Ordinary cylindrical grinding is shown in the figure below. The top holes at both ends of the workpiece are used to support the workpiece between the headstock and the top of the tailstock of the grinding machine. During grinding, the workpiece rotates under the drive of the spindle, and the grinding wheel feeds laterally.
ordinary cylindrical grinding
▌ Centerless cylindrical grinding
Centerless cylindrical grinding has no headstock and tailstock, but supports the workpiece by a pallet and a guide wheel, and grinds it with a grinding wheel. The centerless grinding method is composed of three mechanisms: grinding wheel, adjustment wheel and workpiece support. The grinding wheel actually performs the grinding work. The adjustment wheel controls the rotation of the workpiece and makes the workpiece feed speed. The workpiece support is grinding. Support the workpiece when cutting. Centerless cylindrical grinders have higher productivity. It is mostly used in mass production and is easy to automate.
centerless cylindrical grinding
▌ The characteristics of centerless cylindrical grinding compared with ordinary cylindrical grinding
1. Continuous processing, no need to retract the tool, short time for clamping the workpiece, high productivity.
2. The bracket and guide wheel positioning mechanism have better supporting rigidity than the common cylindrical grinder's top and center frame mechanism, and the cutting amount can be larger, which is conducive to the processing of slender shaft workpieces, and is easy to achieve high-speed grinding and strong grinding.
3. The workpiece of the centerless cylindrical grinding machine is positioned on the positioning mechanism by the outer circle, and the grinding amount is the allowance on the diameter of the workpiece. Therefore, the wear of the grinding wheel, the compensation of the feeding mechanism and the repeated positioning accuracy error of the cutting mechanism have an impact on the dimensional accuracy of the diameter of the part. The impact is only half of that of ordinary cylindrical grinders, no center hole is required, and it is easy to automate loading and unloading in advance.
4. The centerless grinding machine with wide grinding wheel has a pass-through mechanism, which can increase the machining allowance each time. During plunge grinding, it can grind complex profiles sequentially or grind multiple grinding wheels, with high productivity and wide application range.
5. The centerless cylindrical grinder has no mechanism to ensure the relative position accuracy (coaxiality, verticality, etc.) of the grinding surface and the non-grinding surface, and the roundness is poor when grinding the circumferentially interrupted outer surface.
6. The grinding surface is prone to odd-numbered roundness, and if it is larger, it will often cause the illusion that the measured size is smaller than the maximum physical size, which will affect the assembly quality and work performance.
7. The adjustment of the machine tool is complicated and time-consuming. Every time the workpieces of different diameters are replaced, the height of the bracket, the distance and the related process parameters need to be adjusted. Therefore, it is difficult to adjust the technology, and it is not suitable for small batch and single-piece production.
