5RDSEMESTER- MECHANICAL ENGINEERINGSUBJECT MEC328/ ADVANCE MACHINE TOOLS METROLOGYKALASALINGAM UNIVERSITY Presented by Mr.I.RajkumarAPKALASALINGAM UNIVERSITY
Working Principle: The job is rigidly fixed on the machine table. The single point cutting tool held properly in the tool post is mounted on a reciprocating ram. The reciprocating motion of the ram is obtained by a quick return motion mechanism. As the ram reciprocates, the tool cuts the material during its forward stroke. During return, there is no cutting action and this stroke is called the idle stroke. The forward and return strokes constitute one operating cycle of the shaper.
CLASSIFICATIONThere are mainly two types of shapers:-Horizontal Shapers.I) Plain Shapers II) Universal Shapers.Vertical Shapers.Crank Shapers.Gear shapers.Hydraulic Shapers.Both shapers depending upon whether the ram and the cutting tool reciprocates in the horizontal plane or in the vertical plane.
Crank shapers are most commonly used. A rocker arm, operated by a crank pin from the main driving gear, gives the ram of the crank shaper a back-and-forth (reciprocating) motion.Gear shapersare driven by a gear and rack assembly. Gear shapers have a reversible electric motor or mechanical mechanism which quickly returns the ram, in readiness for another cut.Hydraulic shapers are driven by movement of a piston in an oil-filled cylinder. Mechanical features on these shapers are the same as those on crank shapers.
MAIN PARTS OF CRANK SHAPER
PRINCIPAL PARTS OF SHAPERBaseColumnTableCross RailRamTool Head
Base-The base is the necessary bed or support required for all machines tools. All other parts are mounted on and above the base. The bed takes up the total dead weight of the machine as well as the dynamic load during machining operations.Cross rail-The cross rail is mounted on the front of the body frame and can be moved up and down. The vertical movement of the cross rail permits jobs of different heights to be accommodated below the tool. Sliding along the cross rail is a saddle which carries the work table.Column-The column of the shaper is a hollow casting and is mounted on the base. It houses the drive mechanism for the ram and the table.
Table-The worktable of a shaper is fastened to the front of the column. The table moves across the column on crossrails to give the feed motion to the job.