Analysis of the requirements of high speed cutting of the machine tool

In the contemporary mold production, the requirements for the elegance and function of the plastic parts are getting higher and higher, and the internal layout plan and shape of the plastic parts are becoming increasingly chaotic. The proportion of the liberation surface continues to grow, and the corresponding mold layout plan is getting more and more. Confusion. All of these have placed higher demands on mold processing skills, not only to ensure high manufacturing precision, appearance quality, but also to require elegant processing. With the continuous deepening of high-speed machining skills, especially in the continuous growth of machining tools, cnc systems, CNC tool systems, CAD/CAM software and other related skills, high-speed machining skills have been increasingly applied to mold types. Processing and manufacturing of cavities.

Cnc high-speed cutting plus labor is one of the most pressing advances in the mold industry: manufacturing skills are advanced manufacturing skills that combine efficiency, quality and low cost. Compared with the boring cutting process, the cutting rate and feed rate have been greatly improved, and the cutting mechanism is not the same.

High-speed cutting makes the cutting process produce quality Mercedes-Benz, the metal removal rate per unit power is improved by 30%~40%, the cutting force is reduced by 30%, the cutting life of the tool is improved by 70%, and the cutting heat left on the workpiece is large. The amplitude is low and the low-order cutting vibration almost disappears. With the advancement of the cutting rate, the removal rate of the blank material per unit time has increased, the cutting time has been reduced, and the processing effect has been improved, thereby shrinking the manufacturing cycle of the product and improving the market competitiveness of the product.

At the same time, the small amount of fast advancement of high-speed machining reduces the cutting force, and the high-speed displacement of the chips reduces the cutting force and thermal stress deformation of the workpiece, and improves the rigidity difference and the probabilities of the cutting processing of thin-walled parts. Due to the low cutting force, the advancement of the rotational speed makes the cutting system's labor frequency far from the low-order natural frequency of the machine tool, and the workpiece roughness is the most agile to the low-order frequency, thereby lowering the appearance roughness. In the processing of high-hardened steel parts (HRC45~HRC65) of the mold, high-speed cutting can replace the steps of electric machining and grinding and polishing, thereby prohibiting the manufacture of electrodes and time-consuming electrical processing, and greatly reducing the fitter's work. Grinding and polishing amount. High-speed milling can also be successfully completed for some thin-walled mold parts that are increasingly necessary in the market, and in the center of high-speed milling CNC machining, the mold can be multi-step machining in one clamping.

High-speed machining skills have a huge impact on the mold processing process, changing the tedious process of “annealing→milling→heat treatment→grinding” or “electric pulse processing→manual grinding, polishing”, etc. High-speed machining replaces all the original processes. High-speed machining skills can be applied to direct machining of hardened mold cavities (especially semi-finishing and finishing), and have been widely used in EDM electrode processing and rapid prototyping. Mass production practice proves that the application of high-speed cutting skills can reduce the manual grinding time of about 80% of the subsequent processing of the mold, saving about 30% of the cost of adding people, the machining accuracy of the mold appearance can reach 1m, and the cutting effect of the tool can be doubled.

Second, high-speed milling machine tools

High-speed cutting skills are one of the important growth directions of cutting skills. It has taken a higher step with the development of fundamental skills such as CNC skills, microelectronics skills, new materials and new layouts. Due to the speciality of mold processing and the characteristics of high-speed machining skills, the coherent skills and process systems (machining machine tools, cnc systems, end mill cutters, etc.) for high-speed machining of molds have higher requirements than boring mold processing.

1. High stability machine support parts

Supporting parts such as the bed of a high-speed cutting machine should have good dynamic and static stiffness, thermal stiffness and optimum damping characteristics. Most of the machine tools use high-quality, high-rigidity and high-tensile gray cast iron as support component materials, and some machine tool companies also grow high-damper polymer concrete in the base to increase their vibration resistance and thermal stability. This not only guarantees the accuracy of the machine tool, but also prevents the tool from vibrating during cutting. The use of a closed bed plan, a group cast bed, a symmetrical bed layout and dense ribs are also a tense way to improve the stability of the machine. Some of the machine tool companies' R&D parts are in the planning process, and they also adopt modal analysis and finite element layout planning to optimize the layout and make the machine support components more stable and reliable.