Download - JIG AND FIXTURES
SANDWICH JIG DRILL MANUFACTURING
Minor Project Report
Bachelor of Technology In
Mechanical Engineering
Submitted by: Supervisor:Osaama Ullah Khan Mr. Ram dayal Asst. LecturerMechanical Batch B
DEPARTMENT OF Mechanical ENGINEERINGMewar University,
NH - 79 Gangrar,Chittorgarh (Rajasthan) – 312901, India
ACKNOWLEDGEMENT
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I am very pleased to express my deep sense of gratitude to my esteem guide
“Mr. Ram dayal” for his valuable training, encouragement and facilities
provided during the project Work.
There were umpteen moments when I learned heavily from him. It is the fact,
without his construction and simulating criticism arduous but invaluable advice
sought time to time, masterly guidance deep personal interest and attention, this
work would not have seen the down of the day and could never have attend the
present stage. I am also heartily thanks to Mr. Ashok Gadiya(Honorable,
Chancellor), Mr. Harish Gurnani(Director, training and placement), Mr. D.K
Sharma (HOD, Department of MECH) and all faculty members for their co-
operation .I extend my sincere thanks to my friends who were there with me
directly or indirectly during the Work.
PLACE: Chittorgarh B.Tech, IVthyear
DATE : 21/11/2013 Mechanical Engineering
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Abstract
Jig and Fixtures setup is used to reduce the work load within the Company.The
jigs and fixtures are the economical ways to produce a component in mass. So
jigs and fixtures are used and serve as one of the most important facility of
mass production system. These are special work holding and tool guiding
device. Quality of the performance of a process largely influenced by the
quality of jigs and fixtures used for this purpose. What makes a fixture unique
is that each one is built to fit a particular part or shape. The main purpose of a
fixture is to locate and in the cases hold a workpiece during an operation. A jig
differs from a fixture in the sense that it guides the tool to its correct position
or towards its correct movement during an operation in addition to locating
and supporting the workpiece.
.
CONTENTS
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Topic Page No.
ACKNOWLEDGEMENTS 03
ABSTRACT 04
CHAPTER:-1 INTRODUCTION
1.1 Definition 06
1.2 Purpose and Advantage 07
CHAPTER:-2 TYPES OF JIGS
2.1 Table. 08
2.2 Angle. 09
2.3 Plate. 10
2.4 Sandwich. 11
CHAPTER : - 3 MATERIAL USED & DIMENTIONS 12
CHAPTER:- 4 CONCLUSION
4.1 Conclusion of project 13
4.2 References 13
List of Figure
S.No. Figure no. Page No
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01 2.1.Table Jig 09
02 2.2. Angle Jig 10
03 2.3. Plate Jig 11
04 2.4.Sandwich jig 11
05 2.5. Load Curve 12
CHAPTER:-1
INTRODUCTION
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1.1Definition
The jigs and fixtures are the economical ways to produce a component in mass. So jigs and fixtures are used and serve as one of the most important facility of mass production system. These are special work holding and tool guiding device. Quality of the performance of a process largely influenced by the quality of jigs and fixtures used for this purpose. What makes a fixture unique is that each one is built to fit a particular part or shape. The main purpose of a fixture is to locate and in the cases hold a workpiece during an operation. A jig differs from a fixture in the sense that it guides the tool to its correct position or towards its correct movement during an operation in addition to locating and supporting the workpiece.
An example of jig is when a key is duplicated; the original key is used as base for the path reader which guides the movement of tool to make its duplicate key. The path reader of a CWC machine here works as a jig and the original is called template. Sometimes the template and jig both are the name of same part of a manufacturing system..
1.2 .PURPOSE AND ADVANTAGES OF JIGS AND FIXTURES
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(a) It reduces or sometimes eliminates the efforts of marking, measuring and setting of workpiece on a machine and maintains the accuracy of performance.
(b) The workpiece and tool are relatively located at their exact positions before the operation automatically within negligible time. So it reduces product cycle time.
(c) Variability of dimension in mass production is very low so manufacturing processes supported by use of jigs and fixtures maintain a consistent quality.
(d) Due to low variability in dimension assembly operation becomes easy, low rejection due to les defective production is observed.
(e) It reduces the production cycle time so increases production capacity. Simultaneously working by more than one tool on the same workpiece is possible.
(f) The operating conditions like speed, feed rate and depth of cut can be set to higher values due to rigidity of clamping of workpiece by jigs and fixtures.
(g) Operators working becomes comfortable as his efforts in setting the workpiece can be eliminated.
(h) Semi-skilled operators can be assigned the work so it saves the cost of manpower also.
(i) There is no need to examine the quality of produce provided that quality of employed jigs and fixtures is ensured.
2. Various types of Jigs :-
1. Table.
2. Angle (Modified and Normal)..
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3. Plate.
4. Sandwich.
2.1. Table jig : -
Table jig is plain plate jig with legs.
Main purpose is holding irregular or non-symmetrical work pieces that
cannot be held in other plate jig forms.
The part is referenced by the surface being machined rather than the
opposite side.
Table jigs can accommodate almost any shape work piece.
Limitations are the size of the part and availability of clamping surfaces.
Sample of a Table Jig
The part is clamped between jig plate and the clamping device
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Fig.2.1
2.2 Angle jig : -
Angle plate jigs are used to hold parts that are machined at right
angles to their mounting locators.
A variation is the modified angle plate jig, which is used for machining
angles other than 90 degrees.
Allow the drill to complete the hole .
avoid drilling the relieved portion of the locator.
Sample of Angle Jigs
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Fig.2.2
2.3 Plate Jigs : -
Plate jigs are basically modified or improve template jigs.
While performing the same locating function as template, they also
incorporate a mean of securing the part.
This added feature, clamping, is what allow plate jigs to locate part
with a high degree of accuracy and repeatability.
Plate jigs are actually a family of jigs rather than a single type of to
Sample of Plate Jigs
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Fig. 2.3
It is moveable on big plate type objects as a guide
2.4 Sandwich jigs
the sandwich jig is almost identical to a plain plate jigs.
the only difference is the backup plate found on the sandwich jigs.
this back up plate allows the jigs to hold very thin part that could
bend or distort under tool pressure.
another use of a sandwich jig is as a combination jig.
Sample of Sandwich Jig
Fig.2.4
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3. MATERIAL USED & DIMENSIONS : -
Mild steel plates are used each having dimensions as follows : -
Plates:-
Length = 16cm
Breath = 4.5cm
No. of Locating Pin Holes = 4 holes each of dia 6mm for drilling
operation.
= 4 holes each of dia 6mm for locating pins.
4 for nut and bolts for holding the job having dia. Of 6mm.
Load cuve : - stress-strain graph for mild steel plates.
Fig. 2.5
4 .1 CONCLUSION: -
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Open Jigs are convenient and simple.
Cheap to produce which is good for economical reasons.
Suitable for home and industrial.
Cheap and best for simple drilling operations.
Drilling upto 10 mm in dia. can be done on job on the sandwich jig
drill.
4.2 REFERENCES: -
www.wikipidea.com .
http://en.wikipedia.org/wiki/Stress%E2%80%93strain_curve .
P.N.Rao M.T-2.
www.slideshare.com .
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