Tilting Vice.doc

LIST OF SYMBOLS

Ø

–

Diameter

M

-

Metric units

dc

-

Coarse diameter

d

-

Diameter

ft

-

Tensile stress

fs

-

Shear stress

P1

-

Initial tension

P

-

Load

*

-

Multiplication

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DESIGN AND FABRICATION OF TILTING VICE ABSTRACT Generally vice is a common device used to hold work for carrying out various operations due to quick loading and unloading capability. Tilting vice is a device used on the shop floor holding the job during machining operation at various angle. Tilting vice provides various angular position to make the angular machining of milling machine. It is generally clamped with two pressure pads. The two jaws are holding the job very rigidly. Angle holding double jaw vice can also be used for all kind of machining operation. MAIN OBJECTIVE

 In this concept the tilting vice is very useful in drilling machine, milling machines, grinding machines etc..,  This is the small machine attachments which we have designed specially for all machine.  By this attachment we can do lot of operation in different machine  Some complicated components needs differed type of drilling holes and milling operation.  So designing the separate fixture for holding in such machines is much cost.  So this tilting vice attachments shows the most important in machines.  Vices usually have one fixed jaw and another, parallel, jaw which is moved towards or away from the fixed jaw by the screw.

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1. PROJECT PLANNING

Before starting every project its planning is to be done. Planning is very important task and should be taken with great care, as the efficiency of the whole project largely depends upon its planning while planning a project each and every details should be worked out in anticipation and should carefully is considered with all the relating provisions in advance. Project planning consists of the following steps.

PROJECT CAPACITY The capacity of the project must be decided considering the amount of money which can be invested and availability of material and machines.

DRAWINGS Drawing been decided for the project to be manufacture. Its detailed drawing specification for raw material and finished products should be decided carefully along with the specification of the machines required for their manufacture.

MATERIAL EQUIPMENT The list of materials required for manufacture is prepared from the drawings. The list of is known as “BILL OF MATERIALS”. This passes to the store keeper 3

and the required materials taken from the store under permission of store keeper operation, the necessity of operation, the person to do the job, machine to be used to do the job are considered while planning the operation. After considering tea above questions a best method is developed and the best method is applied to the operation. MACHINE LOADING While planning proper care should be taken to find the machining time for each operation as correct as possible. So that the arrangement for full utilization of machine can be made machine loading programmed is also known. PURCHASE CONSIDERATION It is different to manufacture all the component needed for the equipment in the workshop it self. The decision about a particular item whether to purchase or to manufacture is taken by planning after making through study of relative merits demerits. EQUIPMENT CONSIDERATION Result obtained from “PROCESS PLANNING” and “MACHINE LODING” helps in calculating the equipment requirement specification of the equipment should be laid down by considering the drawing. Drawing will also help in deciding and necessary requirement of tools, accessories. COST CALCULATION

The cost of the project can be calculated by adding following. 1. Material Cost 2. Machining Cost 4

3. Overhead Expenses.

COMPARISION The various items in the finished project are compared to the standards for the further correction. REPORT At the end of the project work report is prepared for future references. The report consists of all the items done the project work.

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2.VARIOUS VICE IN ENGINEERING FIELD

Vise

A vise or vice (see American and British English spelling differences) is a mechanical screw apparatus used for holding or clamping a work piece to allow work to be performed on it with tools such as saws, planes, drills, mills, screwdrivers, sandpaper, etc. Vises usually have one fixed jaw and another, parallel, jaw which is moved towards or away from the fixed jaw by the screw.

Types Without qualification, "vise" usually refers to a bench vise with flat, parallel jaws, attached to a workbench. There are two main types: a woodworking vise and engineer's vise. The woodworker's bench vise main characteristic is its integration 6

into the bench. An engineer's bench vise is usually clamped or bolted onto the top of the bench.[1] Woodworking vises

Woodworker's vise For woodworking, the jaws are made of wood, plastic or from metal, in the latter case they are usually faced with wood to avoid marring the work piece. The top edges of the jaws are typically brought flush with the bench top by the extension of the wooden face above the top of the iron moveable jaw. This jaw may include a dog hole to hold a bench dog. In modern metal woodworkers' vises, a split nut is often used. The nut in which the screw turns is in two parts so that, by means of a lever, it can be removed from the screw and the moveable jaw can be quickly slid into a suitable position at which point the nut is again closed onto the screw so that the vise may be closed firmly onto the work.

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Engineer's vises

A machine vise on a rotary table

Engineer's bench vise or fitter's vise - image inset shows soft jaws

A small machine vise used in a drill press An engineer's vise, also known as a metalworking bench vise or fitter's vise, is used in metalworking applications. The jaws are made of soft or hard metal. The 8

vise is bolted onto the top surface of the bench with the face of the fixed jaws just forward of the front edge of the bench. The bench height should be such that the top of the vise jaws is at or just below the elbow height of the user when standing upright. The vise may include other features such as a small anvil on the back of its body. The nut in which the screw turns may be split so that, by means of a lever, it can be removed from the screw and the screw and moveable jaw quickly slid into a suitable position at which point the nut is again closed onto the screw. The disadvantage to this system is lower precision, as compared to a solid screw system. Vise screws are usually either of an Acme thread form or a buttress thread. Those with a quick-release nut use a buttress thread. Some vises have a hydraulic or pneumatic screw, making setup not only faster, but more accurate as human error is reduced For large parts, an array of regular machine vises may be set up to hold a part that is too long for one vise to hold. The vises' fixed jaws are aligned by means of a dial indicator so that there is a common reference plane. For multiple parts, several options exist, and all machine vise manufacturers have lines of vises available for high production work: 

The first step is a two clamp vise, where the fixed jaw is in the center of the vise and movable jaws ride on the same screw to the outside.



The next step up is the modular vise. Modular vises can be arranged and bolted together in a grid, with no space between them. This allows the greatest density of vises on a given work surface. This style vise also comes in a two clamp variety. 9

Tower vises are vertical vises used in horizontal machining centers. They



have one vise per side, and come in single or dual clamping station varieties. A dual clamping tower vise, for example, will hold eight relatively large parts without the need for a tool change. Tombstone fixtures follow the same theory as a tower vise. Tombstones



allow four surfaces of vises to be worked on one rotary table pallet. A tombstone is a large, accurate, hardened block of metal that is bolted to the CNC pallet. The surface of the tombstone has holes to accommodate modular vises across all four faces on a pallet that can rotate to expose those faces to the machine spindle. New work holding fixtures are becoming available for five-axis machining



centers. These specialty vises allow the machine to work on surfaces that would normally be obscured when mounted in a traditional or tombstone vise setup. Jaws

Aluminum soft jaw shown holding five parts at a time in a CNC milling machine. 10

There are two main types of jaws on engineer's vises: hard and soft. Hard jaws are available with either a coarse gripping surface or are ground flat and smooth to increase accuracy. The latter relies on pressure for gripping, instead of a rough surface. An unskilled operator has the tendency to over-tighten jaws, leading to part deformation and error in the finished workpiece. Soft jaws are usually made from a soft metal (usually aluminum), plastic, or wood. They are used to either hold delicate workpieces or cut to hold specifically shaped workpieces. These specifically cut jaws are often used in place of fixtures and most commonly used in gang operations. They are also used for rapid change-over type set-ups since they can be easily engraved with the part number, the job number, or other information relevant to the job being run. Soft jaws are considered a consumable item, because they are discarded or recycled after multiple uses. Others 

hand vises



machine vises - drill vises (lie flat on a drill press bed). Vises of the same general form are used also on milling machines and grinding machines.



compound slide vises are more complex machine vises. They allow speed and precision in the placement of the work.



cross vises, which can be adjusted using lead screws in the X and Y axes; these are useful if many holes need to be drilled in the same workpiece using a drill press. Compare router table.



off-center vises



angle vises 11



sine vises, which use gauge blocks to set up a highly accurate angle



rotary vises



diemakers' vises



pin vises (for holding thin, long cylindrical objects by one end)



jewellers' vises and by contrast



leg vises, which are attached to a bench but also supported from the ground so as to be stable under the very heavy use imposed by a blacksmith's work.

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3. INTRODUCTION OF VICE AND CLAMPING: 3.1 General This project namely “Tilting Vice” is designed and fabricated by us is used for holding steel jobs for various purposes such as cutting, shaping, milling assembly works etc. It is mostly used by fitter and machinist. It has more advantages comparatively with other vices. It is light in construction, having more capacity to hold wooden jobs and other components. A vice is most common device used to hold work, for carrying out various operations, due to its quick loading and unloading capability. It may be fitted on a work-bench (table) or on a machine table. These are named accordingly as Bench Vice and Machine Vice respectively. For light duty work a small vice may also be held by hand. Such a vice is called Hand Vice. Provision is made in the design of each vice to adjust the distance between its jaws for accommodating different sized jobs. Usually a screwed pair is used for this purpose. Each vice has four main parts: 1. Fixed Jaw: It is usually integral with the vice body or base. 2. Movable Jaw: It slides on the ways of casting and is operated with a screw or spindle. 3. Screw: It gives the movable jaw the forward or backward movement and to do so it is rotated by a handle known as screw bar. 13

4. Casting: It constitutes the base of the vice and has ways for the movable bar. But in case of carpentry vice, it is mainly designed specially for wooden jobs to facilitate operations such as shaping or cutting off to length. CLAMPING: Clamping elements hold the work piece firmly engaged with the locating elements during operation. The clamping system should be strong enough to withstand forces developed during operation. At the same time, the clamping force should not dent or damage the work piece. Speed of operation, operator fatigue and strategic positioning are other important considerations for contriving a clamping system. 3.2 Principles of Clamping Position: Clamping should be positioned to direct the clamping force on a strong, supported part of the work piece. Clamping on unsupported part bends slender work pieces affects the accuracy of the operation. The clamping system should not obstruct the path of loading and unloading of the work piece. The clamps in the path of loading should be retractable or

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swinging type so that the clamps can be withdrawn or swung clear of the path of loading and unloading of the work piece. Clamps should not obstruct the path of the cutting tool. They should not get drilled, milled or welded during operation. Strength: The clamping system should be capable of holding the work piece security against the forces developed during operation. The clamping force should not dent or damage the work piece with excessive pressure. For clamping weak or fragile work pieces, the clamping force should be distributed over a wider area of the work piece. While clamping soft work pieces, clamps should be fitted with pads of softer materials, such as nylon or fibre to prevent damage and denting of the work piece. Productivity: Clamping time should be minimized by using hand knobs, tommy bars, knurled screws, hand wheels and handles so that the clamp can be tightened or loosened manually without using spanners, as a spanner further adds motions of picking, aligning, and laying it down. Operator Fatigue: 15

Operator fatigue should be taken into account. If a considerable number of clamps are to be tightened and loosened repeatedly, it is better to use pneumatic or hydraulic clamping which, in addition to reducing operator fatigue, also saves clamping time. Power clamping facilitates tightening or loosening of many clamps simultaneously.

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4. MAJOR COMPONENTS OF TILTING VICE This vice has nine parts which are assembled with the help of screw joints and weld. The parts are, 1. Base 2. Tilting base 3. Position pin 4. Fixed jaw 5. Movable jaw 6. Guide rodse 7. Screwed arrester 8. Screw rod 9. Handle Bolts and nuts are used for hinges and also used as a lock pin. 4.1 BASE It is the base of the all other parts. The base is welded with hinged edge post. The hinged edge post connects tilting base and it has vice arrangement. The base provides a support to the work piece griply and securely. This base is made up of Grade24 material (M.S), it is welded only by arc welding rod other details, and specifications are as follows, 4.2 TILING BASE:

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It is the base of the vice arrangement. The base is welded with hinged edge post. The hinged edge post connects tilting base and it has vice arrangement. The base provides a support to the work piece griply and securely. This base is made up of Grade24 material (M.S), it is welded only by arc welding rod other details, and specifications are as follows 4.3 POSITION PIN Position pin is used to fix the angle of vice. In our project we have fabricated one set of arrester, with the help of fasteners we can fix them. 4.4 FIXED JAW The fixed jaw is a single piece which is integral with crew rod and guide rod by means of bolts .these jaws use for clamping the work piece gripply and securely . The other detail and specifications are given below. SPECIFICATION Material

- Mild Steel

Weight

-

Operations -

1/2 kg Gas cutting, Shaping, Drilling, Tapping

4.5 MOVABLE JAW A moving jaw of three plates which are fixed to the screw rod using a bolt and nut. These jaws are also for clamping the work piece gripply and securely and specifications are given below. SPECIFICATION Material

- Mild Steel (PLATE) 18

Weight

-

Operations -

3/4 kg Cutting, Shaping, Drilling and Tapping

4.6. SCREW ROD This screwed rod consists of a “V-Thread’ of M 20 and pitch of 2.5 mm of course thread. At one end of the screwed rod , step is formed and a hole is drilled for inserting the handle rod and to fasten the movable jaw through the fixed jaw arrangement . The other details and specifications are given below. SPECIFICATION Material

- Mild Steel

Size

-

105 x Ø 20 mm

-

Weight -

Operations -

1 kg

Gas Cutting, Turning, Facing, Drilling, External Threading

4.7. HANDLE This is a lengthy cylindrical rod which is inserted to the head of the screwed rod. It is used for rotating the screw rod in clock wise or in antilock direction. In order to move the movable jaw holding arrangement forward or backward. The other details and specification are given below. SPECIFICATION Material

- Mild Steel (ROD) 19

Size

-

160 x Ø8mm

Weight

- 1/4 kg

Operations -

Turning, Facing.

4.8 Assembling of Parts To assemble the unit, the screw rod and guide rod are inserted into Fixed jaws and movable jaws through the holes which are already drilled. The handle head at the screw rod is inserted with the handle rod and the guide rods are arrested using M6 bolts. The other end of the screw rod and guide rods are arrested at the screw arrester using M6 bolts through the holes drilled by tapping process. The movable jaw is integrated with attached using M20 nut. When the handle rod is rotated which attached to the screwed rod the movable jaw moves slides forward over the rod and now the job is fixed between the jaws. When the handle is rotated in the opposite direction the jaw moves backward and tightens the job. The movement of the jaw is mainly depends on the rotation of the handle in the clockwise or anticlockwise direction.

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5.

DESIGN ASPECTS AND OPERATIONS

5.1. PROPERTIES OF MILD STEEL

PHYSICAL PROPERTY Density - 7680 kg/m3 Melting point -1427° c Thermal conductivity – 63 W/ Mk

CARBON CONTENT Low carbon (or) Mild steel – 0.15% to 0.45% carbon

MECHANICAL PROPERTY  Elasticity  Ductility  Toughness  Weld ability

5.2. OPERATIONS INVOLVED  Facing (flat surface) 21

 Drilling  Gas cutting (flat plate)  Shaping  Welding  Riveting  Thread cutting

FACING Machining the end of the work piece to produce flat surface is called facing. Due to this, the plate can get flat surface have done by facing operation. DRILLING Drilling is operation of producing cylindrical hole in the work piece. It is done by rotating the cutting edge of the cutter known as drill bit. In our project the drilling is done on the supporting post for inserting the hinged eye bolt and nut. GAS CUTTING Gas cutting is the process of cutting the metal in required shape and size by applying high pressure gas welding on the workpiece material. It is done on the base plate, equalizer plate, etc., SHAPING The process of shaping the job for required dimension using shaping machine is known as shaping. This is done in the MS plate to make equaliser. WELDING 22

The process of joining two similar or dissimilar metals is known as welding. It is done between the post and base. RIVETING The process of joining two plates.The holes in the plate is punched by a hand or riveting machine. It is done on the fixed and supporting arm. THREAD CUTTING Thread cutting is the operation of forming external thread of required diameter of rod by using a multipoint tool is called thread. This process is used in equaliser clamp to done on the rod, which is used for the movement of the clamp up and down. 6.3. DESIGN OF SCREW ROD SCREW DESIGN 0F M20 Size of the screw (Bolt) =M20 Pitch =2.5 mm (from pg –coarse series table1) For coarse thread dc =0.84 x d =0.84 x 20 Dc=16.8mm Stress area

=245mm2

Initial tension in bolt p 1=2860d =2860 x 20 =57200N But this p 1=3.14 x dc 2 x f1 /4 Tensile stress f1=p 1 x 4/ (3.14 x dc2) =57200 x4 (3.14 x 16.82) 23

F1 =258.04N/mm2 As the pin is double shear P1 =2 x 3.14 x dc2 2 x f1/4 F1= 57200 X 4 (2 X 3.14 X 1682) =128.71mm2 Shear stress As the pin is double shear P = 2 x 3.14 dc 2 x fs/4 Shear stress =Load/ area =57200 x 4/ (3.14 x 202) =91.03N /mm2

Therefore design is safe.

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7.

PROCESS AND PROCEDURE CHART

7.1. PROCESS CHART Part name

Operations

Machine used

The M.S plate of rough size is 1.Base

cut, drilled & shaped to finish size

2.Tilting base

3.Tilting arrester 4.Hinged Eye Bolt &Nut

Materials used

Gas cutting m/c Drilling m/c Mild steel

The M.S square of rough size is cut, drilled & shaped to

Shaping m/c

finish size

Drilling m/c

Mild steel

drilled at various distance

Drilling

Mild steel

The M.S rod is turned, faced,

Lathe

threaded & drilled to require

Drilling&

diameter.

Threading m/c

The M.S Rectangular plate

The M.S square of rough size 5.Fixed and is cut, drilled & shaped to movable jaw finish size

Mild steel

Shaping m/c Drilling m/c

Mild steel

For assembling of parts, welding has been done where ever necessary 25

7.2. DESIGN PROCEDURE CHART NEED OR AIM

YNTHESIS (MECHANISM)

ANALYSIS OF FORCES

MATERIAL SELECTION

DESIGN OF ELEMENTS (SIZE AND STRESSES)

MODIFICATION

DETAILED DRAWING

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PRODUCTION

7.3. MANUFACTURING PROCESS CHART

PRIMARY CUTTING PROCESS

MACHINING PROCESS

SURFACE FINISHING PROCESS

ASSEMBLING PROCESS

8. MANUFACTURING PROCESS 27

PRIMARY CUTTING PROCESS The processes used for preliminary cutting of the component are known as primary cutting process. The common operations involved in this process are gas cutting, sawing etc. MACHINING PROCESS The process used for giving final shape to the component according to the planned dimension is known as machining process. The common processes involved in this process are turning, planning, shaping, drilling, etc. SURFACE FINISHING PROCESS The process used to provide a good surface finish for the components are called as surface finishing process. The common operations used for this process are polishing, buffing, abrasive belt grinding, super finishing, etc. JOINING PROCESS The processes used to join the components are known as joining process. The common operations used for this process are welding, riveting, screw fastening, drilling etc.

8.1. GENERAL PROCEDURE OF DESIGN REGOGANISATION OF NEED First, make a complete statement of the problem, indicating the need, aim or purpose for which is to be designed. 28

SYNTHESIS (MECHANISM) Select the possible mechanism or group of mechanism which will give the desired motion. ANALYSIS OF FORCES Find the forces acting on the each member of the machine and energy transmitted by the each member. MATERIAL SELECTION Select the material best suited for each member of the machine. DESIGN OF ELEMENTS (SIZE AND STRESSES) Find the size of each member of the machine by considering the forces acting on the member and the permissible stress for the material used. It should be kept in the mind that each member should not deflect or deform then the permissible limit. MODIFICATION Modify the size of the member to agree with the past experience and judgment to facilitate manufacture. The modification may also be necessary by consideration of manufacturing to reduce overall cost. DETAILED DRAWING Draw the detailed drawing of each component of each assembly of the machine with complete specification for the manufacturing process suggested. PRODUCTION 29

The component, as per the drawing, is manufactured in the workshop. 9. COST ESTIMATION

S.NO

Name of the part

Weight in kg

Cost RS.

Base Plate

7

480

Tiliting plate

4

360

Hinged edge & Vice arrangement

2

145

Screw rod

1

250

Fixed jaw &Movable jaw

¾

100

1.

2.

3.

4.

5.

TOTAL = 1335.00

9.1. LABOUR COST Lathe, drilling, shaping, welding, riveting, turning, painting, surface grinding and gas cutting. Cost = Rs 1500.00 30

9.2. TOTAL COST Total cost

= material cost + Labour cost = 1425 + 1500 = 2225.00

Total cost for this project = Rs 2925.00

10. LINE DEIAGRAM

31

11.PHOTOGRAPHIC VIEW

32

12. CONCLUSION This report details with design of Tilting vice is attached with the Part drawings. The project carried out by us made an impressing task in the Manufacturing works. It is very useful for the fitters to clamp job of preferred size to perform the required operations to be carried out. This project has been 33

designed to perform the entire requirement task, which has also been provided.

REFERENCES

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1. Jig and fixture design by EDWARD.G.HOFFMAN. 2. Jigs and fixtures by P.H.JOSHI. 3. Work shop technology by R.S. KHURMI. 4. Engineering practice by R.K. NATARAJAN. 5. Machine tools (vol.2) by S.K. HAJRA CHOUDRY. 6. Design data by P.S.G. COLLEGE OF TECHNOLOGY

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