Method of cylindrical grinding

1. Longitudinal grinding method

Longitudinal grinding method is a common grinding method. During grinding, the worktable is fed longitudinally and repeatedly, the grinding wheel acts as periodic transverse feed, and the grinding allowance of the workpiece is ground off in multiple reciprocating strokes.

Characteristics of longitudinal grinding method (longitudinal method for short).

① In the whole width of the grinding wheel, the working conditions of the abrasive grains are different. The sharp corner on the left end of the grinding wheel bears the main cutting effect. The grinding allowance of the workpiece is cut off by the abrasive grains at the corner of the grinding wheel, and most of the abrasive grains on the width of the grinding wheel bear the role of reducing the surface roughness of the workpiece. The longitudinal grinding method has good grinding force and heat dissipation conditions, and can obtain higher machining accuracy and smaller surface roughness.

② Labor produces low efficiency.

③ Small grinding force, suitable for grinding slender, precision or thin-walled workpieces

2. Cut in grinding method

Cut in grinding method, also known as transverse grinding method, the length of the outer circle of the workpiece to be ground shall be less than the width of the grinding wheel. During grinding, the sand wheel shall make continuous or intermittent transverse feed movement until all the allowance is removed. There is no longitudinal feed movement during grinding, and a higher cut in speed can be used during rough grinding; During fine grinding, the cutting speed is low to prevent workpiece burn, heating and deformation.

Characteristics of cut in grinding method;

① The workpiece with abrasive grains on the whole grinding wheel width is the same, giving full play to the grinding role of all abrasive grains. At the same time, due to the continuous transverse feed, the basic grinding time is shortened, so it has high productivity.

② The radial grinding force is large, and the workpiece is prone to bending deformation. Generally, it is not suitable for grinding finer workpieces.

③ Large grinding heat is generated during grinding, and the workpiece is easy to burn, heat and deformation.

④ The shape of the grinding wheel surface will be copied to the workpiece surface and affect the surface roughness. In order to eliminate the above defects, a small lateral movement can be made at the end of the cutting method.

⑤ Due to the limitation of the width of the grinding wheel, the cutting method is only used to grind the cylindrical surface with short length.

3. Segmented grinding method

Rough grinding is carried out in sections, leaving 0.03-0.04mm. After the allowance, the longitudinal method is finely ground to the size. This grinding method not only makes use of the advantages of high production efficiency of the cut in method, but also has the advantages of high machining precision of the longitudinal method. During sectional grinding, there shall be an overlap of 5-10mm between two adjacent sections. This grinding method is suitable for workpieces with good grinding allowance and rigidity, and the length of workpieces should be appropriate. Considering the grinding efficiency, a wider grinding wheel should be used to reduce the number of segments. It is preferred when the length of the machined surface is about 23 times the width of the grinding wheel.

4. Deep grinding method

This is a widely used grinding method, which uses a large back draft to grind all the grinding allowance of the workpiece in one longitudinal feed. Because the basic grinding time is shortened, the labor productivity is high.

Characteristics of deep grinding method:

① It is suitable for grinding workpieces with good rigidity

② The grinder shall have high power and stiffness.

③ Small single direction longitudinal feed shall be adopted during grinding. The longitudinal feed direction of the grinding wheel shall face the head frame and lock the tailstock sleeve to prevent the workpiece from falling off. The grinding wheel shall have moderate hardness and good grinding performance.

2、 Grinding method of step surface

After grinding the outer circle, the step surface of the workpiece can be ground by moving the worktable by hand and borrowing the end face of the grinding wheel. During grinding, it is necessary to withdraw the grinding wheel slightly horizontally, manually rotate the workbench, make intermittent feeding after the grinding wheel contacts the end face of the workpiece, and pay attention to pouring sufficient cutting fluid to avoid burning the workpiece. Generally, the end face of the grinding wheel can be trimmed into an inner concave shape to reduce the contact area between the grinding wheel and the workpiece and improve the grinding quality.