JPH0215921A - Wire-cutting electric discharging machine - Google Patents

Abstract

PURPOSE:To greatly reduce the input operation to an NC controller of a wire- cutting electric discharging machine, for setting a wire cutting passage and improve the operability by connecting a digitizer which generates plots on a display as X-Y coordinate values, to the NC controller. CONSTITUTION:A digitizer 3 has an X-Y plane screen face and sends coordinate values (X, Y) of dots plotted along the outline of a model or a paper pattern to the NC controller 2 of a wire-cutting electric discharging machine. In this NC controller 2 the coordinate values (X, Y) of the plotted dots sent from the digitizer as wire-processing passage data are stored sequentially in a memory. Based on the stored data, the wire-cutting electric discharging machine 1 is driven and controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a wire-cut electric discharge machining apparatus that cuts a workpiece by utilizing an electric discharge phenomenon between a wire and a workpiece.

In a wire-cut electric discharge machine equipped with a prior art NC11IIIIIIiiiI, it is necessary to program and input the machining path of the wire relative to the workpiece. Conventionally, programming for this purpose was based on a machining drawing in which precise numerical values were entered, and using a prepared programming language such as G code or M code to determine the position of points on the drawing and whether the two points were straight lines or arcs. The basic method is to specify and input each interpolation method one by one.

Therefore, when creating a manufactured product from a model, paper pattern, or actual object, it takes time to first create the drawings, such as measuring dimensions and drawing, and then specifying the positions of the necessary points and the interpolation method. It is necessary to read and input numbers and symbols on drawings, and if there are many points to be input, it is time-consuming and can lead to input errors. For example, even if the shape is simple, such as an egg-shaped cam, in order to make the interpolation method satisfactory with a straight line or circular arc, it is necessary to specify the position of the points and the interpolation method, even if very high precision is not required. becomes a considerable number.

On the other hand, when machining a simple shape and allowing an error of several microns, there is no particular meaning in interpolating between two points of the machining figure one by one by distinguishing between a straight line or a circular arc. If it is divided appropriately into small sections, it is possible to obtain a fully satisfactory processed product even if all the interpolation methods are linear interpolation.

Problems to be Solved by the Invention It is an object of the present invention to provide a wire-cut electric discharge machining apparatus that can obtain and process a wire machining path directly from a model, paper pattern, or actual object.

Means for Solving the Problem A digitizer is connected to a wire-cut electrical discharge machine equipped with an NCi, Ill device.

The digitizer has an X, Y plane screen, and the position of a point plotted on this screen is expressed as a coordinate value (X).

It has a function to output as Y).

The digitizer calculates the coordinate values (X, Y) of points plotted along the outline of the model, paper pattern, etc. placed on the X, Y plane.
Output to the NCIJ ml device.

The NG control device sequentially stores the coordinate values (X, Y) from the digitizer regarding the plot points as wire machining path data in a memory, and controls the wire cut electrical discharge machine based on this data.

Embodiment In FIG. 1, reference numeral 1 denotes a wire electrical discharge machine equipped with an NC control device 2. In FIG. A digitizer 3 is connected to the NC control device 2.

The digitizer 3 has an X, Y plane screen on which orthogonal coordinates (digitizer coordinate system) are set, and the position of a point (plot point) plotted with a special pen on the screen is expressed as coordinate values (X, Y). This coordinate value can be output directly to a part of the memory of the NG control device by operating the output button provided on the dedicated pen at the same time as plotting.

The digitizer 3 of the embodiment employs a pressure-sensitive resistance system in which conductive rubber is arranged in a grid to detect changes in resistance due to pressure.

Regarding the method of inputting machining conditions, the NC control device 2 has a digitizer usage mode in addition to an NG tape usage mode, a cannibal program usage mode stored in memory, and in this mode, when a plot point is input from the digitizer 3, the next It has a function of adding a G code indicating that linear interpolation is performed between the plot points and sequentially storing them in the RAM.

Note that the coordinate values (X, Y) stored in the RAM are input after being converted from the coordinate system of the digitizer 3 to the machine coordinate system of the wire-cut electrical discharge machine 1.

The present invention relates to the NC11JtLD equipment N2 of the wire electrical discharge machine 1.
It is characterized in that it is an integrated wire electrical discharge machining apparatus in which a digitizer 3 is attached to the digitizer 3.

The cross-sectional shape shown in Fig. 2 (a) is the target machining figure Q)
When processing parts from a model, the NC control device 2 is switched to the digitizer use mode, the model is placed on the X and Y screens of the digitizer 3, and a plot of the outer circumference of the model is taken with a special pen.

In this case, first, an appropriate point A (a, b) is determined.

Since this point A is the starting point in the actual wire cutting process, it must be determined in consideration of the actual machining conditions, such as the placement of the machining figure Q with respect to the workpiece 4 (Figure 2 (b)). .

Next, move around the outer periphery of the model (machined figure Q) in the shortest distance possible.
After reaching point B), trace the outer periphery of the model as shown by the arrow in the figure and plot it with a special pen, and each time, operate the output button to make a full circle as accurately as possible.

In this case, a straight line part of the processed figure is plotted without missing one end and the other end of the part, and a curved part is plotted with smaller intervals as necessary.

In the digitizer use mode, the NC control device 2 converts the coordinate values of each plot point input from the digitizer 3 into the machine coordinate system, adds a G code that is a straight line between two points (linear interpolation), and stores it in the machining condition RAM. Store sequentially. As a result, the NC control device 2 has obtained the machining conditions regarding the machining figure Q (FIG. 2 (b)), so it ends the input in the digitizer mode and enters the machining execution mode. The operation of the NC control device 2 in the machining execution mode is the same as in the conventional case, and machining conditions are sequentially read out from the machining condition RAM to control the wire-cut electric discharge machine and perform machining.

However, in reality, it is necessary to consider the wire diameter and the amount of uncut material for finishing, and the wire diameter correction value S
NCll1 sets the command as to whether to provide the left or right uncut side as an offset m to the machining figure Q in advance.
1 to the control device 2, and at the same time as the input of the machining/figure Q is completed, the wire machining path P is opened as shown in Fig. 2 (b).
is now set.

That is, the NG control til+ device 2 sets the digitizer coordinate point A as the processing start point and the machine coordinate reference point R as the origin so that the wire position moves relatively along the wire processing path P. Drives the X and Y tables of the wire cut electrical discharge machine.

Although the input of the wire machining path P to the NG control device has been mainly explained above, other conditions required for wire cut electric discharge machining, such as wire feed speed, wire tension, machining fluid pressure, etc., are the same as in the conventional case.

The digitizer 3 is not limited to the above-mentioned embodiments, but may also be a magnetostrictive type that detects coordinates using the phase difference of electromagnetic waves.

The machining figure Q to be plotted on the digitizer 3 is
It can also be set by projecting the cross-sectional shape of the actual part or by arranging a paper pattern.

In addition, if a programming device is used between the digitizer and the NC11:11, and this programming device has a function to automatically create a program for taper machining by inputting the shape of the upper and lower surfaces of the workpiece, the upper and lower surfaces of the workpiece can be By inputting the machining figure in the same manner as described above, it is also possible to perform a certain type of taper machining (in which the slope angle is automatically determined).

Effect of invention is NG! The input work for the wire processing path into the 11111 device is greatly reduced, and input errors are eliminated, improving work efficiency.

There are no processing failures due to human error.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration, and FIGS. 2(a) and 2(b) are plan views for explanation. 1... Wire cut electric discharge machine, 2... NG control device, 3... Digitizer, 4... Work.

Claims (1)

[Claims] A wire-cut electrical discharge machining device, characterized in that a digitizer for outputting plot points on a screen as X and Y coordinate values is connected to an NC control device of the wire-cut electrical discharge machine.