What is a grinding?
The process of chipping, in which the removal of extra material on the part is performed by abrasion, is called grinding. In this process, each of the abrasive grains placed on the surface deforms a small part of the workpiece. Grinding operation is usually the last stage of work on the part and after doing it, the quality of the work surface increases. Various forms of stones and pieces are used in grinding operations, and this process depends on the shape of the piece, the size of the piece, the ease of fixing and the required production rate according to its specific application.
Applications of grinding
When the goal is to reduce the thickness of the piece, the grinding method will be very useful; In fact, grinding is a type of surface treatment. The possibility of removing parts in this method reaches 0.025 micrometers, which is done by sanding; Therefore, the dimensions of the parts that are produced by this method are highly accurate and produce the final part with excellent quality.
How to do grinding operations
Dressing is a process of sharpening and correcting the angles of the grinding wheel as well as cleaning its surfaces, which is used for all stone wheels, except for plated stones. In addition, hard particles such as silicon carbide or aluminum form the grinding medium, which are usually glued together with a retainer. A rotating motor with adjustable speed and a workpiece holding bed inside the fixture are the components that make up the grinding machine.
The stone head can be fixed or movable for the workpiece. This machine also produces significant heat during the wear operation of the desired piece. Therefore, a cooler is installed in it so that the temperature does not exceed the tolerance of the workpiece. This heat is sometimes so hot that even the coolant burns. If the accuracy in grinding is set to about 200 nm, little heat is produced that does not require cooling. This method of machining solutions is very important in the field of manufacturing engineering parts.
Grinding processes
Grinding operations are performed with various shapes of stone and work piece. Choosing a grinding process for a specific application depends on the shape of the piece, the size of the piece, the ease of fixing and the required production rate. It is on this basis that different types of grinding operations can be investigated. These processes are:
1- Flat grinding
One of the most common operations in grinding machines is flat grinding, which is performed on flat surfaces. When performing this operation, the magnetic system is placed on the table of the flat grinding machine and the workpiece is attached to one end. To fasten non-magnetic materials, clips, special fixtures, double-sided adhesive tapes are usually used, or they are tied to the table with the help of a system. After that, a flat round sanding stone is installed on the horizontal axis of the machine.
By going back and forth with this sanding stone along the length of the table and progressing on the piece, transverse grinding is done after each back and forth. In another method of flat grinding, reed grinding is done inside. In this method, the sanding stone moves radially towards the workpiece as if it were a grinding groove. In this type of method, according to the dimensions of the surface on which grinding can be done, the size of the flat grinding machine will be determined.
2- Cylindrical grinding
This method is known as axis grinding or bird type. Because in this operation, the outer cylindrical surface and shoulders of the workpiece are ground. Crankshaft bearings, spindles, pins, ring bearings and rollers of rolling machines are among the applications of cylindrical grinding. In this device, a rotating cylindrical part moves back and forth along its axis.
It can also grind rollers with diameters as large as 1.8 meters. Between two birds or a system is the position of the work piece or this piece is connected to a system plate in the head of the machine. After that, the axis of the stone and piece are moved at different speeds by separate motors. In the axial grinding method, it is possible to grind long workpieces with two or more different diameters. On the other hand, in the operations where the stone is sharpened into pieces with shape stones, the desired shapes can be shaped by cylindrical grinding.
3- Internal grinding
4- grinding without chicken
One of the mass production processes for continuous grinding of cylindrical surfaces is grinding without a bird. In this type, the work piece is held without two birds or any other system. This piece of work will be closed by a blade. Work pieces such as roller bearings, engine valves, camshafts, etc. are produced without hinges.
5. Created grinding
A process of grinding that is accompanied by chipping operations with low tracks and fine finishing is called creep grinding. In addition, they use this method for large-scale metal cutting operations such as milling, turning, and gate turning. Special features such as high power, high vibration capacity, variable speeds of the axis of the work table and high capacity of grinding liquids are unique features for creep grinding machines. Also, today they use stones that have the ability to continuously sharpen the sanding stone with diamond rollers.
