Holding Devices PDF

HOLDING DEVICES 1 CONTENTS Holding device introduction Bench vice Lathe machine holding device Milling & Drilling machine holding device Cutter holding device Jigs & Fixture Safe handling method 2 WHAT IS HOLDING DEVIC...

HOLDING DEVICES 1 CONTENTS Holding device introduction Bench vice Lathe machine holding device Milling & Drilling machine holding device Cutter holding device Jigs & Fixture Safe handling method 2 WHAT IS HOLDING DEVICE A device used to position and hold a work piece. The work holding device references the tool performing the operation on the part being held. The process of securely supporting, locating, and clamping a work piece for a manufacturing operation. 3 HOLDING DEVICE PICTURES 4 BENCH VICE A holding device attached to a workbench; has two jaws to hold work piece firmly in place 1 – Handle 2 – Box nut 3 – Base 4 – Fixed jaw 5 – Movable jaw 5 TYPES OF BENCH VICE 6 LATHE MACHINE HOLDING DEVICE All four jaws chuck move independently Rectangular shape job can also be clamped Suitable for eccentric turning 1. Any type of work piece can be held easily 2. High grip is possible as four jaws are employed 1. Centering is a little difficult process 2. Semi skilled labor are required 7 LATHE MACHINE HOLDING DEVICE Three jaw chuck or self-centering chuck is the chuck, which has three jaws for holding the work piece and if one jaw is moved then all the other jaws also move by same distance Suitable to only to clamp round job Centering process is not necessary as all the jaws moves at a time Consumes less time for mounting and un mounting the work piece. Grip is not so high as only three jobs are employed All type of jobs cannot be mounted on these chucks, as they are useful in machining only axis symmetrical objects. 8 LATHE MACHINE HOLDING DEVICE Lathe steadies or rests 9 LATHE MACHINE HOLDING DEVICE Mandrels are used to hold work pieces which are already bored. Work pieces are mounted on mandrels, and the external operations are carried out with respect to the bore. 10 LATHE MACHINE HOLDING DEVICE Drill chuck This chuck is used for holding the tool in the drilling machines. This also plays a role in holding taper shanks on a lathe for easy machining of the job on which holes are to be drilled. 11 MILLING & DRILLING MACHINE HOLDING DEVICE Basic production machine operation & controls Work holdings Work holding devices are used, to hold the jobs or work pieces rigidly on table for milling operations. Some of the work holding devices generally used on milling & Drilling machines : 1. Vices 2. T-Bolts and nut. 3. Clamps 4. V-blocks with clamps 5. Base chucks 12 MILLING & DRILLING MACHINE HOLDING DEVICE 1. Vices Types: 1. Plain vices 2. Swivel base vices 3. Universal vices 4. All steel vices Plain Vices 5. Air operated vices Universal Vices Swivel base Vices 13 MILLING & DRILLING MACHINE HOLDING DEVICE All steel Vices Air operated Vices (Pneumatic) 14 MILLING & DRILLING MACHINE HOLDING DEVICE 2. T - bolts & Nuts 15 MILLING & DRILLING MACHINE HOLDING DEVICE 3. Clamps Plain Goose neck Clamp set Strap 16 MILLING & DRILLING MACHINE HOLDING DEVICE 3. Uses of Clamps Strap 17 MILLING & DRILLING MACHINE HOLDING DEVICE 4. V blocks with clamps Steel V – Block Magnetic V- Block (Non magnetic) Used for supporting of round and square jobs Used for clamping of round and during Light machining, Grinding, Drilling & flat jobs during operation, Light Inspection. Can also be used for end face, machining, Grinding or Drilling & side face and right angle Grinding. Inspection. 18 CUTTER HOLDING DEVICE Cutter holding devices are mounted on milling machine spindle.They are used to hold the cutters and to drive. Types: 1.Short arbor 2.Long arbor 3.Collet adopter 4.Drill chuck adopter 5. Face mounting cutters a : Drive lugs b : Drive slot c : Retaining screw 19 CUTTER HOLDING DEVICE 2. Long arbor A type B type 20 CUTTER HOLDING DEVICE 3. Collet adopter Collet chuck 21 CUTTER HOLDING DEVICE 5. Face mounting cutters a)Drive lugs b)Bolts c)Facing cutters d)Hub 22 JIGS & FIXTURE Jigs A customized work holding device used to position and hold a work piece while guiding the location of the cutting tool. Jigs are not as common as fixtures and are not used with CNC machines. The jigs are made of hardened steel, which are wear resistant, corrosion resistant, thermally in sensitive. Their dimensional accuracy directly influences the accuracy of performance of the operation where these are used. Advantages of Jigs 1. Alignment of a part or work piece. 2. Securing the part or work piece. 3. Duplication of a process. 4. Maintain or improve part quality. 5. Increase productivity. 6. Reduce cost of production. 7. Improve overall safety to the part, the operator, and the machine. 23 HOLDING DEVICE Fixture Fixture is a holding and locating device. It is used to hold the component and locating the job There are 3 types of Fixture 1. Production Fixture - P Used to hold & locate the Cylinder component during operation, it Cylinder is placed on the machine table. Cylinder Advantages Cylinder Productivity improvement Quality improvement High Operator safety Tool life improvement On time delivery 24 HOLDING DEVICE 2. Acceptance Fixture - A Used to measure the parameters which are difficult to measure using standard measuring instruments. Acceptance fixture does not give the actual value. It says whether the parameter inspected is within the tolerance limit. Advantages Less Inspection time Productivity improvement Quality improvement Easy to inspect the product 25 HOLDING DEVICE 3. Inspection Fixture - I It is used along with the standard measuring instrument such as Height gauge or dial indicator which in turn indicates the actual measured value. Advantages Exact reading can be seen Quality improvement Customer complaint can be reduced 26 HOLDING DEVICE Fixture Identification Example:- BACR 1016 P 45 239 – 03 ❑ BA : Customer name (Bajaj Auto Limited) ❑ CR : Product name (Connecting rod) ❑ 16 : Product (Part) number ❑ P : Type of fixture (Production fixture) ❑ 45 : Process Number ❑ 239 : Fixture model number ❑ 03 : Fixture serial number 27 HOLDING DEVICE Fixture setting procedure Select the required Fixture Clean the machine table & Fixture base Fix the Fixture on the machine table Dial the Fixture within 0.01 mm Tighten the nut with the help of suitable ring spanner Connect the pneumatic or hydraulic hose if it is required 28 SAFE HANDLING METHOD Keep the device clean & apply thin layer of oil or Greece whenever required. Keep the device in proper place. Should not play with device & handle with care. Ensure there corners free from sharp edges, burrs…etc Maintain identification of holding devices for easy handling. Maintain safe height to place work holding devices 29