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FIELD OF INVENTION
This invention relates to a single piece wheel for vehicle and a method for
manufacturing thereof. Said wheel is manufactured from a single piece of metal
sheet.
PRIOR ART
Conventionally, it is known to have been provided manufacturing process for
steel wheel, wherein the wheel is m.ade of two parts i.e. Rim and disc. The rim
is made by roll-forming process and the disc by press forming process. This is
followed by assembling of finished rim and disc part together by means of
welding process.
In addition the axle hub is made by die casting of Aluminium or Cast iron. The
wheel is fastened to the axle-hub by means of mounting bolt 85 nut assembly.
Reference may be made to fig. lA indicating standard wheel and Hub
assembly.
However, the disadvantages associated with the above are as follows:-
- Failure of the wheel at welded joint.
- Less strength of the wheel as it is made of two pieces.
- Problems caused by assembly of rim and disc are more.
OBJECTS OF THE INVENTION
The primary object of the present invention is to provide a single piece wheel
for vehicle and a method for manufacturing thereof which overcomes
disadvantages associated with the prior art.
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Another object of the present invention is to provide a single piece wheel for
vehicle and a method for manufacturing thereof which is efficient.
Further object of the present invention is to provide a single piece wheel for
vehicle and a method for manufacturing thereof which imparts more strength
to the wheel.
Yet another object of the present invention is to provide a single piece wheel for
vehicle and a method for manufacturing thereof which prevents failure of the
wheel due to the welding.
Yet another object of the present invention is to provide a single piece wheel
without mounting holes which is integrated with the ~axle hub manufactured
by flow-forming process or conventional press forming process', by welding or
any other joining process.
STATEMENT OF INVENTION
According to this invention, there is provided method for manufacturing single
piece wheel for vehicle comprising steps of:-
- shaping metal sheet,
- forming middle section of the disc with outer section to be formed into
rim, wherein thickness of material varies at required section,
- splitting the material to form two halves of rim, wherein thickness is
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maintained in such a way that it constitutes total volume of rim, I
- transformation of two halves into the required shape of the rim,
- integration of wheel with axle hub.
Further, according to this invention there is provided a single piece wheel for
vehicle comprising of disc integrally provided with rim wherein axle hub is
integrated with the wheel.
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BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Further objects and advantages of this invention will be more apparent from
the ensuing description when read in conjunction with the accompanying
drawings and wherein:
Fig. 1: shows: flat metallic sheet for wheel of the present invention.
Fig. 2 shows: metallic section for disc and rim.
Fig. 3 shows: splitting of rim into two halves.
Fig. 4 shows: shape of the rim.
Fig. lA shows: conventional steel wheel and hub assembly.
Fig. 2A shows: a single-piece steel wheel according to present invention.
Fig. 3A shows: a single-piece steel wheel and flow formed hub assembly
according to present invention.
DETAILED DESCRIPTION OF THE INVENTION WITH REFERENCE TO THE
ACCOMPANYING DRAWINGS
The present invention is directed to a single piece wheel for vehicle and a
method for manufacturing thereof. Said method comprising of the following
steps:
- Taking a flat sheet of required material (fig. 1) considering the required
thickness for both rim and disc. i.e. the total mass of the initial blank
comprises the combined masses of rim and disc since both are to be
formed from this single blank unlike other wheels where rim and disc are
two different parts.
The shape of the blank is made round after trimming from the input
sheet, since this outline forms the rim edge.
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- Forming middle section of the disc leaving the outer section to be formed
into rim (fig. 2). The thickness of material varies at required section.
- The input shape thus obtained is used in a flow forming operation so as
to split the material to form the two halves of rim (as shown in fig. 3). The
thickness in this area is maintained in such a way that it constitutes the
total volume of the rim.
- The two halves thus split are converted into the required shape of the rim
(fig. 4) by means of a rolling or flow forming operation.
Thus, the invention of the proposed application does not involve welding unlike
conventional wheel. Hence, the strength of the wheel is more as compared to
wheels with welding because the rim and disc constitute a single consolidated
piece. 1
Now, reference may be made to fig. 2A showing single-piece wheel assembly.
Manufacturing process for the single piece wheel is as foUows:-
Blanking -^ Pre-form —» Rim Spinning_l —» Rim Spinning_2
or
Blanking -^ Flowforming —>• Rim Spinning_l -^ Rim Spinning_2
The above process are given as example without restricting scope of the
invention to the same.
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Flow Forming in Passenger Car Rim
- To reduce the wheel rim weight without effecting the functional
requirements.
- Through introduction of variable thickness rim design, by identifying the
areas where there is comparative lesser influence of Radial and Impact
loads.
The present invention involves integration of a single piece wheel (flow formed
or non-flow formed) with the axle hub by means of welding.
The axle hubs are conventionally made by casting process. In the present
invention the hub is changed in a way to suit forming process such that the
part can be made from steel. The forming process can be either press-forming
or flow forming.
The material of the wheel can be for example Steel, Alumninium, Stainless
Steel. Thus, other materials/process readily apparent to person skilled in the
art are understood to be within the scope of the invention.
Reference may be made to Fig.3A for the single-piece steel wheel and flow
formed hub assembly.
Advantages
r* Rim 86 Disc made from single input blank.
^ No welded joints
^ Higher Strength
^ Design compatible with standard Valves.
^ Better Flatness control
^ Better Runout control
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And additional advantages of Single-piece wheel with flowformed hub are,
Standard Aluminium hub substituted with steel hub
^ Flowforming process of steel hub reduces weight
>^ Elimination of mounting bolts
A" Reduction in cost of wheel 85 hub assembly
It is to be noted that the present invention is susceptible to modifications,
adaptations and changes by those skilled in the art. Such variant embodiments
employing the concepts and features of this invention are intended to be within
the scope of the present invention, which is further set forth under the
following claims:
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WE CLAIM;
1. Method for manufacturing single piece wheel for vehicle comprising steps
of:-
- shaping metal sheet,
- forming middle section of the disc with outer section to be formed into
rim, wherein thickness of material varies at required section,
- splitting the material to form two halves of rim, wherein thickness is
maintained in such a way that it constitutes total volume of rim,
- transformation of two halves into the required shape of the rim,
- integration of wheel with axle hub.
2. Method for manufacturing single piece wheel for vehicle as claimed in
claim 1, wherein the flat metal sheet is made of material such as
stainless steel, aluminium steel. I
3. Method for manufacturing single piece wheel for vehicle as claimed in
claim 1 or 2, wherein the mass of sheet comprises combined masses of
rim and disc.
4. Method for manufacturing single piece wheel for vehicle as claimed in
any of the preceding claims, wherein the metal sheet is shaped round by
trimming from the input sheet to form the rim edge.
5. Method for manufacturing single piece wheel for vehicle as claimed in
any of the preceding claims, wherein the splitting is carried out by flow
forming operation.
' 6. Method for manufacturing single piece wheel for vehicle as claimed in
any of the preceding claims, wherein said transformation is carried out
by means of rolling or flow forming.
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7. Method for manufacturing single piece wheel for vehicle as claimed in
any of the preceding claims, wherein the hub is manufactured by
forming process i.e. press forming or flow forming.
8. A single piece wheel for vehicle comprising of disc integrally provided
with rim wherein a single piece wheel is with or without mounting holes
and is integrated with the 'axle hub manufactured by flow-forming
process or conventional press forming process', by welding or any other
joining process.
9. A single piece wheel for vehicle and a method for manufacturing thereof
as claimed in any of the preceding claims, is associated with the
advantageous features such as herein described.
I 10. A single piece wheel for vehicle and a method for manufacturing thereof
substantially as herein described with reference to the accompanying
drawings.
Dated this 19* day of August, \ j 2013
(SOMA RANI MlSff^!)
OFL.S.DAVAR85CO.,
APPLICANT'S AGENT