| 摘要 |
The invention relates to electrical discharge milling machines using tool electrodes subject to longitudinal wear. The inventive discharge milling machine is equipped with a numerical controller executing at least one control cycle for compensating the wear considering the following steps:
(a) determining the volume Q eroded by each discharge,(b) calculating the distance s travelled by the tool from one effective discharge to the next,(c) calculating the actual eroded linear volume M [m3/m] for at least one effective discharge, M forming a measurement sample from the values Q and s,(d) comparing said sample M with the corresponding set value C to generate an error D=C−M [m3/m], and(e) calculating and transmitting a command by the numerical controller intended to reduce this error D during the following cycle or cycles. |
| 主权项 |
1. Electrical discharge milling machine comprising tool electrodes of elongate shape and of constant cross section, wherein the tool electrodes carry out machining at their ends and are subject to longitudinal wear, said machine being equipped with:
(a) an erosive discharge generator, (b) a rotating spindle with a mandrel, (c) a numerical controller, (d) a set of motorized axes controlled by the numerical controller, (e) a device for measuring the length of the tool outside the machining process, (f) a tool path generator interfaced with the numerical controller, which divides the workpiece into a stack of successive layers to be machined and define one or more paths for the sweep of the tool in each layer, and (g) a post-processor acting as a set value generator, interfaced with the numerical controller or integrated therein; wherein the post-processor generates a file of set values C [m3/m] equivalent to the set linear volume which has to be eroded from the workpiece per unit of length of the tool movement on the path, interacting with a first controller which executes a repetitive control cycle composed of at least the following steps: (h) determining the volume Q eroded by each discharge, (i) calculating the distance s travelled by the tool from one effective discharge to the next, (j) calculating the actual eroded linear volume M [m3/m] for at least one effective discharge, M forming a measurement sample from the values Q and s, (k) comparing said sample M with the corresponding set value C to generate an error D=C−M [m3/m], and (l) calculating and transmitting a command by the numerical controller intended to reduce this error D during the following cycle or cycles. |
