Application of the hottest wire cutting technology

Application of wire cutting technology in machining

with the development of science and technology, machining, especially mold processing technology, has developed rapidly. After more than 50 years of development, NC machining technology has been increasingly improved and widely used in various manufacturing fields. NC wire EDM (wire cutting for short) technology is more widely used in machining, especially in mold NC machining

1. Principle and classification of wire cutting technology

the molybdenum wire of wire cutting machine tool makes high-speed back and forth movement through the control of wire storage cylinder and upper and lower wire frames. The linearity and vertical accuracy of molybdenum wire are controlled by the guide wheels of upper and lower wire frames, and the processed parts are fixed by the base plate between the upper and lower wire frames. Connect the molybdenum wire and the processed parts to the positive and negative electrodes of the pulse power supply respectively. The processed parts are melted by the high temperature generated by the discharge, and the redundant parts of the processed parts are cut off to obtain the required mold shape

wire cutting machine tools are divided into slow wire walking machine tools and fast wire walking machine tools. Slow wire walking has high machining accuracy, but its cost is also high. Fast wire walking machine tools are widely used by most domestic manufacturers because of their simple structure, high production efficiency and low production cost. Although their machining accuracy is low, they can generally meet the needs of production. From the general development trend, the slow wire cutting machine tool is the development direction. The wire cutting machine we usually talk about refers to the fast wire walking machine tool

2. The characteristics of wire cutting technology

the development of science and technology and industrial production has promoted the development of mold Market and tool processing, especially complex mold processing. As the most commonly used and key technology in the mold processing industry, NC WEDM technology integrates electronics, machinery, computer application and control mathematics. It is mainly used to process small taper cavity molds and straight wall molds. It can not only meet the requirements of mold accuracy, but also shorten the production time, improve the production efficiency and reduce the production cost

2.1 machining parts with different shapes

with the development of science and technology, wire cutting technology has formed a complete set of intelligent digital control system. The corresponding control program is compiled for what kind of parts are processed. As long as the graphics of the processed parts are input on the machine tool, the machining process can be completed automatically. The automation of wire cutting technology makes the production process more flexible and convenient. Parts of any shape can be processed automatically, especially parts with complex and difficult shapes (such as convex concave dies in stamping dies and inserts in injection molds, sharp corners in complex die cavities and through holes with small taper, etc.), wire cutting can give full play to its technical advantages

2.2 processing high hardness materials

the temperature generated by the positive and negative electrode discharge of wire cutting machine tools can be as high as 10000 degrees Celsius, which can melt all kinds of metal materials. Therefore, in the processing process, it is not limited by the hardness of parts, and can process any high hardness materials, such as cemented carbide, polycrystalline diamond and quenched tool steel

2.3 improve the accuracy of parts

wire cutting machine uses electricity and heat to process parts, which can flexibly adjust various parameters that affect the accuracy of parts, which is conducive to improving the accuracy of parts, so as to realize the automation of the processing process

disadvantages of wire cutting machine tool: it is only suitable for the processing of parts with small quantity and complex shape or R & D products, while the cost is too high for large quantities of parts with relatively simple shape; And non-conductive materials cannot be processed

3. The application of machining center line cutting technology

3.1 fine expand and strengthen the import and export trade with Southeast Asia to set the transition circle radius

in the process of machining, wire cutting technology is used to accurately set the transition circle radius, which also avoids many human errors in practical application. The transition circle radius will be affected by the shape of the processed workpiece and the machining accuracy of the parts. In general, the greater the wall thickness of machined parts, the larger the radius of the transition circle. At the same time, in the process of machining, the transition circle radius should be properly adjusted in combination with the gap size when the mold is matched, and in order to meet the cutting accuracy of machined parts, the accuracy control of the machine tool should be strengthened to accurately determine the transition circle radius

3.2 machining of convex and concave corners

the application of wire cutting technology in machining sets the motion trajectory of fine wire according to the motion of electrode wire. In practical application, there is error in the diameter of electrode wire, so there is a certain gap between fine wire and the machined surface of workpiece, which makes machining error. In order to control the machining error of mechanical parts to the greatest extent, when calculating the motion trajectory of electrode wire, Taking into account the discharge gap and electrode wire diameter error, when using wire cutting technology for machining, the larger the electrode wire radius, the larger the discharge gap and calculation error, and the concave corner can only become a fillet after mechanical cutting. Because of the service trip, the staff should analyze the specific problems when machining convex and concave mechanical parts. In practical application, when machining concave parts, the electrode wire motion track should subtract the length of discharge gap; When machining convex parts, the movement track of electrode wire should be added with the length of discharge gap, so as to ensure the machining accuracy of mechanical parts

3.3 fixed mold processing

if the radius of the template hole is between 0.06 and 0.1mm, the cutting line with a diameter less than 0.1mm should be used as much as possible. The precision of fine wire cutting technology is higher than that of coarse wire cutting technology. During machining, the processing speed should be reasonably controlled to avoid frequent wire breakage. However, the use of fine wires in the machining of the whole hole will cause material waste on the one hand, and the machining efficiency is low on the other hand, Therefore, it should be carefully compared and analyzed in combination with the actual situation of the template. For example, when cutting all the shaped holes with thick wires, after meeting the machining requirements, the corner radius should be appropriately adjusted, and then the thin wire should be used to cut the shaped holes, so that all the shaped holes can meet the machining requirements. In addition, it should be noted that the thick wires and thin wires should be replaced during machining, and the machining workpiece center should be re determined, Ensure that the distance between the original center of the workpiece and the positioning center is controlled within 0.15mm

3.4 dynamic die machining

dynamic die machining is a very important process in die machining. Design shape, material hardness, dimensional accuracy and other factors have a direct impact on the die blanking quality, and affect the service life and stamping accuracy of die parts. The machining process of the moving die is divided into the following steps: first, according to the machining requirements, punch the workpiece at the appropriate position with a punch or an electric spark, process the workpiece well, and then insert it into the control die. The tangent segment between the center of the punching wire and the contour line of the moving die should be kept at 7-9mm; Second, the width of punch contour and blank edge should be less than 1/4 of blank thickness; Third, when selecting the reserved pause point for subsequent cutting, the distance between the workpiece center point and the pause point should be reduced as much as possible, and the appropriate width should be set according to the workpiece size. Generally, the width should be greater than 3mm and less than 4mm; Fourth, when the workpiece is twisted and deformed, the residual deformation of one-time rough cutting shall be controlled within 0.12-0.16mm, and the fine cutting shall be carried out repeatedly for several times to minimize the cutting allowance,

the distortion and deformation of the workpiece shall be controlled to the greatest extent; Fifthly, after the machined workpiece completes four contour cuts, the whole machining is almost completed. The staff uses alcohol to clean the blank end face, uses compressed air to blow dry the blank end face, and then uses adhesive or 502 glue to paste a metal sheet on the blank. The thickness of the sheet is about 0.25mm. In order to prevent the glue from affecting the machining, it is strictly forbidden to drop glue in the reserved connection area of the workpiece, Finally, the workpiece is cut according to the machining offset

4. Conclusion

with the rapid development of modern industry, the machining industry will develop towards the direction of short production cycle, low cost and high precision. Wire cutting technology occupies an important position in the machining industry because of its advantages in improving product quality and work efficiency, expanding production scope and reducing production costs. Therefore, the research and exploration of wire cutting technology is of great and far-reaching significance