UNIVERSITY OF TECHNOLOGY, SYDNEYFACULTY OF ENGINEERING
MANUFACTURING ENGGINERING (48621)
MANUFACTURING REPORTHYDRAULIC GARAGE JACK
John La (12046280)
Semester 1, May 2015
Summary
Smaller vehicles can be manually lifted with ease, with the aid
of a hydraulic garage jack. Invented in 1851 by Richard Dudgeon,
this mechanical device serves for operations such as: tyre changes,
inspections or repairs underneath the vehicle.The jack has a shaft
whereby the user pushes to elevate the lifting pad, thereby,
lifting the object on top of the pad. The jack is able to lift such
a great amount of force, as the manufacturer has designed various
assembled parts to be working in conjunction to mechanically lift
an object with relatively low amount of effort.Industries are able
to mass produce these jacks by various manufacturing methods such
as: casting, pressing and machining each individual component, to
be assembled later to the completed hydraulic jack.In the interest
of the assembly of the jack, a sub assembly, the left-hand side
plate has several manufacturing operations involved to produce the
single piece. These details are explained within the report with
detailed diagrams depicting the order of operations.
Contents
Summary21.0 Introduction41.1 Material selection41.1.1 Advantages
of mild steel41.1.2 Disadvantages of mild steel41.2 Manufacturing
processes41.2.1 Pressing41.2.2 Cutting41.2.3 Fabrication41.2.4
Machining42.0 Instruction manual53.0 Conclusions and
recommendations94.0 Bibliography and Acknowledgements105.0
Appendix11
1.0 Introduction1.1 Material selectionThe material used for the
manufacture of the plate assembly is predominately mild steel,
which is iron with mixture of 0.30% - 0.59% carbon.1.1.1 Advantages
of mild steel Cost & availability: Being the common type of
iron metal, it can be readily used at relatively low cost.
Machinability: Mild steel is applicable for most processes making
it suitable material for its intended use. Properties: With the
addition of the carbon atoms to the molecular structure, it has a
perfect balance of ductility and strength with good wear
resistance.1.1.2 Disadvantages of mild steel Rust: If untreated,
the metal may rust and would degrade in quality.1.2 Manufacturing
processesFor the entire left-hand side plate assembly, the main
manufacturing processes done are pressing, cutting, casting,
fabrication and machining.1.2.1 PressingThis process involves
placing a flat sheet metal in stamping press where a tool and die
surface forms the sheet metal into a net desired shape.1.2.2
CuttingFor the precise hole cuts displayed in figure 1, principal
cutting processes are ideal. The most superior form being laser
cutting, where, an input from the computer directly send a laser to
make the cut on the specimen within a 0.1mm limit error.1.2.3
FabricationThe external pieces are aligned to the plate and ready
to be joined - as these are steel piece, they can be easily welded.
Gas metal arc welders operate at extreme temperatures with are high
enough to melt the separate work pieces together and also adds a
filler material to form a pool of molten material that solidifies
to form a strong joint (shown in figure 1)1.2.4 MachiningTowards
the end of the product, a final machining is always done with
computerised numeric controls to improve exterior quality and
precise dimensions. Additionally, threads (as shown in figure 2)
and other intricate designs may be done at this stage before the
final product is complete.
2.0 Instruction manual
Step 1: Producing the plate shape
A rectangular plate of mild steel (610x155x8) is fed through a
press machine with is set with the precise perimeter dimension* of
the plate outline. The press amounts with great force upon the
piece, leaving behind the shape of the plate ideal for the trolley
jack.
This is a cheaper alternative to laser cutting, as laser cutting
is unnecessary since the external features do not have any parts to
be assembled together to fit.
*dimensions given on diagram of plate
Step 2: Cutting holes
The plate is then set on a bed of a laser cutter. The operator
inputs the specific dimensions* for the laser cutter machine and
immediately, precise measurements and cuts are made on the plate
piece.
This method is extremely expensive; however, it is extremely
accurate. This allows for fixtures and jigs to be perfectly fitted
and may improve overall efficiency.
*dimensions given on diagram of plate
Step 3: Producing external pieces
Both the piece are created in simple ways: The shoulder plate is
pressed initially from a flat sheet to that desired shape from the
master press shape. The cyclinder is cut from a longer cyclindrical
piece.
Step 4: Fabricating the pieces
The plate, shoulder and spigot are all aligned to the
manufactures specifications* and gas arc welded. The extreme
temperatures of the bonds are fused together by the heat melting
the metals togethers and solidifying to a solid piece of the This
method of fabrication is very economical and reliable as it
requires relatively lower labour and material to for a single
piece. However, problems may persist if welded incorrectly such as;
distortions in the piece, careful maintenance. Furthermore, welded
joints are more brittle and therefore their fatigue strength is
less than the members joined.
*refer to owners manual
Step 5: Final machining
The final step to the complete sub assembly is machining.
Generally, with the advancement in technology, CNC machines are
preferably used.The operator, again, inputs the data for the
surface finish, drilling and taping for the final dimension. CNC
machines are highly accurate with a near zero percentage
error,however, the investment cost are high.
3.0 Conclusions and recommendations
To conclude the overall product for this sub assembly piece is
quite intensive, however, due to modern advancements in technology
in the manufacturing industries, these processes can be fully
automated to decrease the labour required to build the
components.Additionally, automated processes have made it possible
for the manufacturer to produce the hydraulic trolley jack to
economical proportions. Furthermore, processes such as the laser
cutting and computerised numerical control machining maybe
accurate, but, may appear unnecessary for the degree of perfection
within the trolley jack as these marginal error losses will not
affect the customer nor the device itself to any noticeable scale.
The manufacturer may consider using alternative cutting methods
such as oxy fuel or plasma cutting or more traditional and
efficient methods such as punching or pressing holes The
manufacturer may consider using a manual lathe final drilling as it
appears that the taping and drilling is relatively easy and quick
job rather than letting an expensive CNC machine doing to job.
Special paint may be coated on the separate sub-assemblies and
components to prevent rust from occur (since mild steel has the
potential to rust)
4.0 Bibliography and Acknowledgements
Hydraulic OEM Manual. (2015) Lecture notes. Retrieved 30.04.15
from UTS online:
https://online.uts.edu.au/webapps/portal/frameset.jspPlate cutting.
(2015) Lecture notes. Retrieved 30.40.15 from UTS online:
https://online.uts.edu.au/webapps/portal/frameset.jsp Solidworks
drawings obtained from Jaiman Williamson
5.0 AppendixFigure 1 - welded location
Figure 2 - threaded hole
Figure 3 - right hand side plate assemblyFigure 4 - shoulder
plate
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