1）Multiple cuts possible
The significant difference between the middle wire and the fast wire is that it can realize multiple cuttings, improve the surface quality of the machined workpiece, and meet the needs of machining the workpiece, thus expanding the scope of adaptation. For example, in the middle wire machine, after three times of cutting, the surface roughness reaches Ra≤1.2μm.
2）Low wire loss and energy saving
In order to achieve multiple cutting and to ensure processing efficiency, it is necessary to increase the cutting speed during roughing, which requires close cooperation of the pulse power source. To this end, according to the development of power electronics technology, the pulse power supply of the medium wire cutting machine tool has been improved, and the current limiting resistor has been eliminated, which not only improves the performance of the pulse power supply, but also saves energy.
At present, the maximum cutting speed of the medium-travel pulse power source is close to 200 mm 2 /min, and the average speed of multiple cutting (for example, three times) can reach about 60-80 mm 2 /min; and, the effect of extremely low electrode wire loss is obtained. Therefore, some are called intelligent high-frequency pulse power supplies.
3）Intelligent control system
In the middle of the wire cutting, the industrial PC is used to form an integrated programming control system. Combined with the process database, the system can provide the best processing conditions to achieve high-speed machining, quality assurance and simplified operation.
For example, after inputting processing conditions (material, thickness, etc.), process parameters (surface roughness, etc.), the system can give appropriate electrical specifications (pulse width, pulse interval, no-load voltage, machining voltage, machining current). Etc.), as well as the servo feed rate, wire speed, etc., are processed separately and react appropriately during processing.
Therefore, the control system needs the close cooperation of the pulse power supply and the electrical system of the machine tool. It is also called "intelligent multi-speed wire cutting machine".
4）Can realize frequency conversion speed regulation
In order to meet the different requirements of each cutting, the wire speed requirement of the electrode wire can be adjusted. The middle wire cutting machine adopts AC frequency conversion speed regulation, and replaces the relay control circuit with electronic logic circuit. At the same time, it is convenient to interface with the control system. Control of the speed of the wire. After adopting the frequency conversion speed regulation, the commutation impact of the wire motor is also slowed down, which is beneficial to keep the electrode wire stable.
5）High precision machine tool
In order to ensure the effect of multiple cutting, the machine tool must have high repeat positioning accuracy, which has certain requirements for the bed and guide rails. The accuracy and durability of the machine must be maintained by using the right structure, the right materials, the use of linear guides, and the feed system with gap-free gear pairs or straight-forward clearance of the motor. In terms of the stability of the electrode wire, various measures have also been taken.In addition, the middle of the wire has also developed a new working fluid, a new filtration system to meet processing and environmental requirements.
