JPH0569237A - Electric discharge generation processing method - Google Patents

Abstract

(57) [Summary] [Object] It is an object of the present invention to provide an improved electric discharge generating and machining method with a simple control method and easy electrode production. According to the present invention, a work-piece 40 placed on a processing table and a rod-shaped electrode 41 attached to a holding device for an electrode spindle 10.
A method of electric discharge machining in which and are relatively moved to perform electric discharge machining is to form a rod-shaped electrode 41 into a rod-shaped body having an L-shaped or J-shaped circular cross section, and to rotate the shaft center of the electrode main shaft 10 and The rod-shaped electrode 41 is attached so that the vertical axes thereof are aligned with each other, and the movement locus of the vertical axis of the rod-shaped electrode 41 is controlled by feeding in three-dimensional directions of X, Y, and Z axes from the machining start point, and during the feeding process, the rod-shaped electrode 41 is By controlling the rotation angle of the C-axis rotating around the vertical axis center of the rod-shaped electrode 41, the workpiece 40 and the rod-shaped electrode 41 are relatively moved to reach the processing end point, and the rod-shaped electrode 41
Is controlled so that the enveloping surface of the workpiece coincides with the outer shape of the convex shape created on the workpiece 40, and unnecessary portions are collectively removed from the workpiece as a three-dimensional block to create a convex shape.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric discharge generating method for performing electric discharge machining by using a rod-shaped electrode having a simple shape to relatively move the workpiece and the electrode, and particularly to the workpiece. The present invention relates to an electric discharge generating method for generating and processing a convex outer shape portion.

[0002]

2. Description of the Related Art In the conventional electric discharge machining method, a rectangular rod electrode is used to control the movement of the electrode in the three-dimensional directions of X, Y and Z axes, and the rod electrode is centered on the intersection of two sides of the electrode cross section. There is known an electric discharge generating machining method in which a wire is turned (for example, Japanese Patent Publication No. 47-48557). Further, the electric discharge generating / machining apparatus uses a loop-shaped electrode adapted to the machining shape, and controls the movement of the electrode in the three-dimensional directions of the X, Y, and Z axes, and the electrode can be swung laterally. An electric discharge generating / machining device is known (for example, Japanese Patent Laid-Open No. 55-55).
-96231).

[0003]

These methods and devices are difficult to control in order to move the workpiece and the electrode relative to each other, and the used electrode is a loop-shaped electrode adapted to the processed shape to be obtained. However, it is difficult to manufacture the electrode, and further, there are drawbacks such as interference when processing a narrow portion of the concave shape.

Therefore, an object of the present invention is to provide an improved electric discharge generating method for compensating for the above-mentioned conventional drawbacks, improving the control method and the electrode production, and forming and machining a convex outer shape portion on a workpiece. Is provided.

[0005]

The gist of the present invention is to use an L-shaped or J-shaped rod-shaped electrode as a standard electrode, and move the movement locus of the center of the vertical axis of the electrode in the three-dimensional directions X, Y, Z from the machining start point. And by controlling the rotation angle around the C axis that rotates about the vertical axis of the electrode during the feeding process, the workpiece and the electrode are relatively moved to reach the processing end point. , The envelope surface of the electrode is controlled so as to match the outer shape of the desired convex shape to be created on the work piece so that the three-dimensional blocks are collectively removed from the work piece, and the convex shape is created. This is an electric discharge generation processing method.

That is, according to the present invention, there is provided an electric discharge generating method for performing electric discharge machining by relatively moving a workpiece placed on a machining table and a rod-shaped electrode attached to a holding device for an electrode spindle. The rod-shaped electrode is formed into a rod-shaped body having an L-shaped or J-shaped circular cross section, and is attached so that the axial center of the rotatable electrode main shaft and the vertical axis center of the rod-shaped electrode coincide with each other. The movement locus is controlled by feeding in the three-dimensional directions of X, Y, and Z axes from the machining start point, and in the feeding process, the rotation angle of the C axis that rotates about the vertical axis center of the rod-shaped electrode is controlled to control the object. The workpiece and the rod-shaped electrode are moved relative to each other to reach the processing end point, and the envelope surface of the rod-shaped electrode is controlled so as to match the outer shape of the convex shape created in the workpiece, and thus the workpiece. To collect all unnecessary parts as solid blocks Discharge generating process method to creating a removed by Shi convex shape is provided. The method of the present invention will be described below with reference to the drawings.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a mechanical diagram of an example of an apparatus for carrying out the electric discharge generating and machining method of the present invention, wherein 1 is a workpiece and 2 is a rod-shaped electrode having an L-shaped or J-shaped circular cross section. is there. An X-axis and Y-axis feed mechanism 4 is provided below the column 3. The feed mechanism 4 has a cross guide surface structure so that the workpiece can be fed in the X-axis and Y-axis directions, and an X-axis feed motor 5 and a Y-axis feed motor 6 are attached to each.

A Z-axis feed mechanism is provided above the column 3, and the Z-axis feed mechanism 7 has a guide structure capable of feeding the electrode 2 in the Z-axis direction. Is attached. An electrode spindle head 9 is attached to the movable portion of the Z-axis feed mechanism 7, and an electrode spindle 10 is provided therein. The electrode 2 is attached to the lower part of the electrode main shaft 10, and the upper part of the electrode main shaft 10 is connected to the C-axis drive motor 11.

The electrode main shaft 10 is rotatably supported around its axis, and its rotation angle is controlled by a C-axis drive motor 11. A rotation axis around the axis of the electrode main shaft 10 is referred to as a C axis. The numerical controller 12 issues appropriate drive signals to the X-axis feed motor 5, the Y-axis feed motor 6, the Z-axis feed motor 8 and the C-axis drive motor 11 on the basis of the given numerical control information, and the electric discharge machine. X
By driving the axes, the Y axis, the Z axis, and the C axis, the workpiece 1 and the electrode 2 are relatively moved to perform electric discharge machining.

Although not shown in the figure, this electric discharge machine is equipped with necessary devices as an electric discharge machine such as a pulse generating power supply device for electric discharge and a machining fluid supply device. FIG. 2 shows a rod-shaped electrode having an L-shaped circular cross section used in the present invention. A round rod copper material having a diameter of 1.5 mm is bent at a right angle,
The central axis 21 of the vertical axis portion 20 is attached to the electrode main shaft 10 so as to coincide with the rotation axis around the axis of the electrode main shaft 10 in FIG. 1, that is, the C axis. The horizontal axis portion 22 of the L-shaped rod-shaped electrode has a value L that is appropriately set according to the three-dimensional shape such as the convex shape to be obtained.

Next, the electric discharge generating machining method of the present invention will be described first with respect to the concave-shaped machining which is the premise of the invention, and then with respect to the convex-shaped machining method according to the present invention. Explained.

FIG. 3 is an X, Y, Z plan view showing a contour of a processing example, which is an example of processing a concave shape having a certain depth in the Z-axis direction. FIG. 4 shows command data to be input to the numerical control device 12. The minimum command unit for the X, Y and Z axes is 0.001 mm, and the minimum command unit for the C axis is 0.001 degree. Further, the relationship between the movement command data of each axis and the movement direction of each axis is such that when the value of the command data is positive, the movement is in the directions of the + X, + Y, + Z arrows shown in FIG.

FIGS. 5 and 6 show the movement and rotation of the L-shaped rod with respect to the workpiece when the numerical control unit interpolates and controls the X, Y, Z and C axes based on the command data of FIG. It is the figure which projected the state of the change of above on the X and Y plane. FIG. 5 shows a case where the horizontal axis portion 22 of the L-shaped rod-shaped electrode is short, and FIG. 6 shows a case where it is elongated. Reference numeral 30 is a movement locus of the central axis 21 of the vertical axis portion 20 of the L-shaped rod electrode, and a large number of elliptical figures 31 are L at that time.
The orientation of the horizontal axis portion 22 of the shaped rod electrode is illustrated.
The movement locus 30 is a locus which is interpolated and controlled by the command data relating to the X axis and the Y axis of the command data shown in FIG. 4, and its shape dimension is 0.8 inside the contour shape shown in FIG.
mm (a value obtained by adding a discharge gap length of 0.05 mm to the radius 0.75 mm of the vertical axis portion 20 of the L-shaped rod-shaped electrode).

Next, the processing sequence will be described with reference to FIG. 5 according to the order of the block of the command data in FIG. As an initial setting, the horizontal axis portion 22 of the L-shaped rod electrode is set to be parallel to the Y axis in FIG. 1, and the tip portion 23 of the electrode is set to face the positive direction of the Y axis. That is, the center axis 21 of the vertical axis portion 20 of the L-shaped rod-shaped electrode is placed at point A in FIG. 5, and the tip portion 2 of the same electrode is placed at point A '.
Initialize so that 3 is set.

First, the numerical control device 12 is started up, and as shown in FIG.
When the command data of (1) is executed, only the Z axis moves in the negative direction (downward) in the block (1), and the horizontal axis portion 22 of the L-shaped rod electrode is machined until the predetermined depth of the workpiece is reached ( A-A 'in FIG. 5). In block (2), move only the Y-axis,
The position of BB 'in FIG. 5 is reached. In the block (3), only the X axis is moved to reach the position C-C '. Block (4)
Then, two-axis circular interpolation of X and Y is performed to reach the position D-D '. In the block (5), the horizontal axis portion 2 of the L-shaped rod electrode
Only the C-axis rotates -90 degrees so that the direction of 2 becomes the right angle to the next linear locus and reaches the position of DD '. In the block (6), only the Y-axis is moved and In the block (7), only the C-axis is -48. So that the horizontal axis portion 22 of the L-shaped rod electrode faces the center point of the next arc.
It rotates 888 degrees and reaches the position of EE ". In block (8), X and Y 2-axis circular interpolation and C-axis rotation interpolation are simultaneously performed in relation to each other. The central axis 21 of the vertical axis portion 20 of the L-shaped rod electrode is circularly interpolated.
C axis is -82.2 in synchronism with the movement from point E to point F.
It rotates only 24 degrees and reaches the position of FF '. In the block (9), like the block (5), only the C-axis is rotated so that the direction of the horizontal axis portion 22 of the L-shaped rod-shaped electrode is perpendicular to the next straight line locus, and reaches the position F-F ". Block (1
In 0), only the Y-axis moves and reaches the position G-G '.
In the block (11), the same control as in the block (8) is performed to reach the position of H-H '. In the block (12), only the X axis is moved to reach the position of BB ', and the contour processing is finished. The block (13) and below are for returning the electrode to the processing start position.

If the above-mentioned processing is performed, as is apparent from FIG. 5, the horizontal axis portion 22 of the L-shaped rod electrode does not go into the outside of the locus 30 of the central axis 21 of the vertical axis portion 20 of the electrode. As for the side surface shape of the work piece after machining, the desired concave shape shown in FIG. 3 is obtained except for the inner corner portions. Further, as shown in FIG. 6, an L-shaped rod electrode (see FIG.
If the length L of the horizontal axis portion 22 of (see) is sufficiently large, the bottom surface of the contour shape to be obtained is completely processed and removed over the entire surface. Then, a desired three-dimensional concave portion is processed in the workpiece. In the above processing example, the electrode shape is an L-shaped rod shape, but if the electrode shape is a J-shaped rod shape, the bottom surface of the concave portion is formed into a concave curved surface.

The above-described processing example is a processing method in the case of forming a concave recessed portion in the workpiece, but a processing embodiment in the case of forming a convex shape in the workpiece according to the present invention is shown in FIG. To FIG. FIG. 7 shows the progress of the processing method of the present invention. 40 is a prismatic work piece having a predetermined height, 41 is an L-shaped rod electrode at the processing start position, and 41 'is during the processing. A certain L-shaped rod electrode, 42 is an L-shaped rod electrode 41
The slits processed and removed in the vertical axis portion of the above, and the reference numeral 43 represents the slits processed and removed in the horizontal axis portion of the L-shaped rod electrode 41.

FIG. 8 shows changes in the movement and rotation of the L-shaped rod electrode with respect to the workpiece when the numerical control device interpolates and controls the X, Y and C axes based on command data (not shown). It is the figure which projected the situation on the X and Y plane.
In the figure, reference numeral 44 denotes a locus of movement of the central axis of the vertical axis portion of the L-shaped rod electrode 41, and a number of elliptical figures 45 show the orientation of the horizontal axis portion of the L-shaped rod electrode 41 at that time. And 46 is an XY cross-sectional view of the prismatic work piece 40, and the processing sequence starts from the position aa ′ and then b
-B ', cc' ... ff ', bb'. FIG. 9 is a sketch of the machined part. As shown in FIG. 8, if the C-axis rotation operation is always performed at the same time as the X and Y-axis movements and only the C-axis rotation operation is not performed independently, the vertical shape of the L-shaped electrode is reduced. Since the relative movement between the shaft portion and the workpiece does not become stagnant during the machining, the machining accuracy of the side surface of the workpiece is improved. As described above, according to the processing method shown in the second embodiment, a punch with a seat for press processing, which was difficult to process with the conventional wire-cut electric discharge machine, can be processed in a single step and extremely efficiently. is there.

[0019]

As is apparent from the above, according to the present invention, not all the shapes to be removed from the workpiece are pulverized and removed by electric discharge machining, but only the three-dimensional convex contours are removed. Since it is a method that requires less processing energy, processing efficiency is good. Further, since the electrode has a simple curved shape, not only the electrode can be easily manufactured, but also the processing waste can be easily discharged, so that the processing speed can be increased.

Furthermore, since the electrode shape is not a loop shape, even when processing a narrow part, the electrode does not interfere with the non-processed part and the workable range is expanded.

[Brief description of drawings]

FIG. 1 is a mechanism diagram of an apparatus for carrying out an electric discharge generating and machining method according to the present invention.

FIG. 2 is an example view of an L-shaped rod electrode.

FIG. 3 is an X, Y plan view showing a contour of a concave-shaped processing example which is a premise of the method according to the present invention.

FIG. 4 is command data to be input to the numerical control device.

FIG. 5 is a diagram in which the state of movement and rotation of the L-shaped rod electrode with respect to the workpiece is projected on the X and Y planes.

FIG. 6 is a diagram in which the state of movement and rotation of the L-shaped rod electrode with respect to the workpiece is projected on the X and Y planes.

FIG. 7 is a perspective view three-dimensionally showing a process in the process of processing the convex-shaped component according to the present invention.

FIG. 8 is a plan view in which the state of movement and rotation of the L-shaped rod electrode with respect to the workpiece is projected on the X and Y planes.

FIG. 9 is a sketch drawing of a convex shaped component processed by the processing method of the present invention.

[Explanation of sign]

 1 ・ ・ Workpiece 2 ・ ・ L-shaped rod electrode 4 ・ ・ X-axis and Y-axis feed mechanism 5 ・ ・ X-axis feed motor 6 ・ ・ Y-axis feed motor 7 ・ ・ Z-axis feed mechanism 8 ・ ・ Z-axis feed Motor 10. ． Electrode spindle 11 ... C-axis drive motor 12 ... Numerical control device

Claims (1)

[Claims] 1. An electric discharge generating method in which electric discharge machining is performed by relatively moving a workpiece placed on a machining table and a rod-shaped electrode attached to a holding device for an electrode spindle, wherein the rod-shaped electrode is L-shaped or The rod-shaped body is formed into a J-shaped rod having a circular cross section, and is attached with the axial center of the rotatable electrode main shaft aligned with the vertical axis center of the rod-shaped electrode. X,
The workpiece and the rod-shaped electrode are controlled by controlling the feed in the three-dimensional directions of the Y and Z axes and controlling the rotation angle of the C-axis that rotates around the vertical axis center of the rod-shaped electrode in the feeding process. The relative movement is made to reach the processing end point, and the envelope surface of the rod-shaped electrode is controlled so as to match the outer shape of the convex shape created in the workpiece, and unnecessary portions from the workpiece are collectively formed as a solid block. An electric discharge generating method, characterized in that it is removed to create a convex shape.