JP2003071641A - Fine hole electric discharge machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem wherein a guide hole of an electrode guide is apt to be clogged and a worker must frequently clean it to disturb automation of fine hole electric discharge. SOLUTION: A body machine 1 of a fine hole electric discharge device has a spindle device 16, the electrode guide 17, and an automatic tool changer 2 for selectively attaching or detaching an electrode holder 4 from the spindle device 16. A controller automatically and selectively mounts the electrode holder 4 having a fixture 31 having a hard and tough pin 311 for cleaning the electrode guide 17, of a plurality of electrode holders previously set in the automatic electrode changer 2, to the spindle device 16 and scrapes machining chips out of a guide hole in the electrode guide 17 by penetrating the electrode holder 4 into the guide hole while rotating it.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small-diameter tool electrode facing a work piece with a predetermined machining gap, and an electric discharge machining fluid being interposed in the machining gap between the electrode and the work piece. A small hole electrical discharge machine that applies intermittent voltage pulses to repeatedly generate electric discharge, and also applies relative rotation and machining feed in opposite directions to the electrode and the workpiece to form a small hole in the workpiece. In particular, the present invention relates to a fine hole electric discharge machine that can effectively clean an electrode guide.

[0002]

2. Description of the Related Art In fine hole electric discharge machining, usually, as a tool electrode, a fine hole machining electrode having an outer diameter of about 0.1 mm to 3 mm and a length of about 200 mm to 300 mm is used. In particular, a hollow cylindrical pipe electrode is often used as the fine hole machining electrode. A predetermined machining gap is formed between the tool electrode and the workpiece, and a water-based or oil-based electrical discharge machining fluid is passed through the hollow hole of the tool electrode at a high pressure of 1.96 MPa or more, and the tip opening portion thereof is opened. A machining liquid is supplied to the machining gap to perform electric discharge machining. Hereinafter, such a tool electrode will be referred to as a fine hole machining electrode or a pipe electrode as needed, and will be described in distinction from other tool electrodes for electric discharge machining.

Since the fine hole machining electrode has a very small diameter and is easily bent, in order to obtain the positioning accuracy and straightness of the hole to be machined while maintaining the straightness of the fine hole machining electrode, the fine hole discharge is performed. The machining device is provided with an electrode rotating device that rotates the fine hole machining electrode and an electrode guide that supports the tip end side of the fine hole machining electrode at a position as close as possible to the machining surface of the workpiece. Although the clearance between the guide surface of the guide hole formed in the electrode guide body of the electrode guide and the fine hole machining electrode is closely related to the positioning accuracy, consider the outer diameter of the fine hole machining electrode. Even if it tries, it is designed to be less than ten and several μm.

Small hole electrical discharge machining is often used to drill through holes of relatively small diameter. Therefore, it is possible to perform electrical discharge machining under electrical machining conditions where the average machining current density is higher than that of general die-sinking EDM, and the machining feed rate in the machining depth direction in a normal die-sinker EDM machine. A higher feed rate can be obtained. On the other hand, as described above, the fine hole machining electrode has a very small diameter, but since the electric discharge machining is performed under a high value of the electric machining condition, the fine hole machining electrode is greatly consumed and a large number of holes are formed. In order to continuously perform electrical discharge machining of the, it is necessary to replace the fine hole machining electrodes one after another according to wear. Automation is no exception in replacing the fine hole machining electrode, and many modern fine hole electric discharge machines are configured to automatically send out or replace the fine hole machining electrode. There is.

In recent years, as the diameter of the hole to be machined further decreases, an extremely fine hole machining electrode having a diameter of less than 0.5 mm is frequently used. Since such a fine hole machining electrode has lower rigidity than the conventional fine hole machining electrodes, an automatic electrode of the type in which the fine hole machining electrode whose one end is held in the electrode holder is replaced with the electrode holder. Switching devices are often used. This automatic electrode exchange device has several improvements to the unique features of small hole electrical discharge machining, such as the overall small and lightweight electrode holder and small hole machining electrode. Except for the above, the basic technical idea is the same as that of the automatic electrode exchanging device of a general die-sinking electric discharge machine.

By the way, many products are generated by electric discharge machining. In the broad sense, these products are generally referred to as machining waste, but, for example, metal powder removed from a workpiece by discharge energy, material powder of exhausted fine hole machining electrodes, machining by discharge heat. Impurities produced by the decomposition or alteration of part of the liquid are included. When electric discharge machining is performed using a machining liquid for the purpose of cleaning the electric discharge machining medium and the machining gap, most of the machining waste as described above is contained in the machining liquid extruded from the machining gap. This is no exception in fine hole electrical discharge machining. In some cases, the machining fluid is simply jetted and supplied into the machining gap, while in other cases the entire workpiece is supplied so that it is immersed in the machining fluid. Since the liquid is circulated and supplied, the machining liquid is scattered on the electrode guide at some times and soaks the electrode guide provided near the workpiece at some times.

When the machining liquid containing the machining dust is scattered or the electrode guide is dipped, the machining dust adheres to the guide hole and the lower end surface of the electrode guide. The machining waste attached to the lower end surface of the electrode guide is simultaneously guided to the guide hole when the fine hole machining electrode is pulled out from the guide hole. Further, since the fine hole machining electrode is rotated at a predetermined speed, the surface of the fine hole machining electrode and the guide surface of the guide hole rub against each other, and fine scraps of the fine hole machining electrode are generated. As already mentioned, the clearance between the guide surface of the guide hole and the fine hole machining electrode is very small. Therefore, if the adhered machining waste is left as it is, the size of the inner diameter of part or all of the guide hole becomes almost the same as or smaller than the outer diameter of the fine hole machining electrode in a relatively short time. .

In such a state, it becomes difficult to insert the newly replaced fine hole machining electrode into the guide hole of the electrode guide, not only by exchanging the tool electrode by the automatic electrode exchanging device, but also by manual work. It becomes impossible to continue electrical discharge machining. Even so, in the case of a fine hole machining electrode having a diameter of more than 0.3 mm, such a problem is caused, for example, by gradually inserting the machining fluid into the guide hole of the electrode guide while supplying the machining fluid from the hollow hole. Is relatively small, but φ
If a fine hole machining electrode having a rigidity of less than about 0.3 mm and having an extremely small rigidity is forcibly inserted, the fine hole process electrode is naturally bent. Alternatively, when the fine hole processing electrode is pulled out, the fine hole processing electrode may be torn. Moreover, after the working fluid evaporates and dries to leave the remaining working waste completely solidified, it is considerably difficult to remove it, and the electrode guide itself may become unusable. Therefore, the operator who operates the small hole electrical discharge machining device inserts the pin manually or sprays air or cleaning liquid of a predetermined pressure on the guide hole to regularly clean the guide hole and the end surface before machining. The reality is that they are cleaning.

In fact, when electric discharge machining is performed in which hundreds of holes having extremely small diameters are continuously formed, in many cases, the consumed fine hole machining electrode is automatically replaced with a new fine hole machining electrode. At times, the guide hole is clogged, so that the electrode for machining the fine hole fails to be inserted into the guide hole, and the continuous fine hole electric discharge machining by the automatic operation is interrupted. Therefore, even in the small-hole electric discharge machining equipped with the automatic electrode exchange device, the automatic operation is extremely difficult in reality.

[0010]

As described above, the maintenance and inspection work for cleaning the guide hole of the electrode guide is performed by the small hole electric discharge machining which has been purposely provided with an automatic electrode changing device to achieve continuous long-term automatic operation. Therefore, it is a major obstacle to automation, and it cannot be expected to improve work efficiency. Further, the work itself of cleaning by looking into the small guide hole of the electrode guide is a heavy burden on the operator. In view of the above problems, it is an object of the present invention to provide a fine hole electric discharge machining apparatus that can more effectively clean an electrode guide, particularly when using a fine hole machining electrode of φ0.1 mm to φ0.3 mm. And In addition, some advantages obtained in the specific embodiments according to the present invention will be appropriately described in the description of the embodiments.

[0011]

In order to solve the above-mentioned problems, a fine hole electric discharge machining apparatus according to the present invention holds a fine hole machining electrode through an electrode holder and processes the fine hole machining electrode. A machining spindle that descends while rotating with respect to an object to perform electric discharge machining of the workpiece, and an electrode guide device that elevates and lowers with a guide hole that supports the fine hole machining electrode rotatably and vertically. An automatic tool exchanging device including an automatic tool exchanging device for accommodating the fine hole machining electrode in advance and transferring and mounting a desired fine hole machining electrode on and off the machining spindle, wherein the automatic tool exchanging device is , A pin having a diameter substantially corresponding to the diameter of the fine hole machining electrode is stored in the first cleaning jig mounted on the electrode holder, and the cleaning electrode holder is transferred to the machining spindle at predetermined intervals. When mounted, the machining spindle is Characterized by cleaning the guide hole by the inserted into the guide hole lifting of the electrode guide apparatus while rotating the pins of use the electrode holder.

[0012] Preferably, a predetermined cycle for cleaning the electrode guide hole with the pin is performed every time the fine hole machining electrode is replaced. Further, preferably, the diameter of the fine hole machining electrode is 0.1 mm to 0.3 mm.
Is characterized in that.

Also, in the small hole electric discharge machining apparatus of the present invention, a second cleaning jig, which is a nozzle device for jetting a machining liquid into the guide hole of the electrode guide, is placed near the workpiece, and When the pin cleans the guide hole, the machining spindle and the guide device move so that the pin and the electrode guide are positioned immediately above the nozzle device, and the nozzle device applies machining liquid to the guide hole. Characterized by spraying. Preferably, the nozzle device includes a nozzle having an upper end surface that substantially matches the shape of the lower end surface of the electrode guide.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows the outline of a main unit of a small hole electric discharge machine. The fine hole machining electrode EL used for the fine hole electric discharge machining is arranged at a position where the tip end thereof faces the workpiece WP. As the fine hole machining electrode EL, for example,
Using a pipe electrode with a diameter of 0.1 mm, from the working fluid supply device (not shown in FIG. 1) to the hollow hole of the pipe electrode, 7.84
A working fluid of MPa is supplied. It should be noted that the fine hole machining electrode E
A power supply system including an inter-electrode wire and a power supply member for supplying a processing current to each of L and the workpiece WP and a power supply device for processing for supplying a processing energy to the processing gap is the same as the conventional one, and detailed Description is omitted and not shown in the drawings.

The machine 1 of the small hole electric discharge machining apparatus is generally composed of a bed 11, a cross table 12 (relative moving device), and a surface plate 1.
3, a column 14, a processing tank 15, and a spindle device 16. Further, an automatic electrode exchanging device 2 (ATC) is installed in parallel with the main machine 1 of the small hole electric discharge machine.

The bed 11 is a base that is horizontally installed. The cross table 12 includes a table 121 and a saddle 122. The table 121 is reciprocally moved in the horizontal 1-axis direction (X-axis) by the servo motor 12X, and the saddle 122 is reciprocally moved in the other horizontal 1-axis direction (Y-axis) orthogonal to the X-axis by the servo motor 12Y.

The workpiece WP is placed on the table 121 via the surface plate 13. Therefore, the table 121
When the saddle 122 is reciprocally moved in the horizontal two-axis directions, as a result, the workpiece WP is relatively moved in the horizontal two-axis directions with respect to the tool electrode EL.

The column 14 is erected on the bed 11. Instead of the cross table 12, the column 14 may be configured to reciprocate in at least one horizontal axis direction within an allowable range in terms of design. A slider 1 for movably supporting an electrode guide 17 is provided on the front wall surface of the column 14.
A guide rail 141 for guiding the movement of 64 is laid.

The processing tank 15 is mounted on the surface plate 13 by a mounting member.
It is installed so as to surround the workpiece WP clamped by. The processing tank 15 prevents the processing liquid jetted and supplied from scattering outside the machine. Further, depending on the method of electric discharge machining, the machining liquid is stored so that the workpiece WP is immersed in the machining liquid.

The spindle device 16 is a device for moving the fine hole machining electrode EL relative to the workpiece WP in the machining depth direction. The spindle device 16 is at least the machining spindle 1.
61, a chuck 162, and a rotating device 163, and these members form a so-called processing head. The machining spindle 161 is reciprocally moved in the vertical direction (Z axis) along a guide rail 165 laid on the slider 164 by a servo motor (linear motor) not shown, and the rotating device 163 is provided with a small hole together with the electrode holder 4. The processing electrode EL is rotated. The chuck 162 holds the fine hole machining electrode EL together with the electrode holder 4.

The electrode guide 17 is attached to the tip of a support arm member 166 fixedly attached to the lower end of the slider 164 so as to hang down in the direction of the workpiece WP.
The electrode guide 17 moves the slider 164 up and down by a motor (not shown) to move the work surface W of the work WP.
It is moved in the axial direction parallel to the main axis perpendicular to S.

The automatic electrode exchanging device 2 has a magazine 21 for accommodating a plurality of electrode holders 4 for holding the fine hole machining electrodes EL mountable on the spindle device 16, and selectively between the spindle device 16 and the magazine 21. It comprises a transfer device 22 for transferring the electrode holder 4. The magazine 21 includes a magazine table 211 rotatably attached to a column 23 whose one end is firmly fixed to the column 14. A plurality of magazine pots 212 are provided around the outer circumference of the magazine table 211, and as the magazine table 211 is rotated by a rotation device (not shown), the magazine pot 2
12 moves around the outer circumference of the magazine table 212.
The transfer device 22 is a magazine pot 212 of the magazine 21.
The column 2 is mounted so that it can be hung at the appropriate height according to the position of the electrode holder 4 housed therein.
It is attached and fixed to 3. The automatic electrode exchanging device 2 operates according to a signal sent from the control device 5 shown in FIG. 5 when it is determined that the fine hole machining electrode EL used for electric discharge machining has been consumed.

More specifically, the transfer device 22 includes a gripping device 221, a replacement arm 222, and a drive device 223. The gripping device 221 grips the electrode holder 4, and as a preferred embodiment in consideration of the small size and light weight of the electrode holder 4, an opening / closing finger for gripping the electrode holder 4 in the outer peripheral groove of the electrode holder 4 is provided. I have it. The exchange arm 222 uses the gripping device 221 for the magazine 21.
And a main shaft device 16 are reciprocally moved, and are cylindrical piston rods. The drive device 223 is an actuator that reciprocates on the exchange arm 222.

The small-hole electric discharge machining apparatus described above is provided with the following apparatus for cleaning the electrode guide, which is the main part of the present invention. The cleaning jig 3 is a member that scrapes out machining waste from the electrode guide 17 or flushes it with a fluid. For convenience of description, the cleaning jig 3 includes the first cleaning jig 31, the second cleaning jig 31, and the second cleaning jig 31.
In the embodiment of the cleaning jig 32 or 33 shown in FIG. 1, the intended purpose is achieved by at least the first cleaning jig 31, and preferably the second cleaning jig is used. Three
2 or 33 are provided.

The first cleaning jig 31 is attached to the electrode holder 4 and set in the magazine pot 212 of the magazine 21 in advance and used, like the electrode EL for fine hole machining for replacement. Further, the second cleaning jig 32 or 33 is directly or indirectly fixed to the table 121 in the vicinity of the workpiece so as to be detachable. FIG. 1 shows a state in which the cleaning jig 32 and the cleaning jig 33 are horizontally attached to the surface plate 13.

The cleaning jig 31 includes the holder 4 and the spindle device 1.
6 and is inserted into the guide hole of the electrode guide 17 while rotating. Then, when the guide hole is penetrated, the processing waste of the guide hole is scraped to the outside. In addition, the cleaning jig 32 or the cleaning jig 33 has a predetermined pressure in the guide hole of the electrode guide 17 after the electrode guide 17 is positioned so that the openings of the nozzles and the guide holes of the electrode guide 17 are substantially aligned. The fluid is jetted and supplied.

FIG. 2 shows an embodiment of the first cleaning jig in the small hole electric discharge machine of the present invention. The electrode guide portion basically includes an electrode guide 17 and a guide base 18 that supports the electrode guide 17. The small hole electric discharge machine of this embodiment is provided with an auxiliary guide 19.

The electrode guide 17 includes a guide body 171 and
A guide holder 172 for holding the guide body 171 is provided. The guide body 171 is provided with a guide hole 173 having an inner diameter obtained by adding a slight clearance of tens of μm or less to the diameter of the fine hole machining electrode EL to be used. And rotatably guides the fine hole machining electrode EL.

The electrode guide 17 is fitted to a guide base 18 fixed to the tip of the supporting arm member 166. The guide base 18 includes an upper base body 181 that supports the auxiliary guide 19 and a lower base body 1 that supports the electrode guide 17.
82, but if the auxiliary guide 19 is not provided or the electrode guide 17 and the auxiliary guide 19 are integrated, they are formed of one base material.

Like the electrode guide 17, the auxiliary guide 19 is fitted to the guide base 18. Auxiliary guide 1
Reference numeral 9 is for guiding the tip portion of the fine hole machining electrode EL to the guide hole 173 of the electrode guide body 171 having a small inner diameter to facilitate insertion of the fine hole machining electrode EL into the guide hole 173. -Shaped introduction hole 191 is formed.

The electrode holder 4 holds the electrode EL for fine hole processing. The electrode holder 4 holds the fine hole machining electrode EL by rotating the fastening tool 41 and tightening the collet (not shown) inside with a pressure that does not crush the fine hole machining electrode EL. When removing the fine hole machining electrode EL, the fastener 41 is rotated in the opposite direction to loosen the collet. A machining liquid supply path is formed inside the electrode holder 4,
When the fine hole machining electrode EL is a pipe electrode, a high-pressure machining liquid from the machining liquid supply device 6 shown in FIG. 5 is supplied into the hollow hole of the pipe electrode. When the electrode holder 4 holds the fine hole machining electrode EL, the electrode holder 4 and the fine hole machining electrode EL are liquid-sealed to the extent that they can withstand a high-pressure machining liquid.

The first cleaning jig 31 includes a pin 311. The pin 311 is a hard and tough member obtained by molding a hard material such as tungsten or a piano wire into a small diameter. The pin 311 is preferably a needle-like member whose tip is tapered so that it can be easily inserted into the narrowing guide hole 173. Pin 3
The outer diameter of 11 is slightly smaller than the guide hole 173 of the electrode guide 17, and is slightly larger than the outer diameter of the fine hole machining electrode EL. The length of the pin 311 is slightly longer than the sum of the guide hole 173 of the guide body 171, the introduction hole 191 of the auxiliary guide 19, and the distance between the guide body 171 and the auxiliary guide 173. It need not be any more.

The pin 311 is attached to the electrode holder 4 in the same manner as the fine hole machining electrode EL, and together with the electrode holder 4 to which another fine hole machining electrode EL for replacement is attached, a pin of the magazine 21. It is set in the magazine pot 212. Therefore, when cleaning the electrode guide 17, the cleaning jig 31 is mounted on the spindle device 16 by the automatic electrode exchanging device 2 in the same manner as the fine hole machining electrode EL.

As described above, the first cleaning jig of the present invention is
The pin has an excellent structure for cleaning the guide hole of the electrode guide. It can be inserted into the guide hole without bending, withstands repeated reciprocating movements, and effectively removes machining chips in the guide hole. You can Then, it is possible to secure a route in the guide hole through which the fine hole machining electrode can be easily inserted.

The first cleaning jig 31 mounted on the spindle device 16 is inserted into the guide hole 173 of the electrode guide 17 as the machining spindle 161 moves up and down while rotating, penetrates the guide hole 173, and is pulled out. At least 1
The machining waste in the guide hole 173 is scraped out by performing the "reciprocating motion" once. The number of times of this reciprocating motion is set by the setting device. In this embodiment, since the cleaning jig is inserted directly into the guide hole of the guide body while rotating and reciprocates to scrape out the processing waste, even if the processing waste is a little strongly attached, the cleaning jig is washed with a fluid of a predetermined pressure. The machining debris can be removed from the guide hole much more reliably than the above. As a result, it is possible to secure a diameter of the guide hole sufficient for inserting the fine hole machining electrode EL without the operator's hand.

The pin 3 of the first cleaning jig 3 described above
No. 11 is currently difficult to manufacture if the outer diameter is less than 0.1 mm, and can be cleaned with the tool electrode EL without using the pin 311 if the outer diameter exceeds 0.3 mm. Therefore, it is most effective that the pin 311 has an outer diameter corresponding to the fine hole machining electrode EL of φ0.1 mm to φ0.3 mm. In this embodiment, a tungsten rod with a diameter of 0.1 mm is used to obtain good results.

FIG. 3 shows an embodiment of a second cleaning jig used in the small hole electric discharge machining apparatus of the present invention. The detailed configurations of the first cleaning jig 31, the electrode guide 17, and the electrode holder 4 shown in FIG. 3 are basically the same as those of the first cleaning jig 31, the electrode guide described in FIG. 17 and the electrode holder 4 are the same as each other, and a detailed description thereof will be omitted.

The cleaning jig 32 is an application of a machining liquid jet device for supplying a jet of machining liquid to the machining gap. The cleaning jig 32 includes a nozzle 321, a member 322 that fixes one end of the nozzle 321, and a fixing member that introduces the working liquid sent from the working liquid supply device 6 into the nozzle and fixes the working liquid on the surface plate 13. 323 is included. Nozzle 321
The nozzle 321 can be freely bent, and the bent state can be maintained as it is.

The second cleaning jig 32 is the first cleaning jig 3
When scraping the processing scraps from the guide hole 173 of the electrode guide 17 with 1 to clean, a fluid of a predetermined pressure is applied to the electrode guide 17
Is sprayed and supplied to the end surface GS (lower end surface) of the above to clean the lower end surface GS. Specifically, the pin 31 of the first cleaning jig 31
When 1 passes through the guide hole 173, a fluid having a predetermined pressure is jetted and supplied to the lower end surface GS.

In this embodiment, the fluid having a predetermined pressure for cleaning the lower end surface GS of the electrode guide 17 which is jetted and supplied from the nozzle 321 is practically an electric discharge machining fluid which does not affect the machining gap. Is. The pressure of the working fluid is equal to or lower than the pressure of the working fluid supplied from the pipe electrode in the small hole electric discharge machining. In addition, preferably, as shown in this embodiment, a guard 34 for receiving liquid droplets scattered by supplying a jet stream of a high-pressure working liquid is provided.

The second cleaning jig 32 not only displaces the guide holes 173 of the electrode guide 17 but also the processing chips adhering to the lower end surface GS widely and evenly. Since the cleaning is performed before the fixing, and especially the processing scraps attached to the lower end surface GS of the electrode guide 17 are removed,
There is an advantage that the cleaning effect of the electrode guide 17 is enhanced. Therefore, basically, the second cleaning jig 32 is used together with the first cleaning jig 31. Further, at this time, the second cleaning jig 32 has a function of blowing off the processing waste scraped out by the first cleaning jig 31 and washing it away with the processing waste attached to the lower end surface GS of the electrode guide 17. In addition, a high cleaning effect can be obtained.

Second cleaning jig 3 in this embodiment
No. 2 has the advantage that the area in which this type of cleaning jig can be installed is wide because the direction of the nozzle's injection port can be changed arbitrarily. Further, there is an advantage that a machining liquid jet supply device having a nozzle for supplying a jet of the machining liquid to the machining gap can be applied.

FIG. 4 shows another embodiment of the second cleaning jig used in the small hole electric discharge machining apparatus of the present invention. The detailed configurations of the first cleaning jig 31, the electrode guide 17, and the electrode holder 4 shown in FIG. 4 are basically the same as those of the first cleaning jig 31, the electrode guide described in FIG. 17 and the electrode holder 4 are the same as each other, and a detailed description thereof will be omitted. Further, unless otherwise specified, the action and effect in cleaning are the same as those of the second cleaning jig 32.

The second cleaning jig 33 includes a nozzle 331,
The fluid supply block member 332 and the fixing member 333 are included. The nozzle 331 has a hollow hole 33 penetrating in the length direction.
4 and the opening of the hollow hole 334 of the electrode guide 17
Is an ejection port of a nozzle 331 for ejecting a fluid for cleaning. When performing the "cleaning operation", the workpiece WP
Lower end surface GS of the electrode guide 17 facing the processed surface WS of
The electrode guide 17 is positioned such that the opening of the hollow hole 334 is arranged toward the.

The inner diameter of the nozzle 331, that is, the hollow hole 33.
The diameter of 4 may be a size that can secure a flow rate necessary and sufficient for the jetting of the machining fluid of a predetermined relatively high pressure to be jetted in an amount suitable for cleaning the electrode guide 17. Preferably, as shown in this embodiment, the tip end of the nozzle 331 having the ejection port is formed in a saucer shape that exactly matches the lower end surface GS of the guide body 171. According to this structure, the jet flow of the high-pressure working fluid is widely and uniformly ejected not only on the guide hole 173 of the electrode guide 17 but also on the lower end surface GS of the electrode guide 17 around the ejection port of the nozzle 331. The processing waste adhering to the end surface GS can also be flushed away as shown by the arrow in FIG.

The fluid supply block member 332 has a hollow supply passage (not shown) inside, and supplies the machining fluid of a predetermined pressure sent from the machining fluid supply device 6 shown in FIG. 5 through the flexible hose 335. It is introduced from an inlet provided at one side surface and introduced into the hollow hole 334.

As the fixing member 333, the cleaning jig 33 is mounted on the platen 1.
3 is a member to be detachably installed. In this embodiment, the fixing member 333 is a so-called magnet chuck, and the cleaning jig 33 is made to be attracted to the metal surface plate 13 to be adsorbed.
To fix. If the surface plate 13 is of a type such as ceramics that does not attract magnets, the table 1 in the processing tank 15
It can also be attached to another metal member having a horizontal surface other than the surface plate 13 on 21. In any case, the cleaning jig 33 needs to be erected so that the ejection port of the nozzle 331 faces the guide hole 173 of the electrode guide 17. Of course, if the fixing member 333 has another mounting structure such as a clamp, the material of the member at the mounting position need not be metal.

In the second cleaning jig 33, not only the guide hole 173 of the electrode guide 17 but also the machining waste adhering to the lower end surface GS is widely and evenly washed away. Since the cleaning is performed before the fixing, and especially the processing scraps attached to the lower end surface GS of the electrode guide 17 are removed,
There is an advantage that the cleaning effect of the electrode guide 17 is further enhanced.

The "cleaning operation" described above, that is, the rotation and reciprocating motion of the first cleaning jig 31 and the liquid supply operation of the second cleaning jig 32 or 33 in addition to this Every time the fine hole machining electrode EL is replaced due to consumption, it is carried out periodically. For example, a fine hole electric discharge machining of a cemented carbide with a plate thickness of 1.3 mm is performed with a fine hole machining electrode of φ0.1 mm, and about 100 fine holes are formed with one fine hole electric discharge machining electrode. While replacing the electrode for hole electrical discharge machining,
When cleaning the electrode guide with the cleaning jig of
It was confirmed that clogging of the guide hole could be sufficiently prevented.

FIG. 5 is a block diagram showing a control system centering on the control device of the small hole electric discharge machining apparatus of the present invention. The operation of automatically cleaning the electrode guide in the small hole electric discharge machining apparatus of the present invention will be described below with reference to FIG. The cross table 12 (relative moving device) shown in FIG. 5 includes a drive control device that drives and controls the servo motors 12X and 12Y, and the main spindle device 16 includes a machining main spindle 161, a slider 164, and a rotating device (not shown). It includes a drive control device that drives and controls each motor to be operated. In addition, the automatic electrode exchange device 2 is the magazine table 2
It includes a drive control device that drives and controls a motor that rotates 11 and an actuator 223 that operates the transfer device 22. Similarly, the machining liquid supply device 6 includes a drive control device that drives and controls a pump and a solenoid valve.

The control device 5 of this embodiment is a device that outputs signals for controlling the cross table 12, the spindle device 16, the automatic electrode changing device 2, and the machining liquid supply device 6, respectively. The control device 5 operates these devices according to an operator's instruction input from an operation panel (not shown), a signal input from the time measuring device 8, or a sequence program stored in the storage device 51 in advance. When the numerical control device is provided in parallel with the small hole electrical discharge machining device, the control device 5 can receive the signal sent from the numerical control device and control each of the above devices according to the NC program.

When cleaning the electrode guide 17, the control device 5 uses the first cleaning jig 31 housed in the magazine 21.
Attach the electrode holder 4 attached with to the spindle device 16,
When the electrode guide 17 has been cleaned, the automatic electrode exchanging device 2 is operated so that the electrode holder 4 with the cleaning jig 31 attached thereto is removed from the spindle device 16 and stored in the original predetermined location of the magazine 21. . And the control device 5
Inserts the cleaning jig 31 into the guide hole 173 of the electrode guide 17 and operates the spindle device 16 to reciprocate.

Further, when cleaning the electrode guide 17, the controller 5 positions the cross table 12 so that the second cleaning jig 32 or 33 attached to the surface plate 13 is located directly below the electrode guide 17. The table 121 is moved to a predetermined position by operating the slider 164 of the main spindle device 16 so that the lower end surface GS of the guide body 171 of the electrode guide 17 approaches the nozzle of the cleaning jig. The machining fluid having a predetermined pressure that is jetted and supplied is jetted into the guide hole 173 of the electrode guide 17.

The machining liquid supply device 6 supplies the stored machining liquid to the electrode EL for fine hole machining and the cleaning jig 3 with a predetermined pressure by a pump to collect the used machining liquid and purify it. The setting device 7 sets the number of reciprocating operations of the first cleaning jig 31 or the time for ejecting the liquid of a predetermined pressure from the second cleaning jig 32 or 33. Time measuring device 8
Is a timer circuit or a clock counter for measuring the time for which a liquid having a predetermined pressure is jetted to the electrode guide 17 to wash it.

Next, the operation of automatically cleaning the electrode guide in the small hole electric discharge machining apparatus of the present invention will be described more concretely with some examples. The storage device 51 stores a sequence program of a cleaning operation that is regularly performed in advance. The data stored in the storage device 51 includes the magazine 21 of the automatic electrode replacement device 2.
The tool number of the magazine pot 212 in which the first cleaning jig 31 is set is included.

[First Sequence] The first sequence is an example of cleaning the electrode guide 17 using the first cleaning jig 31 including the pins 311.

The spindle device 16 is moved to a predetermined position where the fine hole machining electrode EL is automatically replaced. The electrode holder 4 to which the fine hole machining electrode EL mounted on the spindle device 16 is attached is removed from the automatic electrode exchanging device 2 and is stored in the empty magazine pot 212. Based on the number data of the magazine pot 212 stored in the storage device 51 in advance, the automatic electrode exchanging device 2 is caused to take out the electrode holder 4 to which the cleaning jig 31 is attached from the magazine pot 212 of the predetermined number, and the main shaft is rotated. It is attached to the device 16. The machining spindle 161 of the spindle device 16 is rotated and moved in the direction of the electrode guide 17, and the tip of the pin 311 of the cleaning jig 31 is introduced from the introduction hole 191 to the guide hole 1.
73 and insert the pin 311 while rotating it. While the machining spindle 161 of the spindle device 16 is rotated, the pin 311 is set a predetermined number of times by the setting device 7,
For example, the guide hole 173 is reciprocated so as to reciprocate 10 times. If the set number of times is 1, the reciprocating motion is terminated by pulling out the pin 311 that has been penetrated. The machining spindle 161 of the spindle device 16 is raised to pull out the pin 311 from the guide hole 173, move the electrode for fine hole machining EL to a predetermined position for automatic replacement, and stop the rotation of the machining spindle 161. The electrode holder 4 to which the cleaning jig 31 attached to the spindle device 16 is attached is detached from the automatic electrode exchanging device 2 and returned to the magazine pot 212 of a predetermined number. Based on the data of the number of the magazine pot 212 storing the electrode holder 4 with the new small hole machining electrode EL stored in the storage device 51, the automatic electrode exchanging device 2 is provided with new small hole machining from the magazine pot 212. Electrode EL
The electrode holder 4 with the attached
To be attached to.

[Second Sequence] The second sequence is an example of cleaning the electrode guide 17 using the second cleaning jig 32 or 33. The same operation as the first sequence described above will be briefly described.

[] -In the first sequence
Execute []. The cross table 12 and the slider 164 of the spindle device 16 are moved to bring the guide body 171 of the electrode guide 17 close to immediately above the second cleaning jig 32. The spindle device 16 is moved in the direction of the electrode guide 17, and the tip of the pin 311 of the first cleaning jig is rotated and inserted into the guide hole 173 from the insertion hole 191 and penetrated.
The spindle device 16 is moved so that the pin 311 reciprocates within the guide hole 173 a predetermined number of times. The machining spindle 161 of the spindle device 16 is raised and the pin 311 is pulled out from the guide hole 173. In parallel with the operations of [] and [], the time measuring device 8 is turned on and the pump of the machining liquid supply device 6 is driven to jet and supply a jet of machining liquid of a predetermined pressure from the second cleaning jig. To do. After the set time, the pump of the working fluid supply device 6 is stopped based on the signal input from the time measuring device 8. The cross table 12 and the machining spindle 161 of the spindle device 16 and the slider 164 are moved to return the electrode guide 17 to the initial position, and the spindle device 16 is moved to a predetermined position for automatic electrode replacement and rotation is stopped. [] And [] in the first sequence are executed.

The small hole electric discharge machining apparatus of the present invention described above can be appropriately modified without departing from the technical idea of the present invention. For example, the configuration of this machine of the small hole electrical discharge machining apparatus is not limited to the configuration shown in the embodiment as long as it operates substantially the same. Also, for example, the second
The timing of supplying and stopping the fluid having a predetermined pressure of the cleaning jig can be variously modified regardless of time such as synchronizing with the operation of the first cleaning jig.

[0061]

By implementing the small hole electric discharge machining apparatus of the present invention, even when a large number of small holes are continuously electric discharge machined, the electrode guide is clogged and the small hole machining electrodes are replaced. It is prevented that you cannot do it. As a result, there is less risk of interruption of processing due to clogging of the electrode guide,
More stable long-term continuous automatic operation in small hole electrical discharge machining becomes possible. Further, the electrode guide can be automatically cleaned effectively, and the burden on the operator can be greatly reduced without bothering the operator.

In addition, since the fine hole electric discharge machining apparatus of the present invention is sufficient if the cleaning jig is set on the magazine pot or on the surface plate outside the machining range, it is an obstacle when moving the machining position during electric discharge machining. do not become. In addition, since the automatic electrode replacement device is used, it is not necessary to newly install a device for cleaning a large-scale special electrode guide, and the electrode guide can be effectively used in the small hole electric discharge machine equipped with the existing automatic electrode replacement device. It has an excellent effect that it can be cleaned.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic configuration of a main unit of a small hole electric discharge machining apparatus of the present invention.

FIG. 2 is a diagram showing an embodiment of a small hole electric discharge machining apparatus and an embodiment of a jig for cleaning an electrode guide according to the present invention.

FIG. 3 is a view showing another embodiment of the small hole electric discharge machining apparatus and another embodiment of a jig for cleaning another electrode guide of the present invention.

FIG. 4 is a view showing an embodiment of cleaning another electrode guide of the present invention.

FIG. 5 is a block diagram showing a control device of the small hole electric discharge machining apparatus of the present invention.

[Explanation of symbols]

1, this machine 12, cross table (relative movement device) 121, table 13, surface plate 14, column 16, Spindle device 161, processing spindle 162, chuck 164, slider 17, electrode guide 2, automatic electrode changer 21, magazine 211, magazine table 212, magazine pot 22, transfer device 3, cleaning jig 31, first cleaning jig 32, 33, second cleaning jig 4, electrode holder EL, electrode for fine hole processing WP, work piece

Claims (5)

[Claims] 1. A machining spindle for gripping a fine hole machining electrode via an electrode holder and descending while rotating the fine hole machining electrode with respect to a workpiece to perform electrical discharge machining of the workpiece.
An electrode guide device for raising and lowering by having a guide hole for rotatably and vertically elevating the fine hole machining electrode, and a fine hole machining electrode which is housed in advance and which has a desired fine hole machining electrode. In the small hole electric discharge machining apparatus including an automatic tool exchanging device which is transferred and attached to and detached from the electric tool exchanging device, the automatic tool exchanging device attaches a pin having a diameter substantially matching a diameter of the fine hole machining electrode to the electrode holder. The cleaning jig is stored in the first cleaning jig, the cleaning electrode holder is transferred to the machining spindle at predetermined intervals, and the machining spindle rotates the pin of the cleaning electrode holder. A small-hole electric discharge machining device characterized in that the guide hole is cleaned by inserting the electrode guide device into the guide hole and moving up and down. 2. The fine hole electric discharge machining apparatus according to claim 1, wherein a predetermined cycle of cleaning the electrode guide hole by the pin is performed every time the fine hole machining electrode is replaced. 3. The diameter of the fine hole machining electrode is 0.1 m.
The small hole electrical discharge machine according to claim 1, wherein the small hole electrical discharge machine is m to 0.3 mm. 4. A second cleaning jig, which is a nozzle device for jetting a machining liquid into the guide hole of the electrode guide, is placed near the workpiece, and when the pin cleans the guide hole. The machining spindle and the guide device are moved so that the pin and the electrode guide are positioned directly above the nozzle device, and the nozzle device sprays a machining liquid onto the guide hole. The small hole electric discharge machine described. 5. The small hole electric discharge machining apparatus according to claim 4, wherein the nozzle device includes a nozzle having an upper end surface that substantially matches the shape of the lower end surface of the electrode guide.