Company name: zhengzhou hengfeng abrasive tools co., LTD
Contact person: manager Chen
E-mail: 1099564586 @qq.com
Address: no.166, qinling road, zhengzhou, henan, China
Grinding is a method of machining workpiece with grinding wheel as cutting tool on the grinder. The characteristics of this method are:
(1) grinding can process materials with high hardness, such as hardened steel and hard alloy, due to its high hardness and heat resistance.
(2) the characteristics of the grinding wheel and the grinding machine determine that the grinding process system can make uniform micro cutting, generally ap=0.001 ~ 0.005mm; High grinding speed, generally up to v=30 ~ 50m/s; Good rigidity of grinding machine; With hydraulic transmission, grinding can achieve high machining accuracy (it6 ~ it5) and small surface roughness (ra=0.8 ~ 0.2 m) economically. Grinding is one of the main methods for finishing parts.
(3) the grinding zone temperature is very high due to severe friction. This can cause stress and deformation of the workpiece, or even surface burns. Therefore, a large amount of coolant must be injected to reduce the grinding temperature. Coolant can also play a role in chip removal and lubrication.
(4) great radial force during grinding. This will cause the machine tool - grinding wheel - workpiece system elastic concessions, so that the actual cutting depth is less than the nominal cutting depth. Therefore, when the grinding is about to be completed, the knife should not be polished to eliminate errors.
(5) after the abrasive grains are blunt, the grinding force also increases, causing the abrasive grains to break or fall off, re-exposing the sharp edge, which is called "self-sharpening". Self-sharpening enables grinding to be carried out normally within a certain period of time, but after a certain working time, manual dressing should be carried out to avoid vibration, noise and surface quality damage caused by increased grinding force.
A grinding wheel is a cutting tool for grinding. It is a porous object made of many small hard abrasive particles and binders. The abrasive grain bears the cutting work directly, must be sharp and has the high hardness, the heat resistance and certain toughness. Commonly used abrasives are alumina (also known as corundum) and silicon carbide. Alumina abrasive with high hardness and toughness is suitable for grinding steel. Silicon carbide abrasive has higher hardness, sharper, good thermal conductivity, but more brittle, suitable for grinding cast iron and hard alloy.
The same abrasive grinding wheel, due to its different thickness, workpiece processing surface roughness and processing efficiency is not the same, abrasive coarse for coarse grinding, fine grinding particle size for fine grinding, the coarser the abrasive, the smaller the particle size.
The binder ACTS as a bond to the abrasive. Ceramic binder is commonly used, followed by resin binder. Different binder materials affect the corrosion resistance, strength, heat resistance and toughness of the grinding wheel.
The more firmly the abrasive particles bond, the more difficult it is to fall off the grinding wheel, it is called the hardness of the grinding wheel, that is, the hardness of the grinding wheel refers to the degree of difficulty of the grinding particles on the surface of the grinding wheel falling off under the action of external forces. Easy to fall off is called soft, conversely called hard. The hardness of grinding wheel and abrasive are two different concepts. The surface of the workpiece is soft, abrasive edge (edges and corners) is not easy to wear, so that the abrasive can be used for a longer time, that is to say, optional bonding solid grinding wheel (higher hardness grinding wheel). On the contrary, the grinding wheel with low hardness is suitable for grinding the workpiece with high hardness.
The grinding wheel works under high speed condition. In order to ensure safety, inspection should be carried out before installation. There should be no cracks or other defects. In order to make the grinding wheel work smoothly, the balancing test should be carried out before use.
After working for a certain period of time, the surface gap of the grinding wheel will be blocked by grinding debris, the sharp Angle of the abrasive will be blunt, and the original geometry will be distorted. Therefore, trimming is necessary to restore cutting power and correct geometry. The grinding wheel needs to be trimmed with a diamond pen.
Structure and grinding movement of surface grinder
There are many types of grinding machines, including surface grinding machine, external grinding machine, internal grinding machine, universal external grinding machine (also can grind internal hole), gear grinding machine, thread grinding machine, guide grinding machine, centerless grinding machine (grinding external circle) and tool grinding machine (grinding tool).