Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
Body and container for transport of construction sand and gravel mining, and
fabricating method
Field of the Invention
The present inventions relates to hoppers and methods for constructing
hoppers.
These hoppers may be applied to mining trucks and aggregate trucks in general.
The
invention also relates to train freight cars and to methods of constructing
train freight cars.
Background to the Invention
Hoppers for mining trucks are known, as are aggregate trucks in general, and
train
freight cars of different designs and shapes that are used to transport
materials or mineral
ore of differing granulometries, particle sizes and densities, which causes
the volume or
tonnage to differ depending of the latter parameter as regards an identical
volume.
Hoppers are generally made from structural steel and, in some cases, anti-
abrasive steels,
depending on the application and loading system. This latter point differs
from each site,
giving a better or worse condition with respect to the loading of the
material. Sometime the
material is loaded through a chute, which is a rather gradual and controlled
loading. Other
times the loading is an impact loading, such as for example in the case of a
front loader
wherein the load projects over by the sides of the hopper and the load drops
instantly on
the loading area or on a side of the hopper. Sometimes the operator loses
sight of the
equipment or load. In all loading cases, the welds that are used to join sides
and floor or
front and floor become seriously damaged by various means.
It is advantageous, for all of the aforementioned conditions, to have stronger
hoppers given current conditions and trends in the mining industry, which
prefers larger
equipment and greater loading capacity, with greater equipment maintenance
availability.
To achieve this effect, larger and stronger hoppers are required. A larger
number of
structures would facilitate making the hoppers stronger and/or thicker in
order to absorb
impacts, in addition to increasing availability as a result of the wearing of
the plates that
are in contact with the material and aggregate's sliding upon emptying.
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Known materials and methods of construction make the hopper and components
sturdier, increasing its own weight along with a consequent decrease in the
material
transported, depleting from the equipment (trucks or freight cars) loading
capacity. On the
other hand, if a lighter hopper is made, sacrificing the thickness and
materials of its
structure, the frequency of its maintenance or replacements will have to be
increased to
cope with the decreased equipment availability due to frequent maintenance.
Users
seek a balance of a hopper being able to resist loads and impacts and
abrasion, and, in
turn, light for its availability for corrective maintenance to be greater.
Summary of the Invention
In accordance with a broad aspect of the present invention there is provided a
hopper suitable for use on a mining truck, the hopper comprising selected
regions
strengthened by folded elements.
In accordance with a first aspect of the present invention there is provided a
mining truck hopper, comprising:
a floor having a front and a rear;
first and second sidewalls extending upwardly from the floor, the first and
second
sidewalls having outside surfaces;
a front wall extending upwardly from the front of the floor and extending
between
the first and second sidewalls;
a shield wall extending forwardly from the front wall in a direction away from
the
rear of the floor;
the floor and the first and second sidewalls are joined by folds and there are
no
welds between the floor and the first and second sidewalls;
the shield wall includes a shield fold that extends transversely to the first
and
second sidewalls, and the shield fold is located forward of the front wall and
rearward of
a front end of the shield wall;
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the front wall includes a plurality of folds that extend transversely to the
first and
second sidewalls and parallel to the shield fold;
the floor, the first and second sidewalls, the front wall, and the shield wall
are
made of steel; and
the first and second sidewalls are supported by two folded beams on the
outside
surfaces of the first and second sidewalls.
In one example, the steel may have a hardness of at least 200 Brinell.
In one example, the steel may have a hardness of at least 500 Brinell.
In one example, the steel may have a hardness between 200-500 Brinell.
In one example, the steel may have a strength of at least 300 MPa.
In one example, the steel may have a strength of at least 700 MPa.
In one example, the steel may have a strength of between 300-700 MPa.
In one example, the steel may be A514 steel.
In one example, the steel may have a thickness of at least 6 mm. The steel may
have a thickness of at least 25 mm. The steel may have a thickness of between
6-25
mm.
In one example, the steel may be one or a combination of anti-abrasive steel
that
is denominated or classified in accordance with its hardness, being from 200
to 500
Brinell, or over, at the zone that comes in contact with the material to be
loaded, or as
required. In one example, the resistance of the steel may be within a 300 Mpa
to 700
Mpa range, or over.
In one example, the folds in the front wall may extend from adjacent to the
floor,
and may extend from the first sidewall to the second sidewall.
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In one example, the shield fold may extend from one side of the shield wall to
an
opposite side of the shield wall.
In one example, the floor may be sloped downwardly with the rear of the floor
disposed higher than the front; the front wall may be sloped in a forward
direction with
an upper portion of the front wall spaced further from the rear of the floor
than a lower
portion of the front wall.
In accordance with a second aspect of the present invention there is provided
a
hopper structure configured to transport mining material, comprising:
a floor having a front and rear;
first and second sidewalls extending upwardly from the floor, the first and
second
sidewalls having outside surfaces;
a front wall extending upwardly from the front of the floor and extending
between
the first and second sidewalls;
a shield wall extending forwardly from the front wall in a direction away from
the
rear of the floor;
the floor and the first and second sidewalls are joined by folds and there are
no
welds between the floor and the first and second sidewalls;
the shield wall includes a shield fold that extends transversely to the first
and
second sidewalls, and the shield fold is located forward of the front wall and
rearward of
a front end of the shield wall;
the front wall includes a plurality of folds that extend transversely to the
first and
second sidewalls and parallel to the shield fold; the floor, the first and
second sidewalls,
the front wall, and the shield wall are made of steel having a hardness of at
least 200
Brinell, a strength of at least 300 MPa, and a thickness of at least 6 mm; and
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the first and second sidewalls are supported by two folded beams on the
outside
surfaces of the first and second sidewalls.
In one example, the steel may be A514 steel.
In one example, the folds in the front wall may extend from adjacent to the
floor,
and may extend from the first sidewall to the second sidewall.
In one example, the shield fold may extend from one side of the shield wall to
an
opposite side of the shield wall.
In one example, the floor may be sloped downwardly with the rear of the floor
disposed higher than the front; the front wall may be sloped in a forward
direction with
an upper portion of the front wall spaced further from the rear of the floor
than a lower
portion of the front wall.
As described herein, embodiments of the present invention are based on the
use of state of the art or cutting edge technological elements in order to
fulfil the
objectives required by current market, achieving resistance to greater loading
capacity
without increasing its weight from structuring the unit or lengthen its useful
life due to
floor abrasion to meet availability as required by the customer.
In order to facilitate the resistance and availability requirements there
presently
exist steels having greater tensile strength, from 300 MPa to 700 MPa tensile
strength,
depending on the type and origin. Embodiments of the present invention utilise
steels
having better mechanical properties, a structure being able to equal or
greater tensile
strength without having to increase the thickness of the materials, since
their densities do
not vary much, in addition to making a design with computer design methods and
tools
currently available in order to simplify the structure, said structure being
virtually analyzed
fast and safely, which allows the making of steel folds at critical areas of
the hopper which
makes it stronger. At the same time, in order for these folds to be made, more
powerful
and high-precision equipment is required, which forces us to use large folding-
capacity
technology having CNC's (Computer Numerical Controls) given the size of the
precision
pieces and the steels also require more power to fold due to their special
properties.
CA 2714733 2017-09-06
In one embodiment, in order to prevent abrasion wear, abrasion-resistant
steels
having hardness indices spanning from current 200 Brinell to at least 450
Brinell (for
example, 500 Brinell), being able to considerably increase the useful life
against abrasion,
but the tensile strength of which rises from about 800 Mpa to at least 1,400
Mpa are
provided, which requires, moreover, the use of more robust equipment than
traditionally,
as was stated above. This allows to provide a highly strong, highly available
product for
production, but having a low structural weight, thus allowing to transport
larger loads and
reduce the cost of fuel consumption, which, in large pieces of equipment, is a
factor of
considerable relevance.
Traditional manufacture of hoppers is based on very heavy structures having
standards beams. In some cases, special materials are used depending on the
design,
but they do not comply with the abovementioned objectives. As regards light
hoppers,
their weight is smaller in order not to reduce the truck's capacity, but have
a shorter
useful life due to shocks and/or abrasion, which forces the equipment to
remain idle for
more frequent maintenance.
As for applications of anti-abrasive steels, they are applied in their natural
state as
unfolded plates as a result of their high strength properties, and because
making them with
standard methods is very difficult.
Embodiments of the present invention include special handling when applying
the
materials, in particular the cuffing-edge steels described herein, since the
challenges
faced to fold the design, including the sizes of the components, and the folds
that are
located at particular and strategic places. These challenges are alleviated by
the
assistance of computer simulation tools so that the precise support for the
hopper may be
facilitated. This is facilitated by supplementing and adapting software
related to 3D
studies, together with finite element analysis upon developing each part, and
later the
general analysis of the assembly, simulating different typical working
conditions on
upward and downward slope, side inclinations, etc.
One embodiment of the present invention provides floor elements comprising
floor
folds with anti-abrasive side, the folding that reduces or eliminates welding
at joints and
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floor, which improves mechanical resistance and alleviates stress arising from
heat
concentration upon welding.
In one embodiment, at the sides, reinforcement on several beams is simplified
by
two larger joining beams that keep the structure substantially rigid.
In one embodiment, at the front of the hopper, where the impact of the load
and of
the loading cone joins the cabin, this plate is folded and its form and size
reinforces its
structure by replacing outer reinforcement beams, decreasing the weight of the
hopper
and holding a greater additional load of material. The direction of the
folding or of the
folds may be transverse or longitudinal, or both, and it will depend on the
design or load
conditions.
Some features of the hopper shield are set out in the paragraph below. This
element, in general, is not analyzed in detail, only as regards safety
considerations
related to the protection the truck cabin against excesses or spills hood of
load from the
cone. In this case, in addition, the protective element was folded in order to
have the
necessary resistance. In this case the fold is transverse, but it may take a
longitudinal
folding condition, or both, thus eliminating several reinforcement beams and
especially
being limited to the load cone with a retaining effect so that the material
does not pass
that point towards the truck's front area, thus changing the load's center of
gravity, varying
the distribution of the load between truck axles, thus affecting tire wear,
among other
effects on the truck's structure.
In addition, using fewer beams and simplifying the design by the folded large-
piece
system makes its compact structure contain stress concentration points,
helping its
performance as a structural assembly subjected to cyclical stress, minimizing
the
likelihood of specific failures.
The supplement of each one of the studies on each hopper, both in the system
and in the database, allows us to adapt the design to the needs of each
customer as for
manufacture and design, being able to make improvements in accordance with
operational conditions at each site, that is, the density of the material is
low, with respect
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to the one considered in the initial study, the hopper's volume may be
increased and/or
the thickness of the materials may be reduced, that is, lower the safety
factors where
indicated and allowed by the analysis without affecting a quality and reliable
product. The
direction and number of the folds in each part of the hopper or of the freight
car is
determined according to the structure, load parameters and study of the
components'
finite elements.
Brief Description of the Drawings
Embodiments of the present invention will be hereinafter described, for the
purposes of clarity and increasing understanding, with reference to the
following
drawings, and in those drawings:
Figure 1 shows an isometric view of a hopper in accordance with an embodiment
of the present invention, illustrating a shield fold for increasing strength
of the shield and
for resisting movement of transported material towards the equipment's front
area;
Figure 2 shows a rear view of the hopper of Figure 1, illustrating the joining
folds
between the equipment's floor and side; and
Figure 3 shows a side elevation view of the hopper of Figure 1, illustrating
the
joining of two folded beams, in form and size, which, in their layout, replace
several
beams having the same purpose.
Detailed Description
A preferred embodiment of the present invention provides a hopper shown in
Figure 1, which incorporates a simplified number of pieces to form a heavy
(from 100 to
400 ton) mining truck hopper. The hopper design shown in the Figure
advantageously
incorporates strategic simplifications in its manufacture, a reduced number of
components
and the application of steels (e.g., A541 steel), providing a hopper having
greater
resistance to impacts as a result of its design containing strategic folds,
greater abrasion
resistance from the use of the steels. It is also lighter because its design
eliminates
structural beams, making it an advantageous hopper for facilitating at least
some of the
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objectives herein described, achieving a balance between the increased
strength and
reduced weight of the hopper. Advantageously, this provides several
advantages:
1. lower costs as a result of its longer useful life;
2. improved shield, which allows the loading cone not to move towards the
cabin, keeping load center, deceasing tire wear and, more importantly,
increasing the truck operator's safety.
Another preferred embodiment may be applied to small tonnage train and truck
cars, because the design is fully adaptable to any size and shape as desired,
since the
preferred designs are computer analyzed, proving the effectiveness of each one
of the
preferred embodiments.
As is shown in Figure 1, zone A, being a shield wall 10 having a shield fold
12 for
resisting and retaining the material moving towards the equipment's front zone
is
identified. The shield fold 12 extends from one side of the shield wall 10 to
the opposite
side of the shield wall 10 transverse to the sidewalls, and the shield fold 12
is located
forward of the front wall and rearward of a front end of the shield wall.
Further shown in Figure 1, Zone B, a folded front piece 14, improves body
resistance and eliminates structural pieces, prevents this zone from buckling
due to its
folded form, namely a plurality of folds 16. The direction of the folding may
be
transverse as shown in the figure, and/or may be longitudinal, as required by
the
loading to be applied.
Zones C and D, in Figure 2, show joining folds between the equipment's floor
18
and side walls 20. As for the fold, it may be folded along with the load flow
if required by
the study.
In Figure 3, point E shows the joining of two folded beams 22, 24 in shape and
size that, in their layout, replace several beams fulfilling the same purpose,
structuring
the assembly's side portion. The side plates may be folded vertically or in
the direction
of the flow, as required.
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