CN109352103B

CN109352103B - Large-current multi-time cutting method for high-speed reciprocating wire-moving electrospark wire-electrode cutting

Info

Publication number: CN109352103B
Application number: CN201811356059.9A
Authority: CN
Inventors: 邱明波; 邹尧; 刘志东; 邓聪
Original assignee: Jiangsu Nanhang Laichuang Technology Co ltd; Nanjing University Of Aeronautics And Astronautics Wuxi Research Institute
Current assignee: Jiangsu Nanhang Laichuang Technology Co ltd; Nanjing University Of Aeronautics And Astronautics Wuxi Research Institute
Priority date: 2018-11-14
Filing date: 2018-11-14
Publication date: 2021-07-30
Anticipated expiration: 2038-11-14
Also published as: CN109352103A

Abstract

The invention discloses a high-current multi-time cutting method for high-speed reciprocating wire-cut electrospark wire-electrode cutting, which adopts four times of cutting, namely 'cutting one, clearing one and repairing two', namely, the high-efficiency cutting forming is carried out through the first time of high current, the cutting-clearing cutter for the second time is used for cutting a workpiece with zero trimming amount or minimum trimming amount by adopting the wire-feeding speed and the processing energy which are more than half of the cutting speed and the processing energy for the first time, so as to reduce the residual corrosion products between electrodes and eliminate the deformation of the workpiece, and then the high-speed trimming cutting of the third time and the fourth time of cutting is carried out by adopting the narrow-pulse-width high-peak current, so that the processing precision and the surface quality of the workpiece are further improved, and the purposes of high cutting efficiency and high processing quality are achieved.

Description

Large-current multi-time cutting method for high-speed reciprocating wire-moving electrospark wire-electrode cutting

Technical Field

The invention relates to a wire-cut electric discharge machining method, in particular to a high-speed reciprocating wire-feed wire-cut electric discharge machining method, and specifically relates to a large-current multiple-cutting method for high-speed reciprocating wire-feed wire-cut electric discharge machining.

Background

The multiple cutting is a fundamental means for improving the machining precision and the surface quality of the wire cut electrical discharge machining, the rough machining and the finish machining are separately carried out, and the contradiction between rapidness and good performance is solved by two machining procedures of main cutting and trimming. At present, three times of cutting (cutting and repairing) are adopted for reciprocating wire-cut electric spark wire cutting, generally, the first time of cutting forming is adopted, the second time of cutting improves the machining precision, and the third time of cutting improves the surface quality of a machined workpiece.

The average machining current of the conventional reciprocating wire-cut electrospark wire-electrode cutting is generally 4-6A, and the once cutting efficiency is stabilized at 100-150mm for a long time²The comprehensive efficiency of the cutting for three times (cutting for one time and repairing for two times) is generally 80-100mm²And/min. In recent years, with the popularization and use of high-frequency intelligent pulse power sources and composite working fluids,the average cutting current reaches 10-15A, and the maximum efficiency of one-time cutting exceeds 300mm²The method is mainly characterized in that the energy during one-time cutting is greatly increased, the profile precision, the surface quality and the interelectrode state of a cut workpiece are changed essentially, if small-energy trimming is carried out according to a conventional multiple-time cutting method, the comprehensive efficiency of multiple cutting cannot be improved, and the purpose of improving the machining precision and the surface quality by multiple cutting is difficult to achieve. Therefore, it is necessary to adopt a novel trimming method for high-speed trimming after high-current high-efficiency cutting.

Disclosure of Invention

The invention provides a high-current multi-time cutting method for high-speed reciprocating wire-cut electric spark wire cutting, aiming at the problems of poor interelectrode state, low profile precision and large material deformation after high-current high-efficiency cutting of high-speed reciprocating wire-cut electric spark wire cutting, which influence the cutting efficiency and the machining quality of subsequent trimming and cutting.

In order to achieve the purpose, the invention adopts the following technical scheme:

a high-current multiple cutting method for high-speed reciprocating wire-cut electrospark features that four times of cutting, cutting-cleaning-repairing-cutting, are used, that is, the first high-current high-efficiency cutting is used for shaping, the second cutting is performed by cutting the workpiece at a speed more than half of the wire-feeding speed and energy greater than the first cutting, and the cutting-cleaning is performed to reduce residual corrosion products between electrodes and eliminate deformation of workpiece.

Further, the zero or minimal trim delta for the second cut is in the range of 0-0.02 mm.

Has the advantages that:

1. the invention solves the problems of lower trimming efficiency and poorer processing quality after high-current high-efficiency cutting by analyzing the main reasons influencing the trimming stability after high-current high-efficiency cutting, and the adopted measures are simple and easy to implement, thereby not only greatly improving the comprehensive cutting efficiency of multiple times of cutting, but also improving the processing precision and surface quality of the workpiece after multiple times of cutting.

2. The cleaning knife provided by the invention can reduce or eliminate the deformation of the workpiece after high-energy high-efficiency cutting, and is prepared for subsequent high-speed trimming; secondly, corrosion products in the discharge pits and the cutting seams on the cutting surface of the first cutter can be further discharged, a good environment is created for subsequent low-energy cutter repairing, as more corrosion products still remain in the cutting seams and the workpiece surface after high-energy cutting, breakdown discharge can be generated between the wire electrode and the corrosion products in the machining process of cutter cleaning, and the corrosion products absorbed in the pits on the surface can be thrown out and discharged from the cutting seams along with the interelectrode working fluid after being washed by the working fluid and pushed by the discharge explosive force during cutter cleaning; and thirdly, the surface of the large-energy cutting is flattened, the contour precision of the workpiece can be improved, the generation of discharge pits is accompanied with the generation of 'convex peaks' on the cutting surface in the process of online cutting, the second cutter adopts a clearing cutter, the 'convex peaks' left on the main cutting surface can be flattened under the action of pulse discharge, the surface of a macroscopic workpiece can be more flattened, and the improvement on the processing precision and the surface quality can be promoted to a certain extent.

Drawings

FIG. 1 is a schematic view of a multiple cut processing line of the present invention;

in the figure: 1-first cut trajectory; 2-second cutting trajectory; 3-third cut trajectory; 4-fourth cut trajectory; and 5-cutting the supporting surface for multiple times.

Detailed Description

The invention is further illustrated with reference to the following figures and examples.

The invention provides a high-current multi-time cutting method for high-speed reciprocating wire-cut electric spark wire cutting, which is implemented by adopting a four-time cutting mode, and is shown in figure 1. a is a threading point for the first high-current efficient cutting, b is an entry point, and the processing is carried out along the anticlockwise direction of a-b-c-d-e-f. And after the first cutting is finished, machining in the clockwise direction shown by a second cutting track 2, and cutting the workpiece by zero trimming amount or minimum trimming amount delta at a wire moving speed and machining energy which are more than half of those of the first cutting, wherein the trimming amount ranges from 0mm to 0.02mm, so that the discharge of residual corrosion products between electrodes is promoted, the deformation of the workpiece after high-energy high-efficiency cutting is reduced or eliminated, and the subsequent low-energy trimming can be stably and efficiently carried out. The third cutting is carried out along the anticlockwise direction shown by the third cutting track 3, the fourth cutting is carried out along the clockwise direction shown by the fourth cutting track 4, the third cutting and the fourth cutting are carried out by narrow pulse width high peak value processing so as to improve the discharge frequency in unit time, enough processing energy is ensured to erode the workpiece material, the phenomenon of blockage is avoided in the trimming process, and the processing precision and the surface quality of the workpiece are further improved. Finally, the cutting support surface 5 is machined for a plurality of times with the same energy as for the first cutting.

Experiments show that the average current of 10A is adopted for cutting in the first cutting, and the comprehensive cutting efficiency of three times of cutting (cutting one and repairing two) is about 100mm when the cutter is not cleaned²Min, the roughness of the surface of the workpiece is Ra2.0 mu m, and the surface of the workpiece has more stripes; the comprehensive efficiency of four times of cutting (cutting one, cleaning one, repairing two) after the cutter is removed can reach 170mm²Min, the roughness of the surface of the workpiece Ra1.5 mu m, and the surface of the workpiece basically has no stripes.

The present invention is not concerned with parts which are the same as or can be implemented using prior art techniques.

The limitation of the protection scope of the present invention is understood by those skilled in the art, and various modifications or changes which can be made by those skilled in the art without inventive efforts based on the technical solution of the present invention are still within the protection scope of the present invention.

Claims

1. A large-current multi-time cutting method for high-speed reciprocating wire-moving electrospark wire-electrode cutting is characterized in that: the high-speed trimming of the third cutting and the fourth cutting is carried out by adopting narrow pulse width high peak current; the zero or minimal trim delta for the second cut is in the range of 0-0.02 mm.