wire electrode, 3, 4... Open/close type machining liquid nozzle unit, 5, 6... Cutter, 7... Electrode press, 8...
...V-shaped electrode guide, 9,20...spring,
10, 11... Hydraulic cylinder, 14... Nozzle body, 15... Nozzle, 16, 26... Cap nut,
21, 34... Rubber valve, 25... Capillary electrode mounting chuck, 27... Anvil, 28... Clamp screw, 28A... Motor, 29... Hydraulic cylinder, 30... Brake roller and capstan, 3
1, 33... pinch roller, 32... capstan, 35... workpiece, 36... energizing shoe, 3
7...O-ring.

Claims (1)

[Claims] 1. In wire cut electrical discharge machining, a method of forming a fine hole for electrode insertion in a workpiece and automatically inserting a wire electrode into the fine hole for electrode insertion to start electric discharge machining. A wire cut electric discharge machining method comprising the steps described in items (a) to (g) below. (a) The process of attaching a capillary electrode to a chuck that can be raised and lowered. (b) A step of inserting a wire electrode into the capillary electrode. (c) A step of grasping the wire electrode so that it can be moved in the axial direction together with the capillary electrode using a clamp provided on the member supporting the chuck, and cutting the tip portion of the wire electrode protruding from the tip of the capillary electrode. (d) supplying machining fluid to the center hole of the capillary electrode;
A step of machining a pore for electrode insertion while applying a voltage pulse to the tip of the thin tubular electrode and the wire electrode to face the workpiece and feeding the machining process. (e) A step of stopping power supply to the capillary electrode after completing the processing of the electrode insertion hole. (f) A step of releasing the grip on the wire electrode and feeding the wire electrode to a wire electrode take-up device. (g) A step of pulling out the tubular electrode from the electrode insertion hole. 2. A wire cut discharge device characterized by comprising the components described in items (h) to (p) below. (h) A thin tubular electrode with a central hole for passing the wire electrode and processing fluid inside. (i) A chuck that removably supports the capillary electrode. (j) A holder that supports the chuck so that it can be raised and lowered. (k) A wire electrode supply device for inserting a wire electrode into the center hole of the capillary electrode. (l) A lifting device that supports the above-mentioned holding body so that it can be raised and lowered. (m) A clamp that is provided on the holder and grips the wire electrode so that the wire electrode is processed and fed in the axial direction together with the thin tubular electrode only when processing the electrode insertion hole. (n) A cutter for cutting the wire electrode protruding from the tip of the capillary electrode in substantially the same plane as the tip of the capillary electrode. (o) A power supply circuit that supplies a voltage pulse for electric discharge machining to the thin tubular electrode when machining a small hole for electrode insertion, and supplies a voltage pulse for electric discharge machining to the wire electrode during wire cut electric discharge machining. (p) A wire electrode pulling device, which is provided at a position facing the capillary electrode through the workpiece and pulls the wire electrode sent out from the tip of the capillary electrode to the processing part along a desired path. .