Presentation on theme: "Work Holding and Tool Holding"— Presentation transcript:
1Work Holding and Tool Holding Six degrees of freedom of a body/object in spacePrinciple of work/tool holding (location and restraint)Example of work holding method
2Six degrees of freedomIf we consider a body/object in space it is free to move in six directions as follows:Back and forth along the X axisSide to side along the Y axisUp and down in the Z axisRotate either way about the X axisRotate either way about the Y axisRotate either way about the Z axis
3Principle of location and restraint To be able to carry out work on the material/object it is necessary to locate the material in a set position on the machine and restrain it using some form of clamping/fixing device to prevent any linear or rotational movement.The clamping/fixing devices can consist of:(A) positive restraints, where a physical object prevents the material from moving.(B) frictional restraints, where the material is gripped between two or more objects.(C) a combination of positive and frictional restraints.Where possible a positive restraint should be used to resist cutting forces.
4Location and Restraint If the material is placed on a flat surface as in diagram below some of its states of freedom become restrained
5When location pins are added as in diagram below it becomes further restrained and also located in set positions
6If clamping screws are then added as in diagram below the material becomes fully restrained and located in set positions
7Typical Example of a Work Holding Device (work held between centres on a lathe)