Design of Milling Fixture

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  • Topic: Machining, Fastener, Screw
  • Pages : 5 (713 words )
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  • Published : January 17, 2011
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DESIGN OF MILLING FIXTURE

FINISHED COMPONENT

Sequence Of Operation 1. Milling of Reference Surfaces A & B.

B

A C

2. Turning of hole C

C

3. Milling 50 x 15

Milling

50 x 15

Design

Principle of Design
üLocation ü üClamping ü üLoading & Unloading

Location
üLocation is done using 3-2-1 locating principle. üSurfaces A, B, & C are used for locating purpose. üLocating pads, Ring, Cams & pin are used to located surface A, B, C on the fixture, to increase the accuracy of the workpiece.

Clamping

Strap Clamp

C - Washer

Loading
1.Loosen the strap clamps. 2. 3.Place the job on the V – block and locate it on three surfaces. 4. 5.Align the job by adjusting the cams and then tighten the strap clamp in 90 º. 6. 7.Then place the C – washer on the pin and tight it with help of nut. 8. 9.See that all the fasteners are secured, so as to maintain the accuracy of workpiece.

Unloading
1.Loosen the Strap clamps. 2. 3.Loosen the nut, remove the C – Washer. 4. 5.Loosen the cam & remove the workpiece.

Parts
QTY

1.Base plate 2.Angle Plate 3.V – Block 1 4.Cams 2 5.Strap Clamps 2 6.Ring 1 7.C – Washer 8.Resting Pad 2 9.Nut 1 10.Dowel 6 11.Soc. Headed cap screw 12.Setup block 13.Tenon 2

1

1

1

1

8

Base Plate

1.Base plate is made out of cast iron. 2.The Boss is provided for clamping on the machine table. 3.Holes have been drilled for fixing angle plate & setup block.

Angle Plate
1. Angle plate is made up of cast iron having two faces at right angle to each other. 2. Pin has been welded for locating the workpiece. 3. Holes is provided for strap clamps & for cams. 4. Also holes are provided for clamping V – block.

V - Block

1.The V – Blocks are used for holding round workpiece. 2. 3.V – Blocks are accurately machined and made up of cast iron & steel.

Cams
1.When there is a

considerable variation in workpiece dimension from batch to batch an eccentric locator or cam can be used. 2. 3.The eccentricity rotating it. of the cam can be varied by

Strap Clamp
1.These are made of rectangular plates and acts like levers. 2. 3.The clamp is tightened by rotating an hexagonal nut. 4. 5.One end of clamp presses against the workpiece. 6. 7.It take care of any variation in workpiece.

C - Wa s h e r

1.Simple & quick in operation. 2. 3.The slot permits removal of the C – Washer after a slight loosening of hexagonal nut.

Resting Pad

1.Resting pads locate the component and supports the component. 2. 3.It also helps in swarf removal.

Dowel

1.Dowels 2.

are

used

for

locating purpose. 3.They are placed as far as possible.

Soc. Headed Cap Screw

1. This are meant for fastening purpose.

Ring

1. It Supports the component .

Nut

1. It use for tightening the workpiece securely in the fixture.

Setup Block
1.Suitable pieces provided 2. 3.Gap of 0.4 – 0.5mm facilitates cutter setting with the help of the feeler gauge. cutter should for easy setting be &

accurate tool setting.

Te n n o n s
1.Milling fixture are generally fixed with locating tennons. 2. 3.These are fixed in slots machined on the resting face on the base. 4. 5.Tennons are made close sliding fit in machine T – Slot. 6. 7.Tennons align milling fixture with the longitudinal stroke of the machine.

Screw

1. This are meant for fastening purpose.

Assembly
1.Assembly of V – block in angle plate. 2.Screwing the V – block in the angle plate. 3.Assembly of angle plate in the base plate. 4.Doweling of angle plate in base plate. 5.Screwing the angle plate into base plate. 6.Screwing the cams to the angle plate. 7.Assembly the strap clamp to the angle plate. 8.Assembly the ring on the pin. 9.Press fit the resting pads on the angle plate. 10.Screwing & doweling the setup block. 11.Screwing the tennon to the bottom of the base plate. 12.

Assembly

THANK YOU

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