Posted December 4, 2018 at 4:03 am by xzbbvfvbh

High-speed grinding of cutting discs

 

High-speed grinding is a high-speed grinding in which the cutting speed of the cutting disc is Vs>45 m/s compared to the conventional grinding. As early as the 1960s, Vs has been increased to 60m/s, and in the 1970s it has increased to 80m/s. However, in the following decade, due to the limitation of the rotational speed of the cutting disc at that time and the problem of burns on the workpiece, the cutting line speed No big improvement. Until the late 1980s, with the wider application of cubic boron nitride (CBN) cutting discs, and more in-depth study of the grinding mechanism, it was found that under the condition of high wear rate, along with the cutting line speed Vs When the grinding force increases, the grinding force drops sharply in a certain interval before and after Vs=100m/s. This trend will continue with the further increase of the grinding rate, and the surface temperature of the workpiece will also fall back. That is to say, after the grinding usage area that generates thermal damage, the further increase of the grinding amount not only does not exacerbate the thermal damage but causes the thermal damage to no longer to occur, thereby developing ultra-high speed grinding and high efficiency. Deep grinding laid the theoretical foundation.

Ultra-high-speed grinding does not require strict limits, but grinding with a fiber cutting disc Chinese supplier linear velocity of Vs > 150 m/s is generally referred to as ultra-high speed grinding. In general, ultra-high speed grinding has the following advantages:

High grinding efficiency and low cutting disc loss

The higher the grinding speed, the more the number of abrasive grains participating in the cutting per unit time, the increased grinding debris, and the workpiece feed speed should be proportional to the line speed of the cutting disc of 1.13, so the ultra-high speed grinding will The grinding efficiency is greatly improved. Correspondingly, the grinding force on a single abrasive grain during ultra-high speed grinding is greatly reduced, thereby reducing the wear of the cutting disc. Many experiments have shown that when the grinding force is constant, the cutting wire speed Vs is increased from 80 m/s to 200 m/s, the grinding efficiency is increased by 2.5 times, and the life of the CBN cutting disk is also doubled.

Low grinding force and high machining accuracy

Due to the thinning of the grinding debris during ultra-high-speed grinding, the normal grinding force is significantly reduced with the increase of Vs under the condition of constant grinding efficiency (normal grinding force with Vs of 200 m/s only) It is 46% at 80 m/s, which reduces the deformation of the processing system. In addition, the excitation frequency of ultra-high speed grinding is much higher than the natural frequency of the processing system and does not cause resonance. The combined result is an increase in grinding accuracy.

The good surface quality of the workpiece

Experiments have shown that when the other conditions are constant when the line speed of the cutting disc is increased from 33 m/s to 200 m/s, the surface roughness of the grinding is reduced from Ra2.0 acid to Ra1.1 acid. Since a large amount of grinding heat will be carried away by the grinding debris during the ultra-high speed grinding process, the proportion of the incoming workpiece is small, and not only surface burn is less likely to occur, but also the depth of the surface residual stress layer becomes smaller.

Several key technologies for ultra-high speed grinding

The grinding process system is “grinding machine – workpiece – abrasive tool”. The key technology of natural ultra-high speed grinding is also inseparable from grinding machine, 125*1*22 EN12413 cutting disc、 grinding process and grinding fluid.

Research on mechanism and process of ultra-high speed grinding

At home and abroad, the research on the mechanism of ultra-high-speed grinding is not comprehensive. It is necessary to further reveal the nature of various grinding processes and grinding phenomena. At the same time, it is necessary to carry out optimization research on process parameters of different workpiece materials and grinding conditions and establish ultra-high speed accordingly. Grind the database to speed up its application. Simulating the grinding process with a computer facilitates the above research, and the virtual grinder can create a realistic grinding environment.

 

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