JP2565680B2 - Perforation electric discharge machining attachment - Google Patents

Description

TECHNICAL FIELD The present invention relates to an attachment for perforation electric discharge machining.

[Conventional technology]

The electric discharge machining apparatus supplies a machining fluid from a machining fluid injection nozzle between a workpiece and an electrode and applies an intermittent voltage pulse to perform non-contact machining by utilizing an electric discharge phenomenon generated at that time. It is a thing.

In this type of electric discharge machining device, a long or narrow pipe-shaped copper or copper-based alloy electrode is used for the electrode, and a machining liquid is supplied through the inside of the pipe-shaped electrode, and the hole diameter is about 0.1 mm to 5 mm, The workpiece may be subjected to perforation electric discharge machining having a depth or length of at least about 5 times the hole diameter.

However, in the perforation electric discharge machining with the pipe-shaped electrode, since a thin and long pipe-shaped electrode of, for example, about 500 mm is used, if electricity is applied to the electrode from the chuck part of the electrode end, etc., the electric discharge circuit The resistance value may be large or may increase, and due to such an increase in the resistance value of the discharge circuit, various serious machining is performed by heating the pipe-shaped electrode and the working fluid supplied under pressure through the inside thereof. Not only does it cause trouble, but the resistance of the discharge circuit and the floating reactance value may change due to wear of the pipe-shaped electrode.
Ip decreases, discharge pulse time τon and rest time τoff
However, there is a problem that the processing state becomes unstable due to changes in the relationship such as the waveform.

[Problems to be solved by the invention]

The present invention has been made to solve the above problems, and an object of the present invention is to provide a pipe-shaped electrode due to an increase in discharge circuit resistance value in drilling electric discharge machining using a long pipe-shaped electrode. Of the discharge current crest value Ip due to changes in the reactance value of the discharge circuit, preventing problems that lead to various processing obstacles such as the heating of and the heating of the machining fluid supplied through it. An object of the present invention is to provide a novel attachment for electric discharge machining capable of preventing the discharge voltage and the current waveform from changing more than a predetermined limit and performing the electric discharge machining with high accuracy in a stable electric discharge machining state.

[Means for solving problems]

Thus, the above-mentioned object is provided with a guide passage through which the pipe-shaped electrode is inserted, and a pipe for sucking the working fluid which is supplied through the inside of the pipe-shaped electrode and is jetted from the tip end. The main body portion, which is the tip portion of the electrode and is disposed in the vicinity of the surface of the workpiece, and the pipe-shaped electrode, which is inserted through the main body portion and is in the guide path portion of the pipe-shaped electrode, is substantially perpendicular to the axial direction of the electrode And a conductive member attached to the main body so as to be able to come into and out of contact with the main body, and an elastic force in the perpendicular direction is applied to the conductive member to constantly press the inner end of the conductive member against the pipe-shaped electrode. The upper surface of the workpiece is usually provided with a spring that presses against the inner wall surface of the guide path on the side opposite to the side in contact with the current carrying member, and means for connecting the outer end side of the current carrying member to a power supply for electric discharge machining. Placed directly on or placed close enough It is achieved by drilling discharge machining attachment to be used.

[Action]

By configuring as described above, during drilling electric discharge machining with a pipe-shaped electrode, it is possible to prevent changes in the discharge circuit conditions such as an increase in the discharge circuit resistance value due to the use of the pipe-shaped electrode, and to prevent various machining failures. Stable perforation electric discharge machining can be performed without causing heating of the connected pipe-shaped electrode and the supplied machining liquid, and without changing the discharge current peak value Ip, the waveform of the discharge pulse time τon and the pause time τoff, and the like.

[Examples] Hereinafter, details of the present invention will be specifically described with reference to the drawings.

FIG. 1 is an explanatory view showing an embodiment of an attachment for punching electric discharge machining according to the present invention.

In FIG. 1, 1 is an attachment for perforating electric discharge machining according to the present invention, 2 is a main body portion thereof, 2a is a guide passage provided in the main body portion 2 for inserting a pipe-like electrode, and 2b is the main body. A suction pipe line for sucking and collecting the machining liquid provided in the part 2, 2c is a hole for conducting electricity provided in the main body part, 3 is a conducting hole, 4 is a spring, 5 is the above conducting hole 2c. , A special screw that has a male screw that meshes with a female screw that supports the electronic device 3 so that it can move back and forth, 6 is a working fluid recovery pipe attached to the suction pipe line, 7 is a pipe-shaped electrode, and 8 is the pipe. A chuck for attaching the shaped electrode 7, a workpiece 9, a power source 10 for electric discharge machining, a holding handle 11 for holding and supporting the main body 2, and the holding handle 11 is usually a chuck 8
It is fixed to a spindle holding processing head that holds the workpiece and feeds it. However, in some cases, it may be integrated with the fixed side of the workpiece 9 and may be used by being placed on the upper surface of the workpiece 9. is there.

Thus, the main body 2 is provided with a guide path 2a for inserting the pipe-shaped electrode 7 attached to the chuck 8 and is formed around the tip-processed portion 7a of the pipe-shaped electrode 7. A suction pipe line 2b is provided for collecting the machining liquid jetted and supplied from the concave portion to the machining gap through the pipe-shaped electrode 7. Further, the conduction electron 3 is inserted into the main body 2 to form a pipe shape. In the inner portion of the guide path 2a of the electrode 7, there is provided a through hole 2c for mounting so as to be capable of advancing and retracting so as to come into contact with the pipe-shaped electrode 7 from a direction substantially perpendicular to the axial direction of the electrode.

The conducting member 3 is made of a material such as gold, silver, copper, a current-carrying brush material, a contact material, etc., which has good current-carrying property and preferably wear resistance, and has a tip end portion on the side contacting the pipe-shaped electrode 7. It has a spherically rounded shape so that the pipe-shaped electrode 7 inserted from the guide passage 2a can easily pass therethrough, and its outer periphery is provided so that it can slide forward and backward through the hole 2c for conducting electrons. The other stepped shaft portion is slidably provided in the center hole of the special screw 5, and the stepped portion 3a and the special screw 5 are provided.
A spring 4 is provided between and, so that the conduction 3 is constantly pressed toward the pipe-shaped electrode 7, and the pipe-shaped electrode 7 is pressed against the inner surface of the guide path 2a facing the conduction 3 and positioned. To be done.

The electric power source 10 for electric discharge machining is wired so as to be electrically connected to the current-carrying electron 3 and the workpiece 9, and applies a discharge voltage pulse for machining between the pipe-shaped electrode 7 and the workpiece 9 via the current-carrying electron 3. Is configured.

The drilling electric discharge machining attachment 1 is placed at a position where the drilling electric discharge machining is performed on the workpiece 9 as described above, or directly attached to a predetermined position on the upper surface of the workpiece 9 by a holding handle 11 extended from a column or the like (not shown). It is designed to be fixed in a contact state or a sufficiently close position.

At the time of electric discharge machining, the attachment 1 for perforating electric discharge machining, which is a vital part of the work, is set at a predetermined machining position on the workpiece 9, and the pipe-shaped electrode 7 attached to the chuck 8 is guided to the guide path 2a. And is made to approach the object 9 to be processed. After that, the machining liquid is jetted and supplied to the machining portion between the pipe-shaped electrode 7 and the workpiece 9 through the electrode 7, the machining fluid is recovered through the suction pipe line 2b, and the electric power is supplied from the electric discharge machining power source 10. The electricity is applied to the pipe-shaped electrode 7 through the electron 3 in a stable state without any change during processing at a position of a certain distance on the surface of the work piece 9 for machining between the electrode and the work piece. An electric discharge voltage pulse is applied to perform perforation electric discharge machining on the workpiece 9.

Therefore, according to the attachment 1 for perforating electric discharge machining according to the present invention, the vertical positioning of the pipe electrode 7 can be performed easily and reliably, and the pipe-shaped electrode due to an increase in the resistance value of the electric discharge circuit during electric discharge machining. In addition, it is possible to perform stable drilling electric discharge machining by preventing changes in the conditions of the electric discharge circuit, such as by not heating the machining liquid supplied through the inside.

As for the change of the discharge circuit condition, when the plate thickness of the work piece 9 is 1000 mm or thick, even if the length change due to the wear of the electrode 7 during the work, the change occurs in the conventional energization method. However, according to the present invention described above, it is possible to surely perform the intended machining without changing the dimension of the machining hole, the machining feed rate, etc. due to such a change.

[Advantages of the Invention] Since the present invention is configured as described above, according to the present invention, during the perforation electric discharge machining with a long pipe-shaped electrode, an increase in the resistance value of the discharge circuit due to the use of the pipe-shaped electrode is generated. Prevents changes in the circuit conditions of the circuit, which allows the discharge current peak value Ip, the discharge pulse time τon, and the pause event τoff.
It is possible to provide a novel attachment for drilling electric discharge machining, which can carry out drilling electric discharge machining with high accuracy in a stable electric discharge machining state without changing the waveform relationship and the like.

The configuration of the present invention is not limited to the above-described embodiment, and for example, the mounting method in the shape of the conduction 3 and the working relationship with the spring 4, or the configuration of each of the other elements is also the present invention. The design can be freely changed within the scope of the above purpose, and the diameter of the perforations can be arbitrarily selected, and the present invention includes all of them.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an embodiment of an attachment for punching electric discharge machining according to the present invention. 1 ... Attachment for drilling electric discharge machining 2 ... Main body 2a ... Guideway 2b ... Suction line 3 ... Conductor 4 ... Spring 5 ... Special screw 7 ... Pipe electrode 9 ... Workpiece Body 10 ... EDM power supply 11 ... Holding handle

Claims (1)

(57) [Claims] 1. A tip portion of the pipe-shaped electrode, comprising: a guide passage through which the pipe-shaped electrode is inserted; and a pipe passage for sucking a working liquid which is supplied through the inside of the pipe-shaped electrode and ejected from the tip portion. And the main body portion disposed close to the surface of the workpiece and the pipe-shaped electrode inserted in the main body portion can come into contact with the pipe-shaped electrode from a direction substantially perpendicular to the axial direction of the electrode. As described above, the conduction member is attached to the main body so that it can move back and forth, and the inner end of the conduction member is constantly pressed against the pipe-shaped electrode by applying the elastic force in the perpendicular direction to the conduction member. An attachment for perforation electric discharge machining, comprising: a spring that presses against the inner wall surface of the guide path on the side opposite to the contact side; and a means for connecting the outer end side of the conduction to a power supply for electric discharge machining.