High speed wire EDM machine with Chinese characteristics

An objective understanding is necessary for reciprocating wire cutting

Both "HS-WEDM" and "LS-WEDM" belong to the "wire cutting machine". LS-WEDM brings operating costs due to the unidirectional use of the electrode wire. Frequent reversal of the "reciprocating wire walking" is a method for the repeated use, high-speed operation, and cost reduction of the electrode wire. It is "reciprocating commutation" that allows high-speed wire feeding, and it is "reciprocating commutation" that achieves low operating costs.

The "reciprocating wire cutting" has all the advantages of wire cutting: simple structure, low operating cost, high cutting efficiency, convenient operation, and strong thickness cutting ability.

The "reciprocating wire cutting" also brings about the major drawbacks of wire cutting: the reversal of the wire will cause displacement and there will be reversal stripes. And due to the combined effects of factors such as the tension of the wire, the tenacity coefficient of the wire, the viscosity of the liquid, the inertia of the guide wheel, the resistance of the guide wheel, the thickness and cutting characteristics of the cutting material, and the processing electrical parameters, this combined effect is variable and unstable. (See reversing displacement in the figure)

The "reciprocating wire cutting" also brings another disadvantage of wire cutting: the decrease in insulation capacity at the discharge point can lead to the release of multiple pulse energy concentrated at one point of the wire. After burning and carbonizing at one point of the wire, it can quickly spread and infect, leading to a decrease in the current carrying capacity and tensile strength of the entire wire, leading to wire breakage. (See burn carbonization in the figure 4)

Wire cutting machine can be said to have enjoyed the development achievements of the electronic industry, making high energy consumption, large volume, and high failure rate a thing of the past. It is not difficult for current electrical control systems to achieve digitization, high reliability, low failure, and even lifelong maintenance free.

The modern mechanical industry has vigorously promoted the development of wire cutting, and the application of drive motors, ball screws, and linear guides has eliminated precision issues such as coordinate displacement, repeated positioning, and transmission backlash in the machine tool industry. The mechanical system accuracy of 0.02mm, which was pursued several decades ago, has now been truly unquestionably improved to μ Level.

The existence of "reverse displacement and reverse stripes" in "reciprocating wire cutting" fails to demonstrate the high accuracy of the "mechanical system". The accuracy loss caused by "commutation fringes" (or fundamentally "commutation displacement") is much greater than that of "mechanical system accuracy". μ The level of "mechanical system accuracy" is often tens of μ Compared to the 'directional stripes', it's simply not worth considering. Is there a true difference between fast wire and slow wire between "directional displacement and directional stripes". The use of "intermediate threading and multiple cutting" is only a measure to conceal and eliminate "directional stripes", and the ever-changing instability still exists. It is impossible to maintain the same directional stripes and smoothness (whether good or bad) for a long time. The "burn carbonization" of discharge machining is a random phenomenon that cannot occur without it. The "burn carbonization" of a point on the molybdenum wire loses the prerequisite for high current "cutting". Moreover, the "back and forth wire" and "burn carbonization" can have a strong spread of infection. If you try to "reverse" without "stripes"; Discharge without arcing is like walking without footprints, and it is not objective.

The current manufacturing industry of wire cutting machine tools regards the fundamental shortcomings brought about by "reciprocating commutation" as the "consensus" of the industry (including users), and the established "accuracy, smoothness, and speed" indicators all exclude the existence and impact of "reciprocating commutation". The term 'accuracy' does not include the impact of 'directional fringes' on dimensions (the accuracy shown in the standard is actually static measurement accuracy); The "smoothness" does not include the serrations caused by the "directional stripes" (the convexity and concavity of the serrations are much greater than the convexity and concavity of the pits); Cutting "is achieved by high current, (even if only a few points of" burn carbonization "lose the reliability of high current operation). But these 'consensus' are recognized by new users and require time and practical experience. This is why customers will no longer raise the issue of "reversing stripes and cutting efficiency" in a few years. This is also the reason why over 800000 "reciprocating wire cutting" machines nationwide are operating normally.

It is China's and historical reasons" that make the "reciprocating reversing" wire cutting machine rely on "consensus" to explain "accuracy, smoothness, and speed". Those who already understand do not need to explain, and those who have not yet understood cannot listen to your explanation., It is necessary to use "reciprocating and reversing wire cutting", but the characteristic process indicators exclude the impact of "reciprocating and reversing", which is indeed * compared to the traditional machine tool industry's "rigorous and reliable indicators". It is not a single enterprise, individual, or scope that can solve the problems of "industry", "history", and "*". We still need to work together with our users to follow that 'consensus'. We also need to acknowledge the drawbacks brought about by "reciprocating commutation", and we cannot change the fundamental shortcomings that cannot be solved by the entire industry.

Machines rely on "consensus" to coordinate the judgment of indicators between buyers and sellers, and "reciprocating wire cutting" is * in the entire machine tool industry. This * is due to "historical reasons". The concept of "reciprocating wire cutting" was born and commercialized in the 1970s, which was an era of "material scarcity and commodity scarcity". With the ticket certificate and indicators, wait in line for shipment after the full payment is made. The user unconditionally assumes all responsibility for repairing the machine tool after receiving it. What is truly questionable is not the machine tool but one's own abilities. The seller also does not need to refine and standardize various "technical indicators", and can achieve the machine tool's "stability, low failure rate, responsible maintenance, and timely and effective personnel training", which is already commendable. It is precisely this overly tilted seller's market that has abandoned the tradition of the machine tool industry of being rigorous, reliable, and unquestionable, with room for digital indicators. It is precisely this overly tilted seller's market that has led to rapid expansion of production capacity, coupled with the rapidly changing market environment, that the industry has evolved into a "buyer's market" at an unexpected speed. The exchange of positions between the buyer and the seller has resulted in the loss of the opportunity to "carefully verify and rigorously express" the "technical indicators" maintained by "consensus". In fact, for users, understanding and acknowledging "consensus" is the beginning of making good use of "reciprocating wire cutting"; You won't change the inherent rules just because you "compete". Undoubtedly, 'arrears' can psychologically guide users to resist' consensus' and misplace their focus, causing them to try their best to make good use of 'arrears', while delaying the use of' good use 'machine tools. This is a major challenge left by the' consensus formed due to historical reasons' for the 'reciprocating wire cutting' industry.