JPH0724979B2 - Wire cut electrical discharge machine - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wire-cut electric discharge machine, and more particularly, to a wire-cut electric discharge machine that performs machining in a state where ultrasonic vibration is applied to a wire electrode of a machining section facing a workpiece. Regarding the improvement of.

2. Description of the Related Art The present applicant has already applied the ultrasonic vibration to the die guide for positioning the wire electrode of the processing part to enhance the action of removing the processing waste from the processing gap, and also to prevent or eliminate the occurrence of a short circuit. We have proposed a wire-cut electric discharge machine that promotes high-precision machining at high speed.

Problems to be Solved by the Invention The wire electrode is usually a thin wire with a wire diameter of about 0.05 to 0.5 mmφ, and the gap between the die guide and the wire electrode is formed to be several microns, at most about 10 microns. Therefore, it is difficult to pass the wire electrode through the die guide. Therefore, instead of the dice-shaped guide, the wire electrode 1 is sandwiched between the V-shaped guide 7a having the V-shaped groove 7b and the flat flat guide 7c as shown in FIG. 2, for example. When using the guiding device to guide the wire electrode 1, the V-shaped guide 7a and the flat-shaped guide 7c are used.
It is conceivable that the wire electrodes are separated from each other to facilitate the passage of the wire electrode. However, in such a case, since only one V-shaped flat guide to which ultrasonic vibration is directly applied from the horn tip of the ultrasonic oscillator vibrates, it is necessary to efficiently and sufficiently apply ultrasonic vibration to the wire electrode. I can't.

In view of the above problems, the present invention uses a guide device that is a combination of a V-shaped guide and a flat guide as a wire electrode positioning guide device and that is configured to open and close a wire electrode holding portion. Another object of the present invention is to provide a wire-cut electric discharge machining device capable of performing ultrasonic vibrations on both V-shaped flat guides to efficiently and sufficiently apply ultrasonic vibrations to the wire electrode of the processing portion.

Means for Solving the Problems To achieve this object, the wire-cut electric discharge machining apparatus of the present invention uses one of a V-shaped guide and a flat-shaped guide as an ultrasonic oscillator as a guide device for positioning a wire electrode. It is fixedly installed on the tip of the horn and the other guide is fixedly installed on the tip of the shaft-like body, and a member for fixing and holding the ultrasonic oscillator and a substantially central part with both ends of the shaft-like body as free ends are fixedly held. And a V-shaped guide and a flat-shaped guide are arranged so as to be coaxial with each other and the V-shaped guide and the flat-shaped guide are opposed to each other so that a predetermined wire electrode is formed between the two guides. A guide device is provided, which is provided with means for opening and closing the wire electrode holding portion by moving the both fixed holding members relative to each other.

Action The pinching portion can be easily opened and closed by opening and closing the wire electrode pinching portion, and the wire electrode can be pierced with the V-shaped guide and the flat type guide separated from each other. it can. After passing through the wire electrode, the holding portion is closed and the wire electrode is held between both V-shaped flat guides in a predetermined state (a gap of several microns is formed between the guide and the wire electrode). The ultrasonic oscillator is operated while the wire electrode is travelingly moved in the axial direction, and the guide fixedly installed at the tip of the horn is ultrasonically vibrated in the axial direction of the horn integrally with the horn. Due to this vibration, the guide at the tip of the horn periodically presses the wire electrode, and a transverse wave is generated in the wire electrode with the vibration direction being the axial direction of the horn and the shaft. Further, the guide at the tip of the shaft body is periodically pressed through the wire electrode to the guide at the tip of the horn or to the wire electrode vibrating in transverse waves. As the periodic pressing force continues to act on the tip portion, a longitudinal wave having a node at the center portion and antinodes at both ends that are free ends is generated in the shaft-shaped body having the substantially center portion fixed.

In order to cause the axial body to resonate with ultrasonic vibration and generate longitudinal waves of large amplitude, is the axial body formed so that the natural frequency of the axial body is approximately equal to the oscillation frequency of the ultrasonic oscillator? ,
Alternatively, an ultrasonic wave having a frequency substantially equal to the natural frequency of the shaft is used, and as the member for fixing and installing the other guide,
By using a shaft-shaped body with both ends being free ends and approximately the center fixed, longitudinal waves with both ends antinode can be easily generated by resonating with ultrasonic vibration. Can be vibrated integrally with the shaft-shaped body in the direction of the shaft-shaped body with a large amplitude to periodically press the wire electrode.
As described above, not only the one guide at the tip of the horn but also the other guide facing the guide is vibrated with a large amplitude enough to periodically press the wire electrode, and the V-shaped guide and the flat-shaped guide are used. By vibrating the wire electrode, sufficient ultrasonic vibration is efficiently and efficiently applied to the wire electrode of the processed portion.

Embodiment An embodiment of the present invention will be described with reference to the drawings.

FIG. 1a is a plan sectional view of a guide device used in the present invention,
FIG. B is a waveform diagram showing a longitudinal wave generated in an axial body as a transverse wave waveform, FIG. 2 is a partially enlarged view of FIG. 1a, and FIG. 3 is a schematic view of a wire cut electric discharge machining apparatus of the present invention. is there.

In the figure, reference numeral 1 is a wire electrode, which is fed from a supply drum 2, travels and moves at a predetermined tension and speed, and is wound around a recovery drum 3. Reference numerals 4 and 5 are guides for changing the traveling direction of the wire electrode, and reference numerals 7 and 8 are a pair of guide devices for positioning the wire electrode 1 of the processing portion facing the workpiece 6. In this embodiment, the guide device of the present invention is used as the upper guide device 7. Reference numeral 7a is a V-shaped guide having a V-shaped groove 7b, 7c is a flat flat guide, and both guides 7a and 7c are made of a high hardness material such as diamond or sapphire. Reference numeral 10 is an ultrasonic oscillator, and 10'is a horn. The horn 10 'amplifies the amplitude of ultrasonic vibration of the oscillator of the ultrasonic oscillator 10 to perform longitudinal wave vibration with the tip as an antinode. The V-shaped guide 7a is fixedly installed at the tip of the horn 10 '. 9 is a mounting portion of the ultrasonic oscillator 10
10 is a member for fixing and holding. 11 is a shaft-shaped body, and a shaft-shaped body having a circular, quadrangular, polygonal or other cross-sectional shape is appropriately used, and a flat guide 7c is provided at the tip of the shaft-shaped body 11. 9a is a member for fixing and holding a flange portion 12 provided in the substantially central portion with both ends of the shaft-shaped body 11 as free ends by a mounting plate 13, and both of the ultrasonic oscillator 10 and the shaft-shaped body 11 are fixed. Fixed holding member 9 and
The horn 9'and the shaft 11 are arranged coaxially with each other and the V-shaped guide 7a and the flat-shaped guide 7c are arranged so as to face each other.
They are installed so as to form a predetermined wire electrode 1 holding portion between c, and the fixed holding member 9a is rotatably constituted by a hinge 14. By rotating the fixed holding member 9a, the wire electrode holding portion is opened and closed. To do. Further, the fixed holding member 9a is
The wire electrode 1 is sandwiched between the guides 7a and 7c, and is fixed to the fixed holding member 9 through the spacer 16 by the screw 15 in a state of being formed.

In the above configuration, the fixed holding member 9a is rotated to open the wire electrode holding portion to pass the wire electrode through, and then the member 9a is fixed to the fixed holding member 9 with the screw 15, so that the wire electrode 1 The ultrasonic oscillator 10 is operated while being sandwiched between the guides 7a and 7c, positioned, and moved and moved at a predetermined tension and speed, and a working liquid is supplied to the working gap, and the wire electrode 1 and the workpiece 6 are separated. A machining voltage pulse is applied and a relative machining feed in a direction perpendicular to the axial direction of the wire electrode 1 between the guide devices 7 and 8 is applied to the workpiece 6 to perform machining of a desired contour shape. The ultrasonic oscillator 10 uses ultrasonic waves of about 20 to 100 KHz. Then, as described above, the flat guide 7c is attached to the tip end of the shaft-like body 11 with the both ends being free ends and the substantially central portion being fixed.
As shown in Fig. 1b, the shaft-shaped body
Longitudinal waves whose both ends are antinodes with the flange portion 12 of 11 as a node can be easily generated by resonating with ultrasonic vibration. Not only the V-shaped guide 7a at the tip of the horn 10 ', but also the opposed flat-shaped guides. 7c can also be vibrated with a large amplitude to efficiently and sufficiently apply ultrasonic vibration to the wire electrode 1. For example, when the shaft 11 is made of an iron material and ultrasonic waves of 50 KHz are used, the speed of the sound wave in the iron material is about 5000 m / sec. Therefore, the shaft 11 having a length of about 5 cm may be used. Also, the horn 10 '
Flat guide 7c at the tip and V-shaped guide at the tip of the shaft 11
It goes without saying that the 7a may be fixedly installed.

As described above, according to the present invention, the V-shaped guide and the flat-shaped guide are opposed to each other to form the wire electrode holding portion, and the holding portion can be opened and closed. The operation to penetrate the electrode can be easily performed,
Further, a guide for forming a wire electrode holding portion is provided at the tip of the shaft-shaped body so as to face the guide of the tip of the horn of the ultrasonic oscillator, and the both ends of the shaft-shaped body are fixed as free ends in the substantially central portion. By doing so, both the V-shaped guide and the flat-shaped guide facing each other can be subjected to ultrasonic vibration of sufficiently large amplitude, and sufficient ultrasonic vibration can be efficiently applied to the wire electrode of the processed portion. High-precision processing can be performed at high speed.

[Brief description of drawings]

FIG. 1a is a plan sectional view of a guide device used in the present invention,
FIG. B is a waveform diagram showing a longitudinal wave generated in an axial body as a transverse wave waveform, FIG. 2 is a partially enlarged view of FIG. 1a, and FIG. 3 is a schematic view of a wire cut electric discharge machining apparatus of the present invention. is there. Reference numeral 1 is a wire electrode, 6 is a work piece, 7 and 8 are guide devices for positioning the wire electrode of a processing part, 7a is a V-shaped guide, 7c is a flat guide, 9 is a fixed holding member for an ultrasonic oscillator, and 9a is a shaft. Fixed holding member of the shape, 10 is an ultrasonic oscillator, 10 'is a horn,
11 is a shaft, 12 is a flange, 14 is a hinge, and 15 is a screw.

Claims (1)

[Claims] 1. A state in which a workpiece is disposed opposite to a wire electrode that is renewed and fed in an axial direction between a pair of positioning guide devices arranged at intervals, with a machining liquid being supplied to the machining gap. , Applying intermittent machining voltage pulse between the wire electrode and the workpiece to repeatedly generate electric discharge, and to perform relative machining feed to the workpiece in a direction substantially perpendicular to the axial direction of the wire electrode between the pair of positioning guides. In a wire-cut electric discharge machine for giving a desired contour shape, one of a V-shaped guide and a flat-shaped guide is fixedly installed at the tip of a horn of an ultrasonic oscillator as a guide device for positioning a wire electrode. In addition, the other guide is fixedly installed at the tip of the shaft-like body, and a member for fixing and holding the ultrasonic oscillator and a member for fixing and holding the substantially central part with both ends of the shaft-like body as free ends are provided. The horn and the shaft are coaxially arranged, and the V-shaped guide and the flat-shaped guide are arranged to face each other, and the both fixed holding members are installed so as to form a predetermined wire electrode holding portion between the both guides. In addition, the wire cut electric discharge machining apparatus is characterized by using a guide device including means for moving the both fixed holding members relatively to open and close the wire electrode holding portion.