Definition of cylindrical grinding machine
The grinding machine features a cylindrical, conical, or other shaped outer surface, along with a shoulder end.
To begin the grinding process, the workpiece is positioned between the two tips of the head frame and the tailstock. The head frame’s dial rotates the workpiece, creating circular feeding motion.
Both the headstock and tailstock are mounted on the workbench, allowing for longitudinal reciprocating feed motion.
The workbench is divided into two layers – upper and lower. The upper workbench can be adjusted to a slight angle, enabling the grinding of conical surfaces.
Working mode and parameters
The wheel frame with a high-speed rotating grinding wheel is utilized for lateral feed movement.
To minimize the length of the machine tool, the large cylindrical grinding machine is typically secured, and the grinding wheel frame is utilized for both longitudinal reciprocating motion and lateral feeding motion.
Regarding the cylindrical grinding machine’s grinding precision, the roundness typically does not exceed 3μm, while the surface roughness Ra ranges from 0.63μm to 0.32μm. The high-precision cylindrical grinding machine, however, can achieve a roundness of 0.1μm and Ra of 0.01μm, respectively.
Cylindrical grinding machine classification
The cylindrical grinding machine comes in three types – plunge-type cylindrical grinding machine, universal cylindrical grinding machine, and end-face external grinding machine.
① Plunge cylindrical grinder
When the length of the grinding part of the workpiece is less than the width of the grinding wheel, the grinding wheel only needs to be continuously fed in the transverse direction and does not have to move relative to the workpiece in the axial direction. This type of grinding machine offers high productivity.
② Universal cylindrical grinding machine
This type of grinding machine comes with an internal grinding accessory that can be attached to the wheel frame. The wheel frame and the head frame can be adjusted to a certain angle around the vertical axis. In addition, the spindle can also be rotated on the head frame via the dial. This kind of grinding machine can enlarge the processing range, grind the inner hole and the inner and outer taper with a large taper, and is suitable for small and medium batch as well as single-piece production.
③ End cylindrical grinding machine
The wheel frame is inclined at an angle around the vertical axis, and the surface of the grinding wheel is trimmed into two grinding faces parallel and perpendicular to the workpiece axis. This type of grinding machine allows simultaneous grinding of the outer circle and the shoulder end face of the workpiece, making it ideal for mass production.
Moreover, there are high-efficiency double-wheeled cylindrical grinding machines and multi-grinding cylindrical grinding machines that can grind two or more journals simultaneously for high-volume production.
Grinding movement of cylindrical grinding machine
When performing cylindrical grinding using a cylindrical grinding machine, there are several types of movement involved:
- The main motion for grinding the outer circle is the high-speed rotary motion of the grinding wheel.
- The longitudinal feed motion of the outer circle is achieved through the longitudinal reciprocating motion of the workpiece with the table.
- The circumferential feed motion of the grinding outer circle is achieved through the rotation of the workpiece by the headstock spindle.
- The grinding wheel also makes a periodic lateral feed motion.