JPS61100323A - Electrode holder for electrical discharge machining - Google Patents

Abstract

PURPOSE:To reduce abnormal sparks and accumulation of chips, by providing, in an electrode holder, a rotary blade member rotating substantially concentric with the center axis of an electrode so that a machined surface is cleaned by agitated stream of machining liquid around the electrode. CONSTITUTION:A water wheel section 19d is formed in the outer periphery of a rotary blade member 19 disposed in an electrode holder 12 holding an electrode 10 for electrical discharging machining, and an injection nozzle 22 for energizing and rotating the water wheel section 19d is integrally incorporated with the holder 12. A predetermined electrical discharge machining process is carried out such that the spindle of the electrical discharge machining device is lowered to make the electrode 10 approach a workpiece 24 in machining liquid 23. At this time the machining liquid is jetted toward the water wheel section 19d to energize and rotate the rotary blade member 19. Then, the blade section 19c offers the stream of machining liquid which directs downward, and therefore, the machining liquid is agitated. This agitation is effected to all machining liquid 23 surrounding around the electrode 10 as indicated by the chain line. Accordingly, a satisfactory electrical discharge may be made entirely of a section to be machined.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electrode holder for holding an electrode for electrical discharge machining.

[Conventional technology]

Conventionally, an electrode 1 for electrical discharge machining of this type was fixed to the tip of an electrode mounting shank 2, as shown in FIG. 6, and was held in an electrode holder 3 via the electrode mounting shank 2. Then, the workpiece 4 to be electrically discharged is mounted and fixed on the head 5 of the electrical discharge machine, the electrode holder 3 is attached to the main shaft 6 of the electrical discharge machine, and the workpiece 4 is moved by lowering the main shaft 6 at a predetermined speed. Machining is performed by an electric discharge phenomenon between the electrode 1 and the electrode 1. At this time, chips of the work 4 and gas are generated between the work 4 and the electrode 1 due to electric discharge, so the tip of the flexible nozzle 7 fixed at one end of the bed 5 is used to machine the work 4 and the electrode 1. The liquid 8 was injected in an attempt to discharge the chips and the like.

[Problem that the invention seeks to solve]

In such a conventional device, since the machining fluid 8 is injected from the tip of the flexible nozzle 7 onto only a portion of the electrical discharge machining portion, the machining fluid 8 may not be discharged and may accumulate in other portions. , the machining speed may decrease, or an abnormal arc may occur, causing partial wear of the electrode 1.
Work 4 could be made defective. In addition, in order to solve these problems, we applied machining fluid 8 to the entire electrical discharge machining part.
A plurality of flexible nozzles 7 for spraying the liquid were arranged around the workpiece 4. However, it is also necessary to pipe a hose for supplying the machining fluid 8 to each flexible nozzle 7, which is a complicated and time-consuming process, and even with such means, the machining fluid 8 can only be sprayed partially. Good electrical discharge machining was not obtained. Furthermore, in an electric discharge machine using an automatic electrode exchange device that automatically exchanges different types of electrodes 1 for long-term unattended operation, it is difficult to However, there have been problems such as the inability to inject the machining fluid 8 to certain parts.

[Features of the invention]

The present invention provides processing in which a rotary blade member having a water wheel portion that rotates approximately concentrically with the axial center line of the electrode is disposed on an electrode holder that holds an electrode for electric discharge machining, and the water wheel portion is injected from an injection nozzle. The purpose is to rotate the rotary vane member by rotationally biasing it with the liquid, and to stir the machining liquid around the electrode by the rotation of the rotary vane member.

〔Example〕

1 and 2 show an embodiment of the present invention, in which an electrode 10 for electrical discharge machining is fixed to the end face of a cylindrical electrode mounting shank 11 by brazing or the like. The proximal end side is held in an electrode holder 12. The electrode holder 12 has a mounting portion 12a shown in the upper part attached to the main shaft 13 of the electrical discharge machine.

Further, the electrode holder 12 is provided with a center hole 12b that coincides with the center axis, and a holding cylinder 14 whose inner diameter is slightly larger than the outer diameter of the electrode mounting shank 11 is disposed in the center hole 12b. . The portion of this holding cylinder 14 that holds the electrode mounting shank 11 is formed thin, and hydraulic oil 15 is sealed in this thin portion. By turning a screw 16 provided on the circumferential surface of the electrode holder 12, a piston 17 interlocked with this screw 16 causes oil 15 to be removed.
Since the enclosed volume of the electrode mounting shank 1 becomes smaller, the thinner part of the holding cylinder 14 acts to bend in the central axis direction.
1 is kept tightened from all around. Further, the electrode mounting shank 11 and the one-electrode holder 12 are positioned by abutting a positioning pin lla implanted on the end surface of the electrode holder 12 on the electrode 10 side.

The electrode holder 12 having such a structure has a cup portion 12c that is open at the bottom and extends integrally around the outer periphery of the electrode holder 12. A rotating blade member 19 that rotates concentrically with the axial center line of the electrode 10 is disposed inside the cup portion 12c. This rotating blade member 19 has an inner ring part 19a and an outer ring part 1 as shown in FIG.
A plurality of blades 19c are integrally formed in an inclined manner between the outer ring portion 19b and a water wheel portion 19d. The inner ring portion 19a is the electrode holder 1.
It is loosely fitted into the shaft portion 12d located within the cup portion 12c of No. 2, and is rotatably held by a large number of balls 21 interposed between the shaft portion 12d and the presser plate 20.

On the other hand, a nozzle 22 inclined with respect to the radial direction is installed on the peripheral wall of the cup portion 12c facing the water wheel portion 19d, as shown in FIG. This nozzle 22 is connected via a hose to a well-known pump (not shown), and the rotary blade member 19 is urged to rotate by injecting machining fluid 23 from the nozzle 22 toward the water wheel portion 19d. The machining fluid 23 injected from the nozzle 22 in this manner is stored in a water tank provided in an electrical discharge machine (not shown) at least at the water level shown in FIG. 1, and is returned to the pump via the filter device.

Here, reference numeral 12e in the figure indicates a plurality of punch holes formed to exhaust air accumulated in the cup portion 12c at the time of startup and to exhaust gas generated during electrical discharge machining.

FIG. 3 shows a modification of FIG. 1, in which a rotary vane unit 25 is detachably attached to the body of the electrode holder 12 on the electrode side. That is, inside the approximately cup-shaped rotary vane unit 25, a rotary vane member 26 having a water wheel portion formed on its outer periphery is rotatably supported by a bearing tube 27 provided at the center, similar to the above-described example. Further, the rotary vane unit 25 has a mounting cylinder part 25a formed at the upper part thereof, and the mounting cylinder part 25a is inserted into the body of the electrode holder 12 and attached with fixing screws 28. Then, by injecting the machining liquid from the nozzle 29 provided on the outer periphery, the rotating blade member 26 is
is rotated to stir the machining fluid around the electrode (not shown).

This rotary vane unit 25 can be used by being attached to a conventional electrode holder 3.

FIG. 4 shows another embodiment, in which a rotating blade member and the like are constructed in a female coupling type electrode holder that directly holds an electrode. That is, on the upper surface of the electrode holder 30, there is a mounting part 33 for mounting on a male coupling 40, which will be described later, which is positioned and mounted on the main shaft 31 of the electrical discharge machine.
is formed. The mounting portion 33 has a V-shaped groove 33a formed in a cross shape at right angles, and an engagement hole 33b formed in the center of the V-shaped groove 33a. Also,
The V-shaped groove 33a is arranged so as to communicate with the inside of the retaining hole 33b.
A through hole 33c is formed at an angle of 45 degrees with respect to the direction of the groove, through which an eccentric pin 34, which will be described later, is inserted. Further, a cup portion 35 extends around the lower part of the mounting portion 33 . A shaft portion 36 that is coaxial with the engagement hole 33b of the mounting portion 33 is integrally formed in the center of the cup portion 35, and a holding plate 37 for holding the electrode 10 on the lower end surface of the shaft portion 36.
are fixed with screws 38. Inside the cup portion 35, a rotary blade member 19 having a water portion 9d formed thereon is rotatably held as in the example shown in FIG. The rotation is urged by the machining fluid 23 injected from 39.

The electrode holder 30 having such a configuration is attached to a male coupling 40 as shown in FIG. 5, for example. The male coupling 40 has an electrode holder 30 on the lower surface in the figure.
The four ■-shaped recesses 40a that fit into the V-shaped grooves 33a of
A tightening portion 40b that is inserted into the main shaft 31 is provided protrudingly and is inserted into the main shaft 31.
A mounting hole 40c is drilled through which a bolt (not shown) for mounting is inserted.

Further, the tightening portion 40b has a locking hole 40d perpendicular to the axial direction.
are drilled, each of the seven-shaped grooves 33a of the electrode holder 30 is engaged with the ■-shaped cavity 40a of the male coupling 40, and the eccentric pin 34 is inserted into the engagement hole 33b with the tightening part 40b inserted. The through hole 33c of the electrode holder 30 and the locking hole 4
If it is rotated after being inserted through 0d, the cam action of the eccentric pin 34 pulls it toward the male coupling 40 and they are coupled together.

On the other hand, when the electrode holder 30 is used in an automatic electrode changing device (not shown) of an N/C electrical discharge machine, first the retaining hole 33b of the electrode holder 30 is Connecting rod 41 is attached to using eccentric pin 34. And this connecting rod 4
An arm 42 having a flushing hole 42a that is coupled to the nozzle hole 39 and supplies the machining fluid 23 when the electrode 1 is clamped to the clamper of the electrode automatic exchange apparatus is integrally disposed on the electrode automatic exchange apparatus. There is.

[Effect]

Next, the operation of the present invention described above will be explained based on FIG. First, the electrode 10, which has been molded into a desired shape, is held in position on the electrode holder 12 via the electrode attachment shank 11. Then, the main shaft of the electrical discharge machine is lowered to bring the electrode 10 close to the workpiece 24 in the machining fluid 23 attached to a bed or the like, and electrical discharge machining is performed at a predetermined speed. At this time, from the nozzle 22 installed on the peripheral wall of the cup Ci+i2c, the machining fluid 23 pumped by a pump (not shown) is injected toward the water wheel portion 19d, and the rotating blade member 19 is urged to rotate. ° When this rotary blade member 19 rotates, the machining fluid 2 is heated by the plural blades 19c.
3 is stirred by a water flow directed downward in the figure. This agitation occurs because the rotating blade member 19 rotates approximately concentrically with the axial center line of the electrode 10, so that the agitation water flow covers the entire periphery of the electrode 10 that is performing electrical discharge machining on the workpiece 24, as shown by the dotted line. The processing liquid 23 is intensively stirred. For this reason, chips and gas generated from the work 24 due to discharge are scattered,
Machining fluid 23 is supplied from another location between the electrode 10 and the workpiece 24, and good electrical discharge is performed in the entire electrical discharge machining area.

The above-mentioned effect is the same in the example shown in FIG.

〔Effect of the invention〕

According to the present invention as described above, since the rotating blade member that rotates approximately concentrically with the axial center line of the electrode is disposed in the electrode holder, the rotary blade member that rotates approximately concentrically with the axial center line of the electrode is arranged, so that the rotary blade member that rotates approximately concentrically with the axial center line of the electrode is disposed. Since the gas is scattered over the entire surface and cleans the electrical discharge machining surface, abnormal arcs and chip accumulation are reduced, and the entire surface can be electrically discharged satisfactorily without decreasing the machining speed. Furthermore, since the rotating blade member is rotated and urged by spraying machining fluid, the same equipment as before can be used.
Furthermore, since a special rotating device and a large number of hose piping are not required, the structure can be extremely inexpensive. In addition, since the rotating blade member generates an agitating water flow, even if the shape or size of the electrode changes, there is no need to move the nozzle each time, unlike conventional methods, and when performing unmanned automatic operation using an automatic electrode exchange device. suitable for

[Brief explanation of drawings]

1 to 5 show one embodiment of the present invention, in which FIG. 1 is a partially cutaway side sectional view, FIG. 2 is a sectional plan view of the main part, and FIG.
The figure is an exploded side view showing a modified example of Fig. 1, Fig. 4 is a partially cutaway sectional view showing another embodiment, Fig. 5 is a perspective view showing a male coupling, and Fig. 6 shows a conventional example. FIG. 10-・Electrode 11-111 Electrode mounting shank 12.
30-electrode holder 12c, 35-cup part 12
d, 36-Shaft part 13...Main shaft 19-Rotating blade member 19c...Blade 19d--Water wheel part 22.39
~ Nozzle patent applicant Katsuhiro Yoshie Figure 1 Figure 2 Figure 5

Claims (1)

[Claims] A rotary blade member that rotates approximately concentrically with the axial center line of the electrode is disposed on an electrode holder that holds an electrode for electric discharge machining, and a water wheel portion is formed on the outer peripheral side of the rotary blade member,
Electrical discharge machining characterized in that an injection nozzle for rotationally biasing the water wheel section by injection of machining fluid is provided integrally with the electrode holder, and the machining fluid around the electrode is agitated by rotation of the rotary blade member. electrode holder.