Construction and Working of Plain Cylindrical Grinding Machine

Construction and Working of Plain Cylindrical Grinding Machine Points : Construction and Working of Plain Cylindrical Grinding Machine, Base, Table, Headstock, Footstock, Wheel-Head, Coolant System, Work Rest, Dressing the Wheel Plain cylindrical grinders are used for grinding the external cylindrical surfaces. They are used for producing plain or stepped external cylinders, tapers (conical), shoulders, concave or convex radii and undercuts.
By dressing the grinding wheel to the desired shape, from grinding can also 'be done. They range from light-duty to heavy-duty machines.

Construction Principal Parts of Cylindrical Grinding machine 1. Base The base gives rigidity and stability to the total machine and .supports the parts mounted on it. On the top of the base are carefully machined ways for the table to slide on, At the rear of the machine is a column on which the grinding wheel, wheel spindle, and wheel power unit are mounted. 2. Table The table has a machined surface on which the work-head and footstock that hold the work-piece are mounted. The table traverses back and forth on accurately machined ways to give movement of the work-piece past the grinding wheel, except in the case of plunge-cut grinding. The length of table traverse is controlled by trip dogs. These can be positioned in different places along the table to reverse the direction of table movement when the grinding wheel reaches each end of the work-piece. The table of this machine can be swiveled for slight tapers only. 3. Headstock The headstock or work-head is mounted on the left end of the table and cannot be swiveled. The work drive motor is incorporated in the headstock. Some jobs must be held on a faceplate others must be secured in a chuck or in a special fixture mounted on the spindle of the headstock. Most work to be ground cylindrically is held between centers. A drive plate is screwed on the spindle nose. A dog is fastened to the headstock end of the work-piece, which is mounted between centers, and engages a pin in the drive plate. The drive plate revolves about the headstock dead center and gives the work-piece its rotary motion. 4. Footstock The footstock is a unit similar to the one used on the lathe and can be adjusted and clamped in various positions along the table to take care of different lengths of work-pieces. The dead center in the spindle supports the work. 5. Wheel-Head The grinding wheel is mounted on the end of a spindle which revolves in a carefully constructed head. It is driven by an electric motor. In the plain cylindrical grinding, machine, the grinding wheel; unit (or wheel head as it is usually called) is mounted on a cross-slide at right angles to the ways of the table, but cannot be swiveled. At each reversal of the table and the work, the wheel is fed toward the work either by hand or automatically. Sometimes it can be fed across the work-piece. 6. Coolant System To control the sparks and abrasive dust of grinding so it does not fly around in the air of the room, and also to provide a coolant for the grinding action, a coolant storage tank, a pump, and piping are built into the machine to supply coolant to the wheel. An adjustable spout is supported near the face of the wheel above, the point of grinding contact in order to deliver the coolant at the proper place. 7. Work Rest Centers alone are often insufficient for supporting long pieces of work against the heavy pressure of the grinding wheel; Work rests or back rests are mounted at suitable intervals along the table. The hoes of the work rest oppose the outward and downward pressure of the wheel. Work rests may be spaced six to ten work diameters apart to prevent long, slender work-pieces from springing away from the pressure of the grinding wheel. Heavier work requires less support. 8. Dressing the Wheel On all cylindrical grinders, provision is made for dressing the wheel.