FIXTURE DESIGNING

RAHUL TALELEVIT PUNE

FIXTURE

Fixture is a work holding and support device used in the manufacturing industry.

Fixture is used to securely locate ( position in specific location or orientation ) and support the work, ensuring that all parts produced using the fixture will maintain conformity and interchangeability.

Purpose of Fixture

A fixture’s primary purpose is to create a secure mounting point for a work piece, allowing for support during operation and increased accuracy, precision, reliability, and interchangeability in the finished parts.

FIXTURES MUST ALWAYS BE DESIGNED WITH ECONOMICS IN MIND; THE PURPOSE OF THESE DEVICES IS TO REDUCE COSTS, AND SO THEY

MUST BE DESIGNED IN SUCH A WAY THAT THE COST REDUCTION OUTWEIGHS THE COST OF

IMPLEMENTING THE FIXTURE. IT IS USUALLY BETTER, FROM AN ECONOMIC STANDPOINT, FOR A FIXTURE TO RESULT IN A SMALL COST REDUCTION

FOR A PROCESS IN CONSTANT USE, THAN FOR A LARGE COST REDUCTION FOR A PROCESS USED

ONLY OCCASIONALLY.

DESIGN

LOCATION Locating components ensure the geometrical stability of the work piece . They make sure that the workpiece rests in the correct position and orientation for the operation by addressing and impeding all the degrees of freedom the work piece possesses.For locating work pieces, fixtures employ pins (or buttons), clamps, and surfaces. These components ensure that the work piece is positioned correctly, and remains in the same position throughout the operation. Surfaces provide support for the piece, pins allow for precise location at low surface area expense, and clamps allow for the workpiece to be removed or its position adjusted. Locating pieces tend to be designed and built to very tight specifications.

SUPPORTIn designing the locating parts of a fixture, only the direction of forces applied by the operation are considered, and not their magnitude. Locating parts technically support the workpiece, but do not take into account the strength of forces applied by the process and so are usually inadequate to actually secure the workpiece during operation. For this purpose, support components are used.To secure workpieces and prevent motion during operation, support components primarily use two techniques: positive stops and friction. A positive stop is any immovable component (such as a solid surface or pin) that, by its placement, physically impedes the motion of the work piece.

PROBLEM STATEMENT

Manufacture a fixture to hold and support two rectangular ( 20*10*5) work piece accurately to drill a hole on joint .After joining that two work piece it will be square of (20*20*5)Remove that work piece without disturbing the alignment of both rectangular work piece with centered hole .

IMPORTANT CONSIDERATIONS WHILE DESIGNING JIGS AND FIXTURES Designing of fixtures depend upon so many factors . These factors are analysed to get design inputs for fixtures . The list of such factors is mentioned below: Study of workpiece and finished component size and geometry .Type and capacity of the machine, its extent of automation.Provision of locating devices in the machine.Available clampin arrangements in the machineAvailable indexing devices, their accuracy.Evaluation of variability in the performance results of the machine.Rigidity and of the machine tool under consideration.Study of ejecting devices,safety devices ,etc.Required level of the accuracy in the work and quality to be produced.

What Should be Done…?

Collect the information regarding with Fixture ( Books & Internet )

Paper work ( Dimensioning ) based on Problem Statement.

Search the various mechanisms for motion of Fixture.

Learn to assemble a Fixture. Prepare the 3D model on CATIA. Search the Materials for Manufacture . Make a proto-type for Fixture. Use different mechanisms to actuate the Fixture. Actual manufacture of Fixture.

3D Model in Catia

MECHANISM FOR ACTUATION OF FIXTURE

Fixture mechanism.mp4

MANUFATURED MODEL

USESFixture is used to securely locate ( position in specific location or orientation ) and support the work, ensuring that all parts produced using the fixture will maintain conformity and interchangeability. A fixture’s primary purpose is to create a secure mounting point for a work piece, allowing for support during operation and increased accuracy, precision, reliability, and interchangeability in the finished parts.

THANK YOU…