JPH0620672B2 - Nozzle device for wire cut electrical discharge machining - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention faces a workpiece through a minute gap to a wire electrode that is axially renewed and fed between a pair of positioning guides arranged at intervals. Arranged, while jetting and supplying a working liquid from the nozzle device provided coaxially with the wire electrode on both sides of the workpiece to the facing machining portion of the wire electrode and the workpiece,
Intermittent voltage pulses are applied between the wire electrode and the work piece to repeatedly generate electric discharge, and the work piece is relatively moved in a direction substantially perpendicular to the axial direction of the wire electrode to form a desired contour shape. The present invention relates to a nozzle device used for wire-cut electric discharge machining, and more particularly to a nozzle device having a machining liquid leakage prevention means suitable for high-speed cutting.

(Prior art) In wire-cut electric discharge machining, in order to perform high-speed machining, increase the machining fluid pressure, flow velocity, or flow rate in the machining area to generate bubbles in the machining section or trap air bubbles from the outside. It is necessary to keep the temperature low in order to reduce the inflow and increase the liquid flow in the processing portion to prevent the occurrence of air discharge, to eliminate the machining waste at a high speed, and to prevent the wire electrode from breaking.

However, if the amount of working fluid supplied or the fluid pressure is increased and jetted from the nozzle to the working part, the amount of leakage from the tip of the nozzle to the outside without passing through the working part and the amount of scattering to the surroundings will also increase. The machining fluid jetted and supplied from the nozzle of can not sufficiently affect the machining fluid flow etc. which is jetted and supplied from the other nozzle to flow through the machining section, and the expected amount of machining fluid supplied to the machining section, as expected. Or, the flow rate of distribution may not increase.

(Problems to be Solved by the Invention) In view of the above points, the present invention performs high-speed machining. Therefore, the machining fluid is leaked to the outside without flowing through the machining section, or the flow rate of the machining fluid flowing down is reduced, resulting in machining fluid. An object of the present invention is to provide a nozzle device for wire-cut electric discharge machining, which can increase the flow rate and pressure flowing to the machining part.

(Means for Solving the Problems) According to the present invention which achieves this object, at least one of the nozzle devices provided on both sides of the workpiece has an annular sponge shape surrounding the tip of the nozzle. A machining fluid leakage prevention member formed of a body and a machining fluid leakage prevention member which is provided separately from the nozzle device so as to be movable in the axial direction of the wire electrode between the pair of positioning guides and to which the machining fluid leakage prevention member is attached at the end. And a mounting body.

Embodiment An embodiment of the present invention will be described below with reference to the drawings. The drawing is a diagram showing a configuration example around a machining liquid jetting nozzle to which the present invention is applied, wherein 1 is a wire electrode, and 6A and 6B are the wire electrode 1
Upper and lower arms to which the guide rollers 7A and 7B are attached, which are attached to a column or the like of the apparatus main body (not shown). 8A and 8B are arm 6A, which can be vertically adjusted by a manual handle or motors 9A and 9B.
6B is a support member, 10 is an energizing pin,
This constitutes an upper energizing device which is attached to the support member 8A and which applies a voltage to the wire electrode 1 by being brought into contact with the wire electrode 1 which is pressed and displaced by a wear resistant and insulating pressing pin 10 '. Reference numeral 11 is an energizing roller serving as a lower energizing device which also serves as a lower guide roller, and 12 and 13 are fine adjustments of the positions of the supporting members 8A and 8B in the directions perpendicular to the axis of the wire electrode 1 (X-axis and Y-axis directions described later). It is a hollow cylindrical nozzle body that is movably or fixedly mounted, and openings 14, 15 and 16, 17 are formed in the upper and lower end surfaces of these nozzle bodies 12, 13, respectively.

Inside the nozzle bodies 12 and 13, guide holders 20 and 21 of vertical positioning guides 18 and 19 are coaxially fixed, respectively, and a lower end opening 15 of the upper nozzle body 12 and a lower nozzle body 12 are provided. Nozzles 22 and 23 are coaxially fixed to the upper end opening 17 of the nozzle 13 so as to face each other, or fitted so as to be movable in the axial direction as shown in the drawing. The nozzle 22 constitutes an upper nozzle device, and the nozzle body 1
3 and the nozzle 23 constitute a lower nozzle device. The guide holders 20 and 21 are the nozzle body 1
2 and 13 are hollow cylinders having holes 20a and 21a through which the working fluid flows. In addition, the nozzles 22 and 23 of this example
Is a hollow cylindrical body having a desired axial length, inner diameter and axial diameter restriction, and the outer diameters of the flange portions 22a and 23a in the nozzles 22 and 23 are the same as the inner diameters of the tip portions of the nozzle bodies 12 and 13. Flanges 22 of substantially equal design
a and 23a prevent the nozzle bodies 12 and 13 from falling off. 22A is a push spring provided as needed.

The pressurizing supply hoses 25 and 26 of the working fluid are attached to the nozzle bodies 12 and 13, respectively, and the working fluid is supplied to the nozzle bodies 12 and 13 at predetermined pressures and flow rates from the hoses 25 and 26, respectively. The guides 18 and 19 are cooled and jetted from the upper and lower nozzles 22 and 23 to the processing portion 27 of the workpiece 24 from above and below, respectively, and from the upper and lower openings 14 and 16 of the respective nozzle bodies 12 and 13. It jets and cools the wire electrode 1, the energizing pin 10, and the energizing roller 11. 30 is a processing groove, 3
Reference numerals 9 and 40 show the flows of the working liquid ejected from the upper and lower nozzles 22 and 23, respectively.

The workpiece 24 is fixed to a machining table 31, and the machining table 31 is controlled by an X-axis motor 32 and a Y-axis motor 33 on a plane perpendicular to the axis of the wire electrode 1 under the control of a numerical controller. It can move freely along the contour shape. In addition, the wire electrode 1 is pulled out from a storage reel provided in a column or the like of an apparatus body (not shown) via a brake roller or the like, extends downward from the guide roller 7A portion, the energizing pin 10 and the upper nozzle body 12 are provided.
And the nozzle 22, the processing part 27 of the workpiece 24, the lower nozzle 23 and the nozzle body 13, and the lower arm 6B.
It is adapted to be wound up or collected on a winding reel or a collecting container such as a column main body via a winding roller (not shown) via the energizing roller 11 and the guide roller 7B. Then, an intermittent voltage pulse is applied between the work piece 24 and the wire electrode 1 to perform electric discharge machining.

Therefore, in this embodiment, the upper and lower nozzle bodies 12,
The mounting bodies 41 and 42 of the working fluid leakage prevention members 43 and 44 are coaxially and vertically movable, respectively, and the nozzles 22 and 23 are coaxially enclosed at the lower and upper ends of the mounting bodies 41 and 42, respectively. Has a cylindrical or annular shape,
Further, the processing liquid leakage preventing members 43 and 44 made of synthetic resin (preferably flexible polyurethane foam or the like) having a sponge shape are attached. Upper and lower machining fluid leakage prevention member 4
Of the 3, 44, the upper one 43 comes into contact with the upper surface of the work piece 24 due to its own weight and the weight of the mounting body 41, and the lower one 44 is a collar 45 provided on the nozzle body 13.
And a ring 46 attached to the attachment body 42 presses the lower surface of the workpiece 24 weakly by the force of a pressing spring 47 interposed between the ring and the ring. 48 and 49 are nozzle bodies 12 and 1, respectively
3 is a retaining collar provided in No. 3, which is
Rings 46 and 5 attached to the attachments 41 and 42, respectively
It is intended to prevent it from coming off by receiving 0.

If such processing liquid leakage prevention members 43 and 44 are provided,
It is possible to prevent the leakage of the machining fluid which is ejected from the nozzles 22 and 23 and does not reach the machining portion 27 through the gap G between the workpiece 24 and the nozzles 22 and 23 as shown by the phantom line 51, and the machining amount is reduced accordingly. The flow rate, flow velocity, or hydraulic pressure of the machining liquid reaching the portion 27 increases. In addition, the function of preventing the leakage of the machining fluid is that the machining fluid leakage prevention members 43 and 44 are made of a sponge-like elastic material, so that the surface of the workpiece 24 has unevenness such as undulations. Even if there is a change and the distance between the nozzle device and the work piece 24 changes, these members 43 and 44 can always be brought into contact with the surface of the work piece, and further, these mounting members. Since the mounting bodies 41 and 42, which are the above, are movable up and down, even if the distance between the nozzle device and the surface of the workpiece 24 is relatively large, these members 4 can be tracked according to the large variation.
It is possible to keep 3, 44 in contact with the workpiece 24 at all times. In addition, when starting processing, each nozzle 2
The vertical position of the nozzle device is adjusted to set the positional relationship between the nozzles 22 and 23 and the workpiece 24 so that the jetting state of the machining fluid from the nozzles 2 and 23 is in a desired good state. It is necessary to adjust and set each pressure of the working fluid supplied to the nozzles 22 and 23 of the
When the nozzle device 44 is formed integrally with the nozzle device, the members 43 and 44 come into contact with the workpiece 24 when the nozzle device is brought close to the workpiece 24.
Since it is not possible to visually confirm the jetting and supplying state of the working fluid from 23, it is necessary to adjust the vertical position of the nozzle device and the pressure of the working fluid to be supplied to the hoses 25 and 26. However, according to the present invention, the leakage prevention members 43 and 44 are fixedly held by the mounting bodies 41 and 42 which are vertically movable and provided separately from the nozzle device. From the above, by adjusting the vertical position of the nozzle device and the pressure of the supplied processing liquid with the members 43 and 44 separated from the workpiece 24 by manual operation as necessary, these adjustment settings are made for each nozzle 22. , 23, it is possible to easily achieve the desired optimum state while visually observing the jetting state of the working fluid.

Although the support member 8A of the upper nozzle device is usually configured to be adjustable in vertical position, the position of the lower surface of the work piece 24 is set on the processing table 31 regardless of the plate thickness of the work piece. Since it is defined by the reference surface on which is mounted and fixed, the support member 8B of the lower nozzle device does not necessarily need to be adjustable in vertical position.

In this embodiment, the working fluid leakage prevention members 43 and 44 are
Are contacted by gravity or spring force. However, if a magnet is mixed into these members 43 and 44 (as a mixing mode, a small powdery magnetic material is mixed into the member 4).
3, 44 is magnetized entirely by a permanent magnet or an excitation coil, and permanent magnet powder such as already magnetized ferrite or Somerium cobalt magnet is directionally embedded by mixing and solidification, or the member 43 , 44 are attached to the surface portion of the workpiece 24 facing the workpiece 24 by evenly distributing them, or by mounting or embedding a plurality of small permanent magnet pieces, or by mounting a thin permanent magnet ring having the same shape as the members 43, 44. In some cases, the members 43 and 44 are attached to the facing surface portion when the workpiece 24 is a magnetic material.
4 can be adsorbed, and the leakage of the working fluid can be prevented more reliably.

In addition, in the above-mentioned embodiment, the example in which the two fixed or movable nozzles 22 and 23 face each other in the vertical direction has been shown, but there may be a case where they face each other in the horizontal direction. Further, among the processing liquid leakage prevention members 43, 44, since the upper member 43 can be suspended and held by gravity, the member 43 can be attached and held to the attachment body 41 by using a flexible film body such as a belt or a foil. It may be configured to be attached, suspended, and held through the above. In such a wire-cut electric discharge machining, in the case of the structure of the machining device in which the machining part of the wire electrode 1 is updated and moved in the vertical direction as in the illustrated embodiment, for example, the machining liquid jet pressure and the flow rate from the lower nozzle 23 are By setting it to be larger than that of the upper nozzle 22, the jetting machining liquid from the lower nozzle 23 rises in the machining portion and collides with the jetting machining liquid from the upper nozzle 22 near the upper end of the workpiece 24. Or, the work piece 2
In order to smoothly renew the working fluid in the working section, it is preferable to perform working in a state where the working fluid is supplied so as to jet up to the upper surface of 4 to some extent and collide with the jetting working fluid from the upper nozzle 22. In a different machining liquid supply mode, the supplied machining liquid radially spreads and flows around the nozzle 22 on the upper surface of the workpiece 24, or the supplied machining liquid spreads to the processed groove side near the upper surface. Therefore, if at least the upper member 43 is provided as a machining fluid leakage prevention member, it is possible to suppress the outflow of the machining fluid supplied on the upper surface of the workpiece 24 that spreads radially to the periphery. Although it depends on the structure of the lower and upper nozzles 23, 22 and the like, approximately 80% or more of the objects and effects of the present invention can be achieved. This means that the two nozzles are opposed to each other in the horizontal direction. In the case of horizontally updated moved to apparatus constituting the wire electrode Te also is applicable substantially the same manner.

As described above, the mounting body 41 portion of the machining fluid leakage prevention member 43 in this case suppresses the expansion of the machining fluid jet by the nozzle 23 on the high jetting fluid pressure side and the jet flow of the other nozzle 22. Is a mode in which
In the vicinity of the processing portion such as the processing gap, the processing liquid jets while maintaining a certain level of pressure to reduce the wire electrode electrode breakage ratio and stabilize the processing state to improve the processing speed.

(Effect of the Invention) According to the present invention, it is possible to increase the flow rate, flow velocity or hydraulic pressure of the working liquid supplied to the working portion, and reduce the generation of bubbles in the workpiece and the entrainment and inflow of air bubbles from the outside. As a result, it is possible to prevent the occurrence of air discharge, and to sufficiently cool the wire electrode in the working portion to generate a working liquid flow suitable for high-speed working. Further, the machining fluid leakage prevention member is made of a sponge-like body and is highly stretchable, and the machining fluid leakage prevention member of this sponge-like body is provided separately from the nozzle device so as to be movable in the axial direction of the wire electrode of the machining section. Since it is fixed and supported by the mounting body provided on the workpiece, even if the surface of the workpiece has some irregularities such as undulations, the machining liquid leakage prevention member can be processed without obstructing the machining feed. Processing can be performed in a state of being in contact with the surface of an object. or,
Since the mounting body that fixedly supports the machining fluid leakage prevention member is configured to be movable separately from the nozzle device, it is possible to adjust the positional relationship between the nozzle device and the workpiece at the start of machining, etc. It is possible to easily adjust the pressure of the working fluid supplied to each of the nozzles to an optimum state while visually observing the jetting state of the working fluid from each nozzle.

[Brief description of drawings]

The drawing is a wire-cut electric discharge machine showing an embodiment of the present invention.

Claims (2)

[Claims] 1. A work piece is arranged to face a wire electrode that is renewed and fed in an axial direction between a pair of positioning guides arranged at intervals with a minute gap therebetween, and the wire electrode is provided on both sides of the work piece. While the machining liquid is jetted and supplied from the coaxial nozzle device to the opposing machining area between the wire electrode and the workpiece, intermittent voltage pulses are applied between the wire electrode and the workpiece to repeatedly generate electric discharge. A nozzle device used for wire-cut electric discharge machining that performs a desired contour shape by relatively moving the workpiece in a direction substantially perpendicular to the axial direction of the wire electrode, and is provided on both sides of the workpiece. At least one of the nozzle devices has a machining liquid leakage prevention member formed of an annular sponge-like body surrounding the tip of the nozzle, and a nozzle device movably in the axial direction of the wire electrode. Vignetting nozzle device for wire-cut electrical discharge machining and having a said machining fluid leakage preventing member is attached working fluid leakage preventing member mount to the end. 2. The nozzle device for wire-cut electric discharge machining according to claim 1, wherein the machining fluid leakage prevention member has a magnet on the inside or on the surface facing the workpiece.