JPH0158009B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an electric discharge machining method and an electric discharge machining apparatus used in the method, and more particularly to a wire electric discharge machining method and apparatus using a discharge wire.

[Prior Art] Traditionally, a machining tool and a workpiece are used as electrodes in an insulating liquid such as kerosene or water, and electric discharge generated by applying a voltage between the electrodes has been utilized. Electrical discharge machining methods are known in which machining is performed using One of these electrical discharge machining methods is the wire electrical discharge machining method, which has higher machining accuracy than normal electrical discharge machining methods, so it is widely applied to high-precision production machining such as press cutting dies. ing.

Such a wire electrical discharge machining method generally uses a device in which a discharge wire 1 made of copper, brass, tungsten, etc. is arranged in a straight line, as shown in FIG.
The discharge wire 1 and the workpiece 7 are fed out at a desired speed by a wire sending means such as No. 4, and are moved in a desired direction (for example, the X and Y directions in the figure). During this time, a desired voltage is applied from the discharge power source 9 to generate electric discharge, thereby performing machining. At this time, the wire feeding is performed in order to correct the electrode wear caused by the discharge, keep the distance between the discharge wire 1 and the workpiece 7 constant, and improve the machining accuracy. Further, while winding the discharge wire 1 using the wire take-up reel 15 or the like, a desired tension is applied to the discharge wire 1, and the distance between the discharge wire 1 and the workpiece 7 is maintained constant to improve machining accuracy. Efforts are also being made to make it easier.

However, in such a wire electric discharge machining method, the machined surface of the workpiece 7 has a shape that utilizes the linearity of the discharge wire 1, that is, a one-dimensional cross-sectional shape (here, the one-dimensional cross-sectional shape is, for example, a cylinder,
It refers to a surface shape formed by moving in a straight line, such as a cone or a prism, and of course it can be processed into a complex shape as shown in Fig. 6. Two-dimensional cross-sectional shapes (what is meant by two-dimensional cross-sectional shape here? , which is a surface formed by the movement of a non-linear line such as a curved line or a polygonal line, such as the above-mentioned toric shape, was impossible to create. Further, even when processing the workpiece 7 into a one-dimensional cross-sectional shape such as the above-mentioned cylinder, the processing speed was slow and inefficient.

[Problems to be Solved by the Invention] The present invention has been made in view of the above-mentioned points, and the main purpose of the present invention is to solve the drawbacks of the above-mentioned conventional examples and to create a two-dimensional cross-sectional shape. It is an object of the present invention to provide a novel wire electric discharge machining method and apparatus that can improve machining efficiency.

[Means for Solving the Problems] The present invention, which achieves the above object, uses a single electrical discharge machining method in which electrical discharge machining is performed by generating electrical discharge between an electrical discharge wire and a workpiece. A wire is spirally wound around a wire trajectory regulating means having a shape substantially the same as the shape of the workpiece surface formed by moving a non-linear line of the workpiece, and the discharge wire is caused to follow a spiral trajectory. This is a wire electrical discharge machining method characterized by performing electrical discharge machining while moving along the wire.

Another aspect of the present invention provides a wire electrical discharge machining apparatus configured to perform electrical discharge machining by generating electrical discharge between a discharge wire and a workpiece, in which a nonlinear line of the workpiece is A wire trajectory regulating means having a shape substantially the same as the shape of the workpiece surface formed by the movement of the wire is provided, a single discharge wire is wound around the wire trajectory regulating means in a spiral shape, and the discharge wire is caused to follow the spiral trajectory. This wire electrical discharge machining apparatus is characterized in that it performs electrical discharge machining by generating electrical discharge while moving the wire along the wire.

[Embodiments of the Invention] The present invention will be described in detail below based on the embodiment apparatus shown in FIGS. 1 to 5.

Figures 1 and 2 are cylindrical
This is an example of an embodiment apparatus for creating a shaped work surface, and FIG. 1 is a front view of the apparatus, and FIG. 2 is a cross-sectional view of the apparatus.

As shown in FIGS. 1 and 2, in this example, a single discharge wire 1 is moved along a spiral trajectory so as to draw a trajectory similar to the cylindrical shape of the surface to be machined, The workpiece 7 is processed into the shape. As the discharge wire 1, for example, copper, brass,
Various conventionally known wires made of conductive materials such as tungsten can be used without particular limitation. 2 is a wire trajectory regulating means for regulating the trajectory of the wire 1, and in this example, the wire 1 is moved along a spiral trajectory so as to draw a trajectory similar to the shape of the workpiece surface of the workpiece 7. It has a cylindrical shape so as to be movable, and is made of a non-conductive material so as to maintain insulation from the wire 1. Further, in order to facilitate feeding of the discharge wire 1, a spiral V-shaped groove is provided on the outer periphery of the means 2, and a discharge wire feed hole is arranged in the direction of the axis _O1 . Such wire trajectory regulating means 2
According to the method, since it is possible to make the discharge wire 1 draw a trajectory that has the same shape as the surface to be machined, it is possible to create a two-dimensional cross-sectional shape that was previously impossible, and it is possible to improve machining efficiency. You will also be able to do The material of the wire locus regulating means 2 is not particularly limited as long as it is non-conductive, but in consideration of abrasion with the discharge wire 1, hard and brittle materials (specifically, For example, ceramics, etc.) may be used.

Reference numeral 3 denotes a wire electrical discharge machining apparatus main body equipped with a positioning mechanism P, and is arranged so that the wire trajectory regulating means 2, which is rotatable via a bearing 4, can be opposed to the workpiece 7. Reference numeral 5 denotes a motor for giving rotational movement about the axis O ₁ to the wire trajectory regulating means 2 via a pulley 6, and 8 is a base for holding the workpiece 7. Reference numeral 9 denotes a discharge power supply, which supplies a direct current to the discharge wire 1 serving as an electrode and the workpiece 7 via a cord 10 to generate a discharge between the discharge wire 1 and the workpiece 7. 11
is an insulating liquid for maintaining insulation between the discharge wire 1 and the workpiece 7 and reducing wear and tear on the wire, and various liquids such as white kerosene or water are used.

Using the above-mentioned apparatus, electric discharge machining is performed, for example, as follows. First, with a desired tension applied to the discharge wire 1, the wire trajectory regulating means 2 is rotated by the motor 5, and the feed rate is approximately 1 to 2 mm/min (of course, depending on the material of the workpiece 7, etc.). The discharge wire 1 is sent at a speed of . Next, turn on the discharge power supply 9,
A discharge is generated between the discharge wire 1 and the workpiece 7. In this state, the wire trajectory regulating means 2 is
The discharge wire 1 is positioned to face the workpiece 7 via the means 2, and processing is performed. At this time, the workpiece 7 is coated with an insulating liquid 11, including for rust prevention purposes.
It is best to keep it immersed in water at all times. In addition, when machining is performed by rotating the workpiece 7 as in the case of FIGS. 3 to 5 described later, the discharge wire 1 is connected to the workpiece 7.
It is preferable to turn on the workpiece drive motor 12 and rotate the workpiece 7 before facing the workpiece 7 .

FIG. 3 is a diagram illustrating another embodiment of the present invention, in which a front view of an example of an embodiment apparatus for creating a toric-shaped work surface is shown.

In this example, the spherical wire locus regulating means 2 is used to form the surface of the workpiece 7 into a torlic shape. The wire trajectory regulating means 2 has a spiral wire trajectory regulating structure similar to that shown in FIGS. 1 and 2 (the groove shape may be V-shaped as shown in FIGS. ) is provided to facilitate regulation of the wire trajectory by the means 2. 12 is the workpiece 7
This is a workpiece drive motor for rotating the workpiece around the axis O0 via the pulley ₁₃ . In the present invention, it is not necessarily necessary to rotate the workpiece 7, but the present invention is made more effective by providing the rotation mechanism as described above and rotating the workpiece 7. be able to.

FIG. 4 is a diagram illustrating still another embodiment of the present invention, and in this example, a front view of an example of an embodiment apparatus for creating a processed surface having a V-shaped rotating surface shape is shown. has been done.

In this example, a bobbin-shaped wire trajectory regulating means 2 is used to create a V-shaped rotating surface-shaped work surface. The means 2 is provided with a wire trajectory regulating groove similar to that in the above example. In the present invention, although it is not necessarily necessary to provide such a wire trajectory regulating groove, the present invention can be made more effective by providing the groove.

FIG. 5 is a diagram illustrating still another embodiment of the present invention, in which a front view of an example of an embodiment apparatus for creating an R-spherical processed surface is shown. There is. In this example, the wire trajectory regulating means 2 is spherical in order to create an R-spherical processed surface.

In the embodiment apparatus shown in FIGS. 3 to 5, for example, the rotation axis O ₁ of the wire trajectory regulating means 2 and the rotation axis O ₀ of the workpiece 7 are set as shown in FIGS. 3 to 4. _{Alternatively ,} in _FIG . The present invention can be made even more effective by making the device swing from the center (heart) as a starting point.

[Effects of the Invention] As explained above, the present invention provides a novel wire electrical discharge machining method and apparatus that can create a two-dimensional cross-sectional shape that was previously impossible, and can also improve machining efficiency. It is now possible to provide
In addition, it has become possible to easily create a two-dimensional cross-sectional shape of a mold or the like made of hard metal at high speed and with high precision.

[Brief explanation of drawings]

1 and 2 show an example of an embodiment apparatus for creating a cylindrical-shaped work surface, respectively, FIG. 1 is a front view of the apparatus, FIG. 2 is a cross-sectional view of the apparatus, FIG. 3 is a front view of an example of an embodiment apparatus for creating a toric-shaped work surface, and FIG. 4 is a front view of an example of an embodiment apparatus for creating a V-shaped rotating surface shape work surface. , Figure 5 shows R
FIG. 6 is a front view of an example of an embodiment apparatus for creating a spherical workpiece surface, and FIG. 6 is a perspective view of an example of a conventional wire electric discharge machining apparatus. DESCRIPTION OF SYMBOLS 1...Discharge wire, 2...Wire trajectory regulating means, 7...Workpiece, 9...Discharge power supply.

Claims (1)

[Claims] 1. In a wire electrical discharge machining method in which electrical discharge is performed by generating electrical discharge between an electrical discharge wire and a workpiece, a single electrical discharge wire is used to control the nonlinearity of the workpiece. The method is characterized in that the electric discharge wire is wound in a spiral around a wire locus regulating means having a shape substantially the same as the shape of the surface to be machined formed by the movement of the wire, and electric discharge machining is performed while the electric discharge wire is moved along the spiral locus. Wire electrical discharge machining method. 2. In a wire electrical discharge machining device configured to perform electrical discharge machining by generating electrical discharge between an electrical discharge wire and a workpiece, a wire formed by the movement of a non-linear line of the workpiece A wire locus regulating means having substantially the same shape as the surface to be machined is provided, a single discharge wire is spirally wound around the wire locus regulating means, and electric discharge is caused while the discharge wire is moved along the spiral locus. 1. A wire electrical discharge machining device characterized in that a wire electrical discharge machining device is configured to perform electrical discharge machining by generating a wire. 3. The wire electrical discharge machining apparatus according to claim 2, wherein a spiral wire trajectory regulating groove is provided on the outer periphery of the wire trajectory regulating means.