JPH0739057B2 - Wire electrode guide device used for wire cut electrical discharge machining - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to a guide device for positioning and guiding a wire electrode that travels and moves in the axial direction in a wire-cut electric discharge machining at a machining portion facing a workpiece. Regarding

[Conventional technology]

In the wire-cut electric discharge machining, a fine wire wire electrode is axially moved and moved between a pair of positioning guides arranged at intervals with a predetermined tension and speed, and a workpiece is attached to the wire electrode between the positioning guides. While the machining liquid is supplied to the machining gaps formed facing each other, intermittent machining voltage pulses are applied between the wire electrode and the workpiece to repeatedly generate electric discharge pulses and the wire between the positioning guides is positioned on the workpiece. By providing relative machining feed in the X and Y axis directions that are orthogonal to the axial direction of the electrodes, the desired shape is cut out and cut. As a wire electrode, the wire diameter is usually
Since a thin wire of copper, brass or the like having a diameter of about 0.05 to 0.5 mmφ is used, the tension that can be applied to the wire electrode may not be so large, and the wire electrode is apt to vibrate due to various external forces. The factors that cause vibration are the external force that the wire electrode traveling in the axial direction receives from the traveling system, the external force that acts with the supply of machining fluid, the external force that acts with machining feed, and the pressure of the discharge pulse generated in the machining gap. Also, the pressure due to the burst of bubbles may be considered. Also, in the normal first cut, since both side surfaces orthogonal to the machining feed direction of the wire electrode face the machining groove wall surface of the workpiece and the external force acting is balanced, the wire electrode is machined. It will bend backwards, which is the opposite of the feed direction, but in the case of a second cut that re-processes the machined surface after the first cut or removal processing of the surface of the workpiece, it is orthogonal to the machining feed direction of the wire electrode. Since one side of both side surfaces is in an open state without the facing wall surface of the workpiece, the wire electrode is easily bent and vibrated toward the open side in the direction orthogonal to the machining feed direction. The vibration of the wire electrode in the machined part due to such various causes occurs with the pair of positioning guides as fulcrums at both ends, and the machining groove width is widened or non-uniform due to the occurrence of vibration. A streak mark is formed on the surface, which reduces the processing accuracy.

For this reason, it has been conventionally considered to prevent or reduce the vibration of the wire electrode in the processed portion.
Japanese Unexamined Patent Publication (Kokai) No. 6 proposes a guide device in which a vibration-proof material is interposed between a positioning guide and a guide holder.

[Problems to be solved by the invention]

However, the guide device described in the above publication is
Hard rubber or plastic or damping alloy is used as a vibration isolator, and it may be possible to maintain the positioning accuracy of the wire electrode as a positioning guide by using these vibration isolator, Since these vibration damping materials do not necessarily have a large vibration damping effect, the vibration reduction effect of the wire electrode still remains unsatisfactory. Further, when a substance having rubber-like elasticity or viscoelasticity having a large vibration damping action is used as the vibration isolator, the positioning guide itself is inevitably displaced by the vibration of the wire electrode, which causes a problem in positioning accuracy.

In view of such a problem, the present invention is a guide that can sufficiently reduce the vibration of the wire electrode and that can stably hold the position of the positioning guide and position the wire electrode of the processed portion with high accuracy. The purpose is to provide a device.

[Means for solving problems]

In order to achieve this object, the wire electrode guide device of the present invention is a cylindrical fixing member having a shaft-shaped die guide having a hole through which a wire electrode is inserted and having an inner dimension larger than the outer dimension of the die guide. Are arranged coaxially within the die guide outer peripheral wall and the fixing member inner peripheral wall to dispose a coupling member in a radiation isomorphic manner to couple the two, and to form a gap between the die guide outer peripheral wall and the fixing member inner peripheral wall. It is characterized by being formed by filling a substance having rubbery elasticity or viscoelasticity.

[Action]

By connecting the die guide for positioning the wire electrode of the processing part to the tubular fixing member by the connecting member,
The die guide is not displaced due to the vibration of the wire electrode, the die guide is stably held at a predetermined arrangement position, and the wire electrode of the processing portion is positioned with high accuracy. In addition, the shaft-shaped die guide and the cylindrical fixing member are coaxially arranged, and the gap between the two is filled with a substance having rubber-like elasticity or viscoelasticity having a large vibration damping effect, so that Vibrations propagated to the die guide are efficiently damped, and vibrations propagated from the die guide to the coupling member are also efficiently damped because the coupling member surface is in contact with the filling material, and the vibration of the wire electrode is sufficiently reduced. To be done.

〔Example〕

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

FIG. 1 is a simplified explanatory view showing a state of wire cut electric discharge machining using the guide device of the present invention. In Figure 1,
Reference numeral 1 is a wire electrode, and 2 is an object to be processed, which face each other to form a processing gap. Reference numerals 3 and 3 denote a pair of die guides for positioning the wire electrode 1 of the processed portion facing the workpiece 2, and the wire electrode 1 is fed from a reel (not shown) and positioned by the die guides 3 and 3, and the arrow marks To move in the direction. The traveling speed and tension of the wire electrode 1 are controlled by a brake and a driving roller (not shown), and the wire electrode 1 travels at a predetermined speed and tension. 4, 4 are machine bodies to which the guide device is attached, 5 is a machining power source for applying a machining voltage pulse between the wire electrode 1 and the workpiece 2, and 6
Is a nozzle for supplying a machining liquid to the machining gap, and 7 is a workpiece 2
It is a processing table that holds and holds.

With this configuration, the machining power is supplied from the machining power supply 5 to the wire electrode 1 while the machining liquid is supplied from the nozzle 6 to the machining gap between the wire electrode 1 and the workpiece 2 which are renewed and fed between the pair of positioning guides 3, 3. An intermittent machining voltage pulse is applied between the workpieces 2 to repeatedly generate an electric discharge pulse, and the machining table 7 is normally directed to the axial direction of the wire electrode 1 between the die guides 3 and 3 according to an NC device command. By giving the machining feeds in the X and Y axis directions orthogonal to each other, wire-cut electric discharge machining of a target machining shape is performed.

2 and 3 show an embodiment of the guide device of the present invention. 2 and 3, 1 is a wire electrode, 3 is a shaft-shaped die guide having a hole through which the wire electrode 1 is inserted, and 10 is a cylinder having an inner size larger than the outer size of the die guide 3. The fixing member 10 is formed of a hard synthetic resin or a metal material having high rigidity that is commonly used, and the die guide 3 and the fixing member 10 are coaxially arranged. Numeral 9 is a coupling member for radiating and isolating between the outer peripheral wall of the die guide 3 and the inner peripheral wall of the fixing member 10. In this embodiment, four are arranged at 90 ° intervals to couple the outer peripheral wall and the inner peripheral wall. A rod-shaped or plate-shaped metal is usually used as the member, and the joining is performed by an appropriate means such as welding, adhesion, and screw fixing. Reference numeral 8 is a substance having rubber-like elasticity or viscoelasticity filled in the space between the outer peripheral wall of the die guide 3 and the inner peripheral wall of the fixing member 10. As the substance having rubbery elasticity, natural rubber or synthetic rubber is used. As the substance having the above, a polymer substance such as an acrylic resin or an epoxy resin, a colloidal dispersion system, or a polycrystalline substance such as a metal is used. In addition, a combination of these substances as appropriate, or the acrylic resin or epoxy resin and a metal,
A combination of boron, carbon, glass, fibers, etc. is used as the filling material. The guide device of the present invention is configured in this way, and the fixing member 10 is used by fixing it to the machine body 4.

In the guide device of the present invention, since the die guide 3 which is the positioning guide is integrally connected to the cylindrical fixing member 10 by the connecting member 9 as described above, the die guide 3 is displaced by the vibration of the wire electrode 1. In this way, the wire electrode is stably held in a predetermined arrangement position, and the wire electrode is accurately positioned in the processed portion. Although the vibration of the wire electrode cannot be avoided due to various causes, the axial die guide 3 and the cylindrical fixing member 10 are coaxially arranged, and the gap between the two has a high vibration damping characteristic. Since the substance 8 is filled, the vibration propagated from the wire electrode 1 to the die guide 3 can be efficiently damped, and the surface of the coupling member 9 is also in contact with the filled substance 8, so that the die guide The vibration propagated from 3 to the engaging member 9 can also be efficiently damped, and the vibration of the wire electrode can be damped sufficiently.

According to the experimental results, when a 0.2 mmφ copper wire is processed as a wire electrode using a conventional ordinary positioning guide, streaky irregularities of about 10 to 20 μm are formed on the processed surface, whereas the present invention When the guide device of No. 1 was used, the streaky unevenness could be reduced to about 1/10.

Further, since the guide device of the present invention uses the die guide as the positioning guide, it can stably guide the wire electrode regardless of the direction of the machining feed, and is orthogonal to the machining feed direction of the wire electrode. The wire electrode can be stably guided even when a second cut or the like is performed in which one side of both side surfaces does not face the workpiece and is in an open state.

〔The invention's effect〕

As described above, according to the guide device of the present invention, it is possible to sufficiently reduce the vibration of the wire electrode of the processing part, and to stably hold the position of the positioning guide at the predetermined arrangement position and to wire the processing part. The electrodes can be positioned with high precision, and as a result, highly accurate wire cut electric discharge machining can be stably performed.

[Brief description of drawings]

FIG. 1 is a simplified explanatory view showing a state of wire-cut electric discharge machining using a guide device of the present invention, FIG. 2 is a side sectional view of an embodiment of the present invention device, and FIG. 3 is an upper sectional view thereof. . 1 ... Wire electrode, 2 ... Workpiece, 3 ... Dice guide, 8 ... Substance having rubber-like elasticity or viscoelasticity, 9 ...
Coupling member, 10 ... Fixing member,

Claims (1)

[Claims] 1. A pair of guide devices for positioning and guiding a wire electrode traveling in the axial direction are arranged at a predetermined interval, and a work piece is opposed to the wire electrode between the pair of guide devices. A machining gap is formed, and a machining liquid is supplied to the machining gap, and an intermittent machining voltage pulse is applied between the wire electrode and the workpiece to repeatedly generate electric discharge pulses, and at the same time A guide device for use in wire-cut electric discharge machining, in which a desired shape is machined by providing a relative machining feed in a direction perpendicular to the axial direction of the wire electrode between the guide devices, the shaft device having a hole through which the wire electrode is inserted. The die guide is coaxially arranged in a cylindrical fixing member having an inner dimension larger than the outer dimension of the die guide, and the coupling member is dissipated between the outer peripheral wall of the die guide and the inner peripheral wall of the fixing member. Formed by arranging them in a shape and connecting them, and filling the gap between the outer peripheral wall of the die guide and the inner peripheral wall of the fixing member with a substance having rubber-like elasticity or viscoelasticity. Wire electrode guide device used for processing.