JPS59227330A - Taper machining device for wire electric discharge machine - Google Patents

Abstract

PURPOSE:To prevent the occurrence of unnecessary infeed to a work at a shifting point between a curve and a straight line, by controlling a machining table and an upper wire guide for the duration from the start point to the end point of an arc in time of taper machining for a circular part of the work by means of numerical control. CONSTITUTION:When a work 2 is machined, projection length to the horizontal surface of a segment connecting a shifting point of two points in a curve and a straight line at the moving locus of a wire electrode on a surface inclusive of an upper wire guide 3 and a surface of a machining table 1 is found upon its similitude development. And, there is provided with a control device 9 having a program which inputs a moving start point radius, a moving end point radius and a radius of curvature in the moving start point on the surface of the machining table 1 on the surface inclusive of the upper wire guide 3, controlling an X-axis control part 4, a Y-axis control part 5, a U-axis control part 6 and a V-axis control part 7. Thus, unnecessary infeed to the work can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a wire-cut electric discharge machining method that controls a machining table and an upper wire guide between the start point and the end point of an arc in a section that tapers an arc portion of a workpiece by numerical control. The present invention relates to a taper processing device for a machine.

Conventionally, there has been a device of this type as shown in FIG. In the figure, (1) is the processing table, (2) is the workpiece, (3) is the upper guide, (4) is the X-axis control unit, (5) is the
) are the Y-axis control unit, and the X-axis and
Drive in the Y-axis direction. (6) is the U-axis control section, (7)
The Y-axis control section drives the upper guide (3) in the U-axis and Y-axis directions, respectively. (8) is fixed by the lower wire guide, (9) is the X-axis control section (4), the Y-axis control section (
5), a numerical control device that controls the U-axis control section (6) and the Y-axis control section (7), where 01 is a wire electrode.

Next, the operation will be explained. Figure 2 shows the lower guide (8)
FIG. 3 is a diagram showing the command values of the numerical control device (9) at respective distances between the processing table (1), the workpiece (2), and the upper guide (3) i with reference to . In the figure,
θ is the taper angle at 0%), α force to M is the distance based on the lower guide (8), that is, (111 is the processing table (1) to t″CQ (b) is the workpiece (2) The program execution value which is the machining bottom surface (height of the cutting edge)
网 represents the distance to the speed command height which is the midpoint of the machining thickness t of the workpiece (2), and α4 represents the distance to the upper designated height which is the machining top surface of the workpiece (2).

Figure 6 shows the 8-movement locus at a distance of 0 from the lower guide (8) to the siprogram execution value height in the program of the numerical control device (9), and the taper at a distance of 0 from the upper specified height. It is a figure showing an offset locus.

In the figure - Ca1 (l), (g) is the distance to the program execution value height (movement trajectory in 琲, 0 scratches.

(20a), (20b), (20c), H, (22
a), (22b), (22c) and (to) are taper offset trajectories at the distance α◆ to the upper specified height, and the locus α force starts from the OI shown and ends at 08,
The trajectory Q center is set at O3 as the starting point and 04 as the ending point, and the processing is performed by starting and ending at the starting point and the ending point at the same time.

In this case, the arcuate motion of the trajectory (b) is a combination of the movement of the processing table (1) and the movement of the upper wire guide (3) in Fig. 1, so the control device (9) and the upper wire guide , - The command to (3) moves along the trajectory Q. In addition, since it operates with the control N command as described above, in order to shift from the linear movement trajectory (111) to the arc movement trajectory QO-\, the starting point is the trajectory (20 slides), (2(l)
b) and (20c) and return to point 907, which becomes the starting point of the trajectory Qρ. In the same way, from the circular arc trajectory (c) to the straight trajectory)
The button that moves to moves at 904 points following the trajectories (22a), (22b), and (22c).

The taper machining device of the conventional wire-cut electric discharge machine is configured as described above, so when the wire electrode moves from a straight line to a circular arc or from a circular arc to a straight line, depending on the machining shape of the workpiece, 1 is an extra cut. It had a drawback that required processing.

The present invention has been made to eliminate the above-mentioned conventional drawbacks, and embodiments of the present invention will be described below with reference to the drawings. FIG. 4 is a diagram showing a movement locus of the distance (2) from the lower guide (8) to the cibragram execution value height in FIG. 1 according to the present invention, and a taper offset locus at the distance m04 to the upper specified height. Figure (The locus at noodle distance (b) is aQ.

a'I), α樟, and the trajectory at distance α is (b)
, (ho), ni). FIG. 5 is a three-dimensional diagram showing a reduced scale of FIG. 4 above. Also, as shown in Figures 4 and 5 (
b) is the intersection (0,) of the locus αQ and the locus α force, and the locus α
A vector heading toward the intersection (OX) of the trajectory (C) and the trajectory (C) with a taper offset applied to Q and the trajectory α force, respectively,
In addition, (goods) is a vector from the intersection (08) of the trajectory af) and the trajectory α→ to the intersection (04) of the trajectory α) and the trajectory (c) with taper offsets at the time of the trajectory be. Now, in Fig. 5, (0-0) is the taper axis, (slope - x (taper angle), (o+), (o
x), (ox) and (04) indicate points of the same sign in FIG. Further, in the following explanation, other symbols not shown in the drawings are the same as those in FIG. 1. First, the curve from (0,) to (os) is the locus (b), and from (O7)
The curve leading to (oa) shows ) in the locus. Here, if we develop the vector (b) into the movement of the machining table (1) and the upper guide (3), we can see that the machining table (1) and the upper guide (3) driven by the command υ from the control device (9) The movement locus may not necessarily be an arc depending on the shape to be machined. However, the shaded area in the figure is a similar triangle divided around the intersection (P) of the processing table (1) surface and the taper axis (0-0), so the vector is Find the starting radius of the arc on the processing table (1) surface by performing similar expansion on the processing table (1) surface centered on .
Furthermore, the vector (c) is similarly expanded and the processing table (1
) Find the end point radius (g) of the arc on ). Similarly, the starting point radius 0 and the ending point radius of the arcuate movement of the upper guide (3) can be determined.

Next, since the time to move one trajectory θf and the time to move one trajectory (b) are the same, at any time t:
The processing table (1
) The radius of curvature at an arbitrary time t from the starting point to the end point on the locus 0f)K of the surface of the processing table (1) can be found by similar expansion in the same way as the method used to find the arc origin radius (C) on the surface (1). In a similar manner, find the radius of curvature (c) at an arbitrary time t from the starting point to the ending point in the locus of the surface including the upper wire guide (3).

The starting point radius, ending point radius and arbitrary time t found above
The program obtained by inputting the radius of curvature at rr
Ynpa U, V, X and Y axis drives (6),
(7), (4), and (5) move the upper wire guide (3) and the processing table (1) for processing, so that the locus of the wire electrode a1 changes from a straight section to a curved section, or Unnecessary cuts into the workpiece (2) K at the transition point from the curved section to the straight section can be avoided.

As described above, according to the present invention, it is possible to easily detect the transition point between a curve and a straight line in tapered curve machining without significantly changing the processing capacity of circular interpolation (constant radius) that conventional numerical control devices have. To obtain a taber machining device for an electrical discharge machine that does not make unnecessary cuts to a workpiece.

[Brief explanation of drawings]

Fig. 1 is a diagram showing the configuration of the Taber machining device of a wire-cut electric discharge machine, Fig. 2 is a diagram showing the positional relationship of the upper wire guide, workpiece, machining table, and lower wire during Taber machining, Fig. 6 4 is a diagram showing the trajectory of the upper wire guide and the wire electrode on the processing table surface by conventional taper processing, and FIG. 4 shows the upper wire guide and the wire electrode on the processing table surface according to one embodiment of the invention FIG. 5 is a diagram showing the locus of FIG. 4 as a main part, as viewed diagonally from the upper wire guide toward the cutting table surface. (1)...Processing table, (3)...Upper wire guide, (9)...Control device, OQ...Wire electrode,
aQ, θ, (II...-trajectory of machining table (1), ni), ni), (c)...''trajectory of movement of two-part wire guide, ni), (c)...movement p6 locus aI, θ force,
Projection of the line segment connecting the transition point between the straight line and the curve in (c), (c), (c), OI... radius of the starting point of movement on the processing table surface and end point of movement radius, 0
η, (b)...radius of the movement start point and radius of the movement end point on the plane including the upper wire guide, (b)...radius of curvature of the movement trajectory θ, (b)...radius of curvature of the movement trajectory () . Agent Masuo Oiwa 01 Q -0 Procedural amendment (spontaneous) July 48, 1980 To the Commissioner of the Japan Patent Office 1, Indication of the case Patent application No. 58-1°5085 No. 2
, Name of the invention Taper processing device for wire electrical discharge machine 3, Person making the correction Representative Hitoshi Katayama Department 4 Address of the agent Mitsubishi Electric Corporation, 2-2-3 Marunouchi, Chiyoda-ku, Tokyo & Contents of the correction

Claims (2)

[Claims] (1) In a wire electric discharge machine, the projected length of a line segment connecting two transition points between a straight line and a curved line in the movement trajectory of the wire electrode on the surface including the upper wire guide and the processing table surface on the horizontal plane. A control device is provided with a program in which a movement starting point radius, a movement ending point radius, and a radius of curvature from the movement starting point to the ending point on the surface including the upper wire guide and the processed table surface, which are obtained by similar expansion, are input. Taper processing device for wire electrical discharge machine. (2) The machine for wire electrical discharge machining according to claim 1, characterized in that the radius of curvature from the starting point to the ending point is determined using a relationship of a linear function.