Daily maintenance1. The working surface of spark machine should be kept clean. If not, it is easy to cause rust.2. Confirm whether the oil pump pressure is normal.3. Keep the appearance of the equipment clean and tidy.Weekly maintenance1 hand pressure oiler, 3 times each time.2. Check the oil quantity of manual oiler.Monthly maintenance1. Grease the guide rails of spark machine.2 check the disk accuracy. (check the flatness with dial indicator)Quarterly maintenance1 check whether the spark machine level is normal. (check whether the level of worktable is correct with level meter)2. Check the accuracy of three axes of spark machine. (check whether the stroke is correct with pitch gauge)Annual maintenance1 check and clean the spark machine oil tank.2 check and replace z-axis lubricating oil of spark machine. (please contact Qun Ji service department for details)3 check and clean the electric cabinet. (please contact Qun Ji service department for details)

In 1943, the Soviet scholar Lazarenko and his wife researched and invented EDM, and then developed rapidly with the improvement of pulse power supply and control system. The first pulse power supply used was a simple resistor capacitor circuit. In the early 1950s, it was improved to resistance inductance capacitance circuit. At the same time, the so-called long pulse power supply such as pulse generator is used to improve the etching efficiency and reduce the relative loss of tool electrode.Subsequently, high-power electron tube, thyratron and other high-frequency pulse power supply appeared, which improved the productivity under the condition of the same surface roughness. In the mid-1960s, transistor and silicon controlled pulse power supply appeared, which improved the energy efficiency and reduced the tool electrode loss, and expanded the adjustable range of rough and finish machining.In the 1970s, high and low voltage composite pulse, multi loop pulse, constant amplitude pulse and adjustable waveform pulse power supply appeared, and new progress was made in machining surface roughness, machining accuracy and reducing tool electrode loss. In the aspect of control system, from simply keeping the discharge gap and controlling the advance and retreat of tool electrode at the beginning, to using microcomputer to control various factors such as electrical parameters and non electrical parameters in time.

When EDM is carried out, the tool electrode and workpiece are connected with the two poles of pulse power supply respectively, and immersed in the working fluid or the working fluid is filled with discharge gap. The electrode is fed to the workpiece by the gap automatic control system. When the gap between the two electrodes reaches a certain distance, the pulse voltage applied on the two electrodes breaks down the working fluid and generates spark discharge.In the micro channel of discharge, a large amount of heat energy is gathered instantaneously, the temperature can be as high as 10000 ℃ and the pressure also changes dramatically. Therefore, the local trace metal materials on the working surface of this point are melted and gasified immediately, and splashed into the working liquid explosive, and condensed rapidly, forming solid metal particles, which are taken away by the working fluid. At this time, a small dent mark is left on the surface of the workpiece, and the discharge stops for a short time, and the working fluid between the two electrodes is restored to insulation state.Next, the next pulse voltage breaks down at another point close to each other, producing spark discharge, and repeat the above process. In this way, although the metal quantity of each pulse discharge is very small, because of thousands of pulse discharge per second, more metals can be removed, with a certain productivity.Under the condition of keeping the constant discharge gap between tool electrode and workpiece, the tool electrode is fed to the workpiece continuously while the metal of the workpiece is eroded, and the shape corresponding to the tool electrode shape is processed. Therefore, as long as the shape of tool electrode and the relative movement between tool electrode and workpiece are changed, various complex profiles can be processed. Tool electrodes are commonly used with good conductivity, high melting point and easy to process corrosion resistant materials, such as copper, graphite, copper tungsten alloy and molybdenum. In the process of machining, tool electrode also has loss, but it is less than the metal removal amount of workpiece, even close to no loss.Working fluid as discharge medium also plays a role of cooling and chip removal in the process of processing. The commonly used working fluid is a medium with low viscosity, high flash point and stable performance, such as kerosene, deionized water and emulsion. The characteristics of the EDM are as follows: the two electrodes of spark discharge have a high voltage before discharge. When the two electrodes are close, the dielectric is broken down, and then spark discharge occurs. With the breakdown process, the resistance between the two electrodes decreases sharply, and the voltage between the two poles decreases sharply. The spark channel must be extinguished in a short time (usually 10-7-10-3s) before the "cold pole" characteristics of spark discharge (i.e. the heat energy transferred by the channel energy cannot be transmitted to the depth of the electrode) can be maintained, so that the channel energy can be applied to a minimum range. The effect of channel energy can cause the electrode to be corroded locally. The method of size processing of materials by using the corrosion phenomenon of spark discharge is called EDM. EDM is a spark discharge in liquid medium in a lower voltage range. EDM According to the form of tool electrode and the relative movement between the workpiece and the tool, EDM can be divided into five types: EDM machining with tool electrode and simple feed motion for relative workpiece; using the metal wire moving axially as tool electrode, the workpiece moves according to the required shape and size to cut conductive materials by EDM wire cutting; The EDM grinding of small hole grinding or forming grinding is carried out by using metal wire or formed conductive grinding tool electrode. It is used for machining the screw ring gauge, thread plug gauge [1], gear, etc.; the small hole processing, surface alloying and surface strengthening of the surface. EDM can process materials and complex shape workpieces which are difficult to be cut by common cutting methods; there is no cutting force during machining; no defects such as burr and groove are produced; tool electrode material need not be harder than the workpiece material; direct use of electrical energy processing is convenient for automation; after machining, the surface of the workpiece is produced with metamorphic layer, which must be further removed in some applications; purification and purification of working fluid The treatment of smoke pollution produced in the process is more difficult.