Grinding wheel dressing is divided into two steps: Truing and dressing.

Why need Dressing grinding wheel?

Dressing is to establish the coaxiality and geometric shape of the grinding wheel. After dressing, it cannot be ground normally and must be truing to make the tip of the abrasive grains finely broken to form cutting edge . Truing methods include: turning, rolling Truing, diamond roller, etc.

Why need truing grinding wheel?

Truing is to improve the grinding performance of the grinding wheel by removing the bond between the abrasive grains of the grinding wheel, so that the abrasive grains protrude from the surface of the bond, forming the necessary grinding edge and chip space.

There are many Truing methods, currently there are mainly two types: free abrasive Truingand consolidated dresser sharpening:

The dressing process of the grinding wheel is to first shape the abrasive grains that are worn out and passivate, and repair a new grinding micro-blade; crumb space.

The diamond roller dressing method can be used as a Truing and Truingtool at the same time. By adjusting the process parameters of the grinding wheel dressing, the Truing and Truingof the CBN grinding wheel can be completed in one clamping.

Ordinary ceramic bond is soft, which can be removed by participating in grinding. In addition, the turning and Truing method also has a partial Truingeffect. Therefore, ordinary grinding wheels generally do not have a Truing.

The bonding agent of CBN grinding wheel is relatively hard. When dressing with diamond roller, the dressing parameters can be adjusted to realize the Truing and Truingof the grinding wheel.

The Truinglink can be omitted during grinding wheel dressing, which simplifies the dressing process and meets specific processing requirements.

Process of truing grinding wheel:

The principle of truing is mainly to use the hardness difference between the hardness of the abrasive grains in the sharpening tool, the abrasive grains of the grinding wheel, and the bond of the grinding wheel (the hardness of the abrasive grains of the sharpening tool is in the middle, the abrasive grains of the grinding wheel are the hardest, and the hardness of the bond is the worst) , The purpose of truing  is retain the abrasive and removing the bond.

The consolidated truing method is to use tools such as truing tools or oil stones to directly remove the bond, or to squeeze it with CBN abrasive grains to form crushed abrasive grains to fill in the gaps between abrasive grains, remove the bond, and form a chip space.

The dressing of hard abrasive grinding wheels is usually divided into two processes: truing and dressing. dressing is to carry out micro-cutting on the grinding wheel, so that the grinding wheel can reach the required geometric shape accuracy and the tip of the abrasive is finely broken to form a sharp grinding edge. Truing is to remove the bonding agent between the abrasive grains, so that there is a certain chip space between the abrasive grains, and the grinding edge protrudes beyond the bonding agent to form a cutting edge.

The grinding wheel has a self-sharpening effect during the grinding process, why should it be truing?

During the grinding process, the abrasive particles of the grinding wheel are gradually rounded and blunt under the action of friction and extrusion, or when grinding tough materials, the abrasive debris is often embedded in the pores on the surface of the grinding wheel, making the grinding wheel The surface is clogged, and finally the grinding wheel loses its cutting ability. At this time, slippage will occur between the grinding wheel and the workpiece, which may cause vibration and noise, which will reduce the grinding efficiency and deteriorate the surface roughness. At the same time, due to the increase of grinding force and grinding heat, it will cause work deformation and affect the grinding accuracy. In severe cases, burns and small cracks will appear on the grinding surface. In addition, due to the uneven hardness of the grinding wheel and the different working conditions of the abrasive grains, the working surface of the grinding wheel is worn unevenly, and the amount of abrasive grains falling off in each part varies, resulting in the loss of shape viscosity of the grinding wheel and affecting the shape accuracy and surface roughness of the workpiece surface.

Grinding wheel dressing method:

Grinding wheel dressing generally includes turning, diamond roller, grinding and rolling.

① Turning and dressing method: Using single-grain diamond (or diamond pen or diamond dressing block made of finely crushed diamond) as the cutting tool to turn the grinding wheel is the most commonly used dressing method.

②Diamond roller dressing method: Rotate at a certain speed (to reduce the relative speed between the roller and the grinding wheel), and produce grinding and rolling effects on the surface of the high-speed rotating grinding wheel, so that the grinding wheel can obtain a sharp working surface that matches the surface of the roller.

③ Grinding and dressing method of grinding wheel: use low-speed rotating grinding wheel to grind against high-speed rotating grinding wheel to achieve the purpose of dressing.

---EDITOR: Doris Hu

----POST:Doris Hu