TAGUTI

Current Status and Development of Electrical Discharge Machining TechnologyWire cut EDM

Since 1956, the former Soviet Union produced the first EDM wire cutting machine. It has been a long history more than 40 years. During this period, both domestic and foreign EDM machines have undergone tremendous changes. For example, WEDM industry changed from the initial “mould-electric wire cut machines, to photoelectric wire cut machines, and to CNC wire cut machines and a series of processing Technology, process improvement. Wire cut EDM has become the most widely used special processing method, which increasingly arouses people’s attention and concern.

TAGUTI INDUSTRIAL LIMITED established in 1997 to cater to the market demand as the very earlier generation. TAGUTI initiated the cold draw technology of molybdenum wire, which lasts 20 years. In early time, we started to produce air filter for the Chinese domestic market. And now we mainly generate TAGUTI EDM filters for both Chinese and overseas markets. Such edm consumable companies like TAGUTI have a great impact on the Chinese EDM wire cut development.

Speaking of wire cut EDM, people first thought is high-speed EDM wire cutting process. As China’s original technology model,High-speed wire EDM machine has become China’s largest CNC machine tool in the production and one of the most widely used models. It is estimated that there are tens of thousands of high-speed wire EDM machines that plays an important role in the mold manufacturing and spare parts processing.

In recent years, the development of high-speed wire EDM machine is unsatisfactory in some ways, but it still makes gratifying achievements. First of all, in the number of selling machine tools, it has made a great breakthrough and achieved a broad foundation. There are indeed some problems and issues, but overall development is moving forward. The annual output of EDM Machine production increased from 2-3 thousand units to more than 10,000 units. Besides the cost performance has also been greatly improved.

Specifically, the wire cut EDM machine development mainly reflects in the following areas:

(1) large taper cutting technology is developing rapidly and has been gradually improved and matured. In the taper processing, the electrode wire follows the inclination to ensure that the guide wheel groove is always in the same plane, which solves the problem that the electrode wire easily jumps out when the taper cutting is done. The improvement of the controling technology adopts various compensations, which effectively improves the precision of taper processing. The enhancement of working fluid spray method improves the processing state of large taper cutting. Along with the development of large taper cutting technology, variable taper, the different top and bottom shapes cutting processing have also made great progress.

(2) The technology of large thickness cutting advances continuously and other processing technology improves at the same time. Large thickness cutting is a special know-how for high-speed wire cutting EDM process. It has obvious advantages compared with low speed wire cut EDM machine. In recent years, the promotion and improvement of large thickness cutting technology have expanded the application scope of high speed wire cut EDM machines and stimulated its development.

(3) The exploration of cutting process technology for several times has achieved some advancement. Although many times cutting technology is not yet mature now, It has a good start for wire cut edm due to useful explorations, testings and some applications by many parties.

(4) The technic index and technology level of wire cut edm machines and cnc machines have been

advanced. Various characteristics of the wire movement system, wire processing agencies make the “stripes” improved step by step. There are varieties of frequency control mode of exploration, such as the use of neural networks, fuzzy control, adaptive control. In particular the successful introduction of low-speed wire cutting processing pulse power control and frequency feed mode, achieve a highly efficient, stable and low-loss processing. Pulse power of continuous improvement changes the cutting speed from the original 60 ~ 80 mm2 / min to increased one of 100 mm2 / min. Accordingly, our TAGUTI factory also produces molybdenum wire with high quality and good cost performance which saves most in the wire cut edm.

(5) The machine structure has made new progress and is no longer the single sound structure. Both appearance, overall image and performance have been greatly improved.

In addition, there are arge gantry type of wire cutting machine, HS-WEDM, LS-WEDM, and adjustable wire speed type of wire edm, and spinning wire cut edm machine. The machine structure and wire walking way have innovated and contributed to the development of WEDM machining technology.

(6) The controlling system continues to be updated and perfectly mature. Most of the new controlling systems adopt the PC machines, and continue to upgrade with the main chip upgrading. The control system of wire cut edm continues to increase more functions. It has become a trend that wire edm machine is compatible with ISO code.

Overall, high speed wire cutting machine process owns better cost and price performance for most Chinese domestic needs because the wire cut machine has a simple structure, easy operation, good maintainability, the low-cost of use, small floor space and low price. In the middle and low level of molds and parts processing, the edm wire machine shows great applicability and more advantages, especially in large thickness, variable thickness processing.

However, compared with low-speed wire cutting EDM technology, the development of high-speed electrical discharge machine cutting technology is slow, and processing quality is poorer. Therefore many domestic research institutes and manufacturers as early as 10 years ago have studied the production of low-speed wire EDM. After years of efforts, the recent two years achieve a breakthrough in some ways. In 2000, the annual sales volume is just a few dozen (about one-ninth of the national market), that is to a largest machine production manufacturer of low-speed wire cut edm machine in domestic production. But in 2002, the annual sales have reached more than 100 wire cut edm machines (about the one-fifth of the Chinese market). These wire edm

machining manufacturers make all machines a new high level through joint ventures and reach the international level in the early 1990s. The cutting speed is up to more than 200 mm2 / min and the processing accuracy is up to 5 microns and the roughness Ra to a fraction of a micron. The price is only 0.5 million RMB (about one-half of similar imported machine tools). All of these win a good start and a broad prospect for wire edm machine in China. The domestic annual market volume of low-speed wire cut edm machines has increased from 300 in 2000 to about 700 in 2002. With the rapid development and technology improvement of mould industry, the processing for precision parts are raised. The price of low-speed wire cut edm machine and edm consumables decline quickly. So many companies like our TAGUTI INDUSTRIAL LIMITED start to supply more edm spare parts for the edm market. In recent years, Chinese wire cut edm machines lie in a great and special important position in the internation market in view of the progressive understanding and comprehensive supply of EDM consumables.