mechanical project milling fixture
DESCRIPTION
NIE, Praveen, mechanical, engineering, project, work, fixture, millingTRANSCRIPT
"For an optimist the glass is half full, for a pessimist it's half empty,
and for an engineer is twice bigger than necessary."
At: PAMS Engineering, Mysore
Conceptualize a basic fixture configuration through
analyzing all the information.
Outputs:-
Fixture type and complexity
Number of workpieces per fixture
Orientation of workpieces within fixture
Clamping surfaces
Locating surfaces
Generation of fixture layout is to represent the fixtureconcepts in a physical form.
outputs:-
Position of locators
Position of clamps
Position of supports, if any
Types of clamps
Type of locators
Type of supports
• Fixture element design is to create the solid models ina CAD system of the practical embodiment of theconceptual locators, clamps and supports.
Outputs: -
Detailed design of locators
Detailed design of Clamps
Detailed design of supports
Tool body design is to produce a rigid structure
carrying all the individual fixture elements in their
proper places.
Design specifications
Factory standards
Ease of use and safety
Economy
Information gathering and analysis.
Consideration of clamping & locating schemes.
Design of fixture body.
Principle purpose of a machining fixture is to locate the
workpiece surfaces for performing a machining
operation
Surfaces to be distinguished
Active surfaces
Supporting & locating surfaces
Clamping surfaces
Free surfaces
Clamp
Device for providing an invariant location with respect to anexternal loading system.
Requirements of locking elements
To provide a suitable locking for achieving the
stability of location.
To provide sufficient frictional effects without
causing undesirable effect
Easy to manipulate manually or otherwise
Quick acting so as to reduce time setting clamping
and simultaneous locating
Inexpensive
Orientation of locators
Clamping force should be directed towards supporting and locating elements on overhanging or thin sections of the workpiece
classification of Clamping Elements
Type 1: elements in which the elastic deformationincreases with clamping force Ex: screws, levers, camsetc..,
Type 2: elements in which the clamping force assumesa constant value independent of the elastic deformationat the contact surface. Ex: Fixtures operated withhydraulic and pneumatic pressure
To provide a suitable locking for achieving the
stability of location.
To provide sufficient frictional effects without
causing undesirable effect