Grinding machine grinding mechanism

Belt grinder grinding is a special form of abrasive belt grinding tool. It is tensioned by means of a tensioning mechanism, and the driving wheel is made to move at a high speed. Under a certain pressure, the belt is brought into contact with the surface of the workpiece. Realize the entire process of grinding.

Broadly speaking, belt grinding and grinding wheel grinding are the same as the "micro-blade cutting tool" for high-speed motion - the cumulative effect of micro-cutting of abrasive grains. Therefore, the grinding mechanism is roughly the same. However, due to the different characteristics of the belt itself and the way it is used, the grinding of the belt is not only in the grinding mechanism but also in the comprehensive grinding performance, which is different from that of the grinding wheel. This is mainly manifested in:

1) Grinding wheel grinding is rigid contact grinding, while belt grinding is elastic contact grinding, and even in the case of using inelastic steel contact wheels, because of the composition of the substrate, adhesive tape The knuckles have a certain degree of elasticity, let alone using elastic rubber as the contact wheel in most cases.

Because of this, in addition to the same grinding, ploughing and cutting functions of the grinding wheel, the grinding of the abrasive belt also has the effect of the abrasive particles squeezing the surface of the workpiece and causes plastic deformation, chill layer change and surface tearing. , and the combined effect of thermoplastic flow caused by frictional contact point temperature rise. Therefore, from this point of view, abrasive belt grinding has multiple functions of grinding, grinding and polishing at the same time. This is the reason why the quality of the sanded surface is good.

On the other hand, due to the elastic grinding characteristics of the belt, the length of contact of the belt with the workpiece in the grinding area is larger than that of the grinding wheel. At the same time, the number of abrasive grains participating in grinding is large and the load of a single abrasive grain is large. Small, uniform, and small breakage of abrasive particles. The wear ratio of the entire belt (the ratio of grinding material removal to abrasive belt abrasive consumption is called the grinding ratio, and the reciprocal of the grinding ratio is called the wear ratio) is much smaller than that of the grinding wheel.

2) The distribution of the abrasive grains of the grinding wheel on the grinding surface is disorganized and very irregular. In the actual grinding, the abrasive grains are cut with a large negative rake angle, a small relief angle and even a negative relief angle. , cutting conditions are very harsh. The abrasive belts are different. Abrasives on the abrasive belts are specially manufactured. The geometry of the abrasive particles is often the Yangtze River Delta body. It is often made using a series of advanced techniques such as electrostatic sand-blasting. The size and distribution of the abrasive particles are uniform and the contours are good. , And the sharp-edged pattern is planted on the surface of the abrasive tape substrate, and more parts of the adhesive layer are exposed. Therefore, the abrasive grain of the abrasive belt is sharper than the abrasive grain of the grinding wheel, the cutting conditions are better, the material deformation during grinding is small, the removal rate is high, the grinding force and the consequent grinding heat are small, and the grinding temperature is low.

3) Abrasives between grinding wheels are full of binders and the space for the chips is small. The space between the abrasive grains of the abrasive belts is generally at least 10 times larger than that of the grinding wheels, and the abrasive grains are of equal height. Therefore, the effective cutting area of ​​the abrasive grains is large, the cutting ability is stronger than that of the grinding wheels, and the grinding debris can be taken away at any time. , Very little residue remains on the surface of the belt causing blockages, which does not increase frictional heating, and the temperature in the grinding zone is low.

4) The circumference of the abrasive belt can be far beyond the circumference of the grinding wheel from the design point of view. This allows the belt to have both a good cooling area and a suspended part of the belt (ie, not The parts contacted by the contact wheel, tensioner, platen, etc.> are oscillated during operation and naturally shake off the abrasive particles stuck on the abrasive belt, further reducing the phenomenon that the abrasive particles are filled, thereby reducing friction and heating. One reason for the low temperature of the belt grinding.

It can be seen that the processing mechanism of abrasive belt grinding is a more complex form that is similar to grinding wheel grinding and grinding wheel grinding. This is the theoretical basis and fundamental starting point for analyzing and understanding the grinding mechanism of belts.

Wuxi Taiyuan Machine Manufacturing Co., Ltd.

Li Xiaoqing13771428027