JPH01205926A - Band wire-cut electric discharge machining and device therefor - Google Patents

Abstract

PURPOSE:To improve the working efficiency in the whole of electric discharge machining by installing a pressing roll which vertically presses a wire having a circular section which is pulled out according to the fact that a part of a cut member is rectilinear form or curved form and forms an electric discharge electrode having a state suitable for working so that the pressing down quantity can be adjusted. CONSTITUTION:A wire 47 having a circular section is pulled out from a bobbin 49, and before the advance direction is changed towards an electric discharge region, the wire 47 is vertically pressed through a pressing roll 51, and sent as an electric discharge electrode 57 having a desired shape into an electric discharge working part, and electric discharge machining is carried out. In this case, if a part of a cut member W has a rectilinear form, each pressing- down quantity of the upper and lower rolls 53 and 55 in the pressing roller 51 is increased, and the electric discharge electrode 57 is formed to a relatively thin form. When the part has a curved form, the pressing-down quantity of the upper and lower rolls 53 and 55 is reduced, and the electric discharge electrode 57 is formed to a relatively short length in the advance direction of the electric discharge machining. Therefore, the working efficiency can be improved by forming the shape of the electric discharge electrode 57 according to the rectilinear or curved line form.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a band wire cut electric discharge machining method and apparatus, and more particularly, to a band wire cutting electric discharge machining method and apparatus for drawing out a conductor having a long circular cross section held on a bobbin. Then, before changing the direction and hanging down in the electrical discharge machining area, roll the top and bottom of the conductor with a rolling roll,
This is rolled into a band shape and the band wire is released.
′? The present invention relates to an electric discharge machining method and apparatus used as an R pole.

In this case, the reduction amount of the rolling roll can be changed at any time by remote control or automatic control, depending on whether a straight portion or a curved portion is to be processed, even while the discharge electrode is moving.

(Prior art) A conventional electric discharge machine has a
There is no structure in which the cross-sectional shape of the electrode is changed while the discharge electrode moves to the discharge region.

(Problems to be Solved by the Invention) The advantages and disadvantages of conventional open-circuit electrodes will be compared by dividing them into so-called round wire electrodes with a circular cross section and so-called band wire electrodes with a flat plate-like cross section.

For example, for a round wire electrode with a diameter of 0.35 mm, its cross-sectional area is approximately 0.096 mm2, and its processing speed is 25 mm.
It was 0 to 300n+n+2/win.

The width to be machined (kerf width) can be calculated as approximately 0.41111, which is the sum of the diameter and the discharge gap of 0.03 mm on both sides.

The current plate thickness is 0.111111 and the width of the flat part is 0.96m.
Taking a 5+ band wire electrode as an example, the cross-sectional area of the discharge electrode is approximately 0.096 mm2 and the diameter is 3.5n+5 (7
) Same as round wire, the kerf width is 0.16n+m.

In general, the electrical energy that can be supplied to an electrode is proportional to its cross-sectional area if the electrode is made of the same material, and the amount of processing work is expressed by the volume of material cut from the same workpiece, so the above-mentioned round wire with the same cross-sectional area The amount of work with the band wire and the band wire is approximately 2.5 times as deep as 0.41++v divided by 0.16nv with the same electrical energy.

In other words, if the supplied electrical energy is the same, the round wire electrode will be 1/2 the band wire electrode in the straight cut section.
5 also had the problem of slow cutting speed.

When cutting the workpiece in a straight line, the above is the case, but when cutting in a curved manner, with a round wire, you can immediately enter a 60 degree curve without stepping at the beginning of the curved cutting. However, in the case of band wire, there is a relatively long width part at the back in the direction of movement, and at the beginning of curved cutting, the forward movement is once zero (by stepping on the foot), and the direction is adjusted by gradually turning around the center of the width. It has to change.

In other words, when cutting curved sections, the cutting speed was faster with round wire than with band wire, which was many times slower.

[Structure of the Invention] (Means for Solving the Problems) In order to solve the problems of the conventional device described above, the present invention has the following features:
The method is to pull out a wire with a circular cross section from the bobbin,
Before changing the direction of movement toward the discharge area, the upper and lower portions of the circular shape are rolled using rolling rolls, and a relatively thin discharge electrode with a large rolling reduction is used for discharge machining the straight portions and the curved portions. Electric discharge machining is performed using a discharge electrode whose length in the direction of progress of the discharge machining is kept relatively short by reducing the amount of reduction. At the part where the wire is pulled out from the wire and before it changes direction toward the discharge area, rolls for rolling the wire up and down are installed so that the amount of rolling can be adjusted freely even while the wire is moving.

(Function) The electric discharge machining method and apparatus of the present invention adjusts the reduction amount of the rolling roll before the discharge electrode reaches the machining area depending on whether the electric discharge machining is to be performed on a straight line or a curved area, thereby increasing the machining efficiency of the entire electric discharge machining. It increased the

(Example) FIG. 1 shows a wire-cut electric discharge machine 1 as a side line in which the present invention is implemented, and the base 3. Column 5. The upper arm 7 forms a C-shape. Bed 9 is on base 3. Y table 1 that is driven by an electric motor and a ball screw and is movable in the Y-axis direction (front and back directions of the page)
1. An X-table 13 is provided thereon, which is driven by an electric motor and a ball screw and is movable in the X-axis direction (left-right direction in FIG. 1).

This X-table 13 has a rectangular tube shape with an upward opening and a bottom, and is provided protruding from the column 5 to the lower arm 15, and has a lower guide roller 19 for the discharge electrode 17 at its front end. A power supply shoe 21, a lower guide 23, etc. are provided.

A cylindrical rotary table 25 is provided above the X-table 13 and can be rotated and positioned by an electric motor and gears, and a workpiece W is fixed to the upper surface of the rotary table 25 by appropriate means.

Above the rotary table 25 described above, the rotary table 2
A wall 27 for preventing scattering of a discharge liquid such as a transparent organic gas is provided at an extended position of the outer circumferential wall surface 5.

The above-described upper arm 7 is bent downward at a position corresponding to the lower guide 23, and a guide rail 31 of the slide plate 29 is provided at this portion.

The slide plate 29 is driven by an electric motor and a ball screw (not shown), is guided by the guide rail 31, and can be moved up and down according to the height of the workpiece W.

Furthermore, an upper guide 33 is placed on the slide plate 29. ! The upper guide 33 is provided with a guide rail 37 driven and guided by the guide rail 135 in a substantially horizontal direction, and the upper guide 33 is also provided with a power supply shoe 21 in the middle and a guide roller 19 at the lower end, similarly to the lower guide 23. .

The upper guide 33 mentioned above is replaced by the lower guide 2 in FIG.
The reason why the position is changed to the left and right from directly above the electrode 3 is that it is convenient when performing electric discharge machining by tilting the discharge electrode 17 left and right in the discharge area.

Above the guide rail 31 described above, brake pulleys 41 and 43 are provided before and after an idler pulley 39 that changes the moving direction of the discharge electrode 17 to the downward direction.

A belt 44 is passed around between the brake pulleys 41 and 43, and strongly presses the discharge electrode 17 against the idler pulley 39 from outside the idler pulley 39.

On the other hand, after the discharge electrode 17 has penetrated the workpiece W, the direction of movement is changed again by the free rotating pulley 45 provided at the lower end of the lower guide 23, and the lower arm 15 and column 5 are used to recover the discharge electrode 17. A pull pulley (not shown) is provided in the process of the box 46 moving, and the box 46 is strongly pulled.

Therefore, the discharge electrode 17 is connected to the brake pulleys 41 and 4 described above.
Due to the action of 3, the discharge force receives strong tension and ensures linearity.

In one embodiment of the present invention, a bobbin 49 on which the round wire 47 is wound up is provided above the column 5 of the electric discharge machine 1 to serve as an uncoiler, and the round wire 47 drawn out from the bobbin 49 is Go to the free rotating pulley 39 mentioned above.

A rolling roll 51 is provided between the bobbin 49 and the idler pulley 39. These rolling rolls 51 are upper and lower rolls 5 of the same diameter.
3.55 may be a general type in which the gears are meshed with gears and rotate in opposite directions at the same speed, and the bearings supporting both ends of the shaft of the upper roll 53 are integral and can be operated by remote control or numerical control at the same time. This automatically sets the separation distance between the upper and lower rolls 53 and 55.

Therefore, on the right side of the rolling roll 51 shown enlarged in FIG. 2, there is a band wire discharge N electrode 57 which has been pressurized to a desired reduction amount and is used as a discharge electrode in subsequent discharge machining.

[Effects of the Invention] As is already clear from the detailed description above, the band wire cut electric discharge machining method and apparatus embodying the technical idea of the present invention can machine a discharge electrode that constantly moves and generates a new discharge. Since the cross-sectional shape is adjusted in advance to achieve the most efficient machining depending on whether the part of the material to be cut is a straight line or a curve, the cutting speed throughout the entire machining process is fast and highly efficient cutting can be ensured.

Although the present invention does not mention automatic adjustment using a computer, it is easy to implement automatic adjustment control in this way, and other design changes can be made without departing from the technical idea of the present invention. Of course.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway elevational view showing an example device of the present invention introduced into a general electric discharge machine, and FIG. 2 is a partially enlarged explanatory view of a positive pressure roll. (Explanation of symbols representing main parts of the drawings) 1...Wire-cut electrical discharge machine 17...Discharge electrode 47...Round wire 49.
...Bobbin 51...Roll roll 53...
Upper roll 55...Lower roll 57...Hand wire discharge electrode agent Patent attorney Yasuo Miyoshi

Claims (2)

[Claims] (1) Comparison in which a wire with a circular cross section is pulled out from a bobbin, and before changing the direction of movement toward the discharge area, the upper and lower parts of the circle are rolled using rolling rolls, and the reduction amount is increased for discharge machining of the straight part. Using a discharge electrode with a thin target thickness,
A band wire cut electric discharge machining method characterized in that electric discharge machining of a curved portion is performed using a discharge electrode whose length in the direction of progress of electric discharge machining is kept relatively short by reducing the amount of reduction. (2) A wire with a circular cross section is pulled out from the bobbin, and rolls for rolling the wire up and down are provided at the portion before changing the direction of travel toward the discharge area, so that the amount of rolling can be adjusted freely even while the wire is moving. Band wire cut electric discharge machining equipment.