The present invention relates to machine tools in general, and more particularly to improvements in machine tools of the type wherein the workpiece or workpieces and/or the tool or tools must be cooled by sprays or jets of liquid coolant during removal of material from and/or during other treatment of the workpieces. Typical examples of such machine tools are grinding machines, such as surface or circular grinding machines.
A circular grinding machine normally comprises a base or bed which carries the work holding members (such as a headstock and a tailstock) and also the tool supporting unit, e.g., a carriage for the spindle of a grinding wheel. The base is normally a block-shaped component with a horizontal top surface for the tool supporting unit. The latter can be fixedly mounted on the base or it is mounted for movement in the direction of the Z-axis. It is also customary to install a carriage-table system in front of the tool supporting unit and to provide the carriage-table system with a headstock and a tailstock as a means for holding of a selected workpiece during removal of material therefrom. The carriage-table system is movable in the direction of the Z-axis, i.e., at right angles to the X-axis and parallel to the axis of the grinding wheel in the tool supporting unit.
A drawback of the above outlined conventional grinding machines is that the liquid coolant, which is used in large quantities to prevent overheating of the workpiece(s) and/or tool(s), descends onto the horizontal top surface and thereby greatly influences the temperature of certain portions of the base, especially in the regions which can affect the quality of treatment of workpieces. The body of coolant which accumulates on the top surface of the base is likely to dwell there for extended intervals of time unless forcibly wiped away or unless replaced with freshly sprayed coolant. Moreover, the so-called slime or mud which develops during grinding also accumulates on the top surface of the base and must be removed by hand in a time-consuming operation. The non-uniform changes in the temperature of the base adversely affect the quality of the treatment, i.e., the accuracy of finish of the workpieces