WITH EFFECT FROM THE ACADEMIC YEAR 2013 - 2014

ME 454

MACHINE TOOL DESIGN

(ELECTIVE - II)

Instruction                                                                                                                                                                          4    Periods per week

Duration of University Examination                                                                                                                                      3    Hours

University Examination                                                                                                                                                       75    Marks

Sessional                                                                                                                                                                            25    Marks

Unit-1

Classification of machine tools. Mechanisms used for converting rotary to linear motion and intermittent motion. Kinematic structures of machine tools - general purpose, special purpose, automatic screw cutting machines. Basic features of transfer machines. Numerical Control of machine tools, advantages and limitations. Schematic diagrams of NC systems.

Unit-II

Drives of machine tools; selection of range of speeds and feeds. Speed layout in GP, AP and logarithmic progression. Standardization of speeds and feeds. Productivity loss.

Selection of highest and lowest speeds, range ratio. Design of ray diagram and structural diagrams for machine tool gear boxes. Determination of number of teeth and module of gears in gear box design. Rules for layout of gear box having sliding clusters. Sliding cluster and clutched drives, Ruppert drive.

Unit-III

Feed gear boxes: Norton and Meander gear boxes. Stepped and step less regulation of speeds.

Strength and Rigidity design analysis. Design of beds, frames, Columns and Guide ways.

Materials for structures. Methods to improve the rigidity of structures. Overall compliance of machine tool. Thermal effects - functional accuracy of machine tool.

Unit-IV

Spindle units; Spindles of lathe, Drilling, Milling and Grinding machines materials for spindles. Spindle design. Effect of clearance on the rigidity of spindle.

Hydro-dynamic and Hydro-static bearings; Requirements of spindle bearings.

Unit-V

Hydraulic controls: various controls used in machine tools. Hydraulic and Pneumatic systems used in machine tools. Positive displacement pumps. Power pack. Relief valves, check valves, flow control valves, multi position direction control valves, Filters, Accumulators. Speed regulation of surface grinding machine. Hydro- copying systems.

Suggested Reading:

1. 1.G C Sen & Bhattacharya, Principles of machine tools, New Central Book Agency, Calcutta.

1. 2.N K Mehta, Machine Tool Design and Numerical Control, Tata McGraw-Hill Publishing co. Ltd.

1. 3.S.K.Basu, Design of machine tools, Allied Publishers

1. 4.S R Majumdar, Hydraulic Systems- Principles & Maintenance, Tata Mc.Graw-Hill Publishing Company Limited; New Delhi