Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
1 334834
- The present invention relates to a manganese
steel corner element with joining holes on its three outer
sides.
Different types of containers which are
categorized by the ISO standards according to size (10 to
40 feet length) and load capacity (10, 20, 24 and 30 Mp)
are used for transporting piece goods, bulk goods, liquids,
etc.
The corner elements are placed at the 8 corners
of containers, facilitating their being elevated or joined
together or joined to the transporting vehicle either
horizontally or vertically. The corner elements are
connected by vertical and horizontal holders made of rolled
plates or profile forms. In addition to their movability,
elevating and fastening, it is important that containers
can be stacked on each other.
According to the traditional technical methods
applied so far, corner elements have been steel-cast by
container manufacturers, and the finished castings are
usually welded manually or on a low mechanization level to
the vertical and horizontal holders. Checking the welds is
awkward and not entirely safe. Among the possible failures
of containers, beside the breakage of corner elements, seam
rips or breaks have been quite common owing to defective
welding. When it comes to repairs (e.g. a broken corner
element needing to be replaced) the maintenance of the
original sizes and clearances is difficult and requires
much time and energy. Besides, users are forced to
withdraw the defective containers from operation for a long
time.
In the October, 1985 issue of the scientific
review Cargo Systems P. Hewitt reports on tests concerning
cast corners, carried out by Sea Containers in cooperation
with the research laboratory Iron and Steel Co. and the
Trade Association Sheffield company. The examinations
included different measurements and tests on cast corners
- 1- .~
1 3348~
- made in different countries all over the world. The
results as regards Charpy's impact energy at low
temperature are set out in the following table.
Impact energy Temperature
(average of 3
Manufacturer measurements) C
A 4.0 J -40
B 7.5 J -40
C 14.5 J -40
D 10.5 J -40
A suitable material for manufacturing corner
elements must meet the specification of IS0 1496/1 and/or
LR 1984, where the required values at -40C, at a "V" slot
and with Charpy's method are the following:
on a 10 x 10 mm test bar min. 34 J
10 x 7.5 mm test bar min. 28 J
10 x 5 mm test bar min. 23 J
The table shows that these requirements are met
by none of the manufacturers listed. This led to the
perception that one of the defects of cast corners
manufactured with the present state of technical knowledge
is the unsatisfactory value of impact energy at low
temperatures.
A British company called Blair has recently
developed a corner element that after a single normalizing
heat-treatment and at -50C provides an impact energy value
of KVmjn= 21 J. However, it is not at low temperatures that
most breakages of corner element occur. In fact, according
to data supplied by large railway companies (such as the
West German DB, the French SNCF or the British BR) damage
to corner elements or seam rips of their holders takes
place in the positive temperature range owing to rough
-
- 3 ~ 1 33~ 8~ ~
elements must meet the specification of IS0 1496/1
and/or LR 1984, where the required values at -40 C, at
a "V" slot and with Charpy's method are the following:
on a 10 x 10 mm test bar min. 34 J
10 x 7.5 mm test bar min. 28 J
10 x 5 mm test bar min. 23 J
The table shows that these requirements are met by
neither of the manufacturers listed. This led to the
perception that one of the defects of cast corners
manufactured at the present state of technical knowledge
is the unsatisfactory value of impact energy at low
temperatures.
A British company called Blair has recently
developed a corner element that after a single normaliz-
ing heat-treatment and at -50 C amounts to the impact
energy value of KVmin= 21 J. However, it is not at low
temperatures that most breakages of corner element occur.
In fact, according to data supplied by big railway
companies (such as the West German DB, the French SNCF
or the British BR) the damage of corner elements or the
seam rips of their holders take place in the positive
temperature range owing to rough handling and reloading
as well as in the course of shunting and marshalling of
railway wagons.
Owing to the material composition of steel
castings and the additional dynamic stress due to rough
handling, their mechanical qualities get poorer in the
negative temperature range. All these result in cracks
1 334834
due to the casting technology corner elements
weigh too much;
the 8 corner elements required for each container
can be manufactured only in four patterns, shaped and cast
separately.
It follows from the foregoing that to manufacture
the corner elements in accordance with the specifications
is not easy.
It is an object of the invention to eliminate the
disadvantages of the known method and to provide a new type
of corner element that
is suitable for serial production regarding
material, structure and technology,
is economical of energy and does not require
repeated heat treatment,
is suitable for being stacked, and
has an impact energy at low temperature in
accordance with the specifications.
Accordingly, the invention provides a corner
element for a container, made of manganese steel, with
joining holes on its three outer sides, characterized by
being made of a steel-plate having a Mn:C ratio of 8 to 12,
a total phosphorus plus sulphur (P+S) content of a maximum
of 0.04 percent by mass and a carbon content of a maximum
of 0.2 percent by mass.
The material of steel-plates of this composition
is homogeneous, it has pliable edges (Rmjn= a/2 mm, wherein
"a" stands for the plate thickness) and its impact energy
value (KVmin) at -40C amounts to 21 J. The wall thickness
of the corner elements made of such material will be
smaller than that of a casting, thus it is advisable to
arrange distance inserts on the inner sides of the joining
holes, thereby ensuring proper connection with fastening
elements.
The steel-plate that serves as the basic material
of the corner element according to the invention is of
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1 334834
- homogeneous granular structure even in a direction
perpendicular to the direction of rolling, and is suitable
for applying cold-working technology. Its elongation value
(~) is over 22 percent and its edges are quite pliable.
The sizes and degrees of tolerance of the corner
elements made of such a material meet even the strictest
specifications (e.g. ISO 1161). The mass of these corner
elements is at least 10 percent less than that of their
steel-cast counterparts and its dispersion is 2 percent
less than the rated value. They require hardly any
remachining and can be replaced within the container simply
and quickly. The individual stages of their manufacture
can be mechanized to a high degree, so robotization is also
applicable, enabling high precision and reproducibility of
production.
The production of the corner element can be based
on the cold-working technology which is simpler and of low
energy consumption. The plates cut (pressed) are bent and
assembled as cold. The welding of the elements can be
carried out by robots horizontally, by simple geometrical
tracing. The root of weld is fixed and welding is
reproducible with high precision. The finished product
does not require any further heat-treatment and the
technology of its replacement is much simpler.
Two embodiments of assembly of the corner element
according to the invention are shown in Figures 1 to 7. In
the second embodiment the six sides of the corner element
are formed from two trilateral shell elements the sides of
which are joined along three edges and together form one
common peak, while the sides of the shell elements of the
first embodiment are joined along two edges, and the shell
elements are generally U-shaped.
In the drawings:
Figure 1 shows the top and side views of
embodiment 2 of the corner element and its section along
line D-E;
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1 334834
Figure 2 represents a blank of the shell element
"A" of embodiment 2;
Figure 3 shows a blank of the shell element "B"
of embodiment 2;
5Figure 4 shows shell elements "A" and "B" of
embodiment 2 together with their distance inserts;
Figure 5 shows the distance inserts C1 and C2 of
embodiment 2 and a blank from which inserts C3 may be cut;
Figure 6 represents the corner element assembled
from shell elements "A" and "B" and the distance inserts of
version l; and
Figure 7 shows the exploded view of version 2 of
the corner element according to the invention, wherein "A"
and "B" are the two shell elements, C1, C2 and C4 are the
distance inserts and the lines h-h represent the bending
edges.
The corner elements arranged in the upper and
lower planes of the container differ only in respect of the
sizes of the holes on their shorter sides; therefore, the
shell elements "A" are manufactured with two different
holes. The shell elements "B" are identical in the upper
and lower rows and are shaped in such a way that they form
the corner element together with their counterparts "A".
The shell element "A" with a slight modification
can be considered a finished product as it can serve as the
corner element of tank containers.
The size and tolerance values of the corner
element represented in Figures 1 to 7 meet the 1984
specifications of IS0 1161, and are as follows:
30length 1 = 178 + 1 mm
width w = 162 + 1 mm
height h = 118 + 1 mm
mass 9.60 - 9.75 kg + 2 %
The corner elements are interchangeable, besides
they can be manufactured in a range of dimensions for
repair purposes.
1 33~3~
According to embodiment 1 the corner element
consists of a shell element "A" made of a 10 mm thick plate
bent to form a "U" profile with an inner bending radius of
Rmin= a/2 mm, and of a shell element "B" made of a 8 mm thick
plate to form an "L" profile with an inner, bending radius
of Rmin= a/2 mm. The suitable holes are on the shell element
"A", while on the shell element "B" there are no holes at
all. The distance inserts C1, C2 and C4 of the shell
elements "A" of corners in the lower row are seated at the
inner side of the holes, their position is defined by an
orienting gauge. On the shell elements "A" of corners in
the upper row there are distance inserts marked C2, C3 and
C4 .
By defining the hole size on the shell element
"A" it can be determined whether the corner element should
be placed on the upper or lower part of the container. The
mirror image of a shell element can be produced either by
bending the blank from which an element is made in the
opposite direction or by inverting the blank.
The spare parts listed above are assembled in the
orienting gauge and, having checked the size, are fixed by
tack welds. The next operation is the continuous welding
of single-fillet welds.
The last phase is the working of the inlet slopes
(6 x 45) at the outer side of the holes.
When the corner elements are finished, their
surface cleaning takes place.
Embodiment 2 is also based on the conception that
corner elements should be constructed by two shell elements
and three distance inserts. Shell element "A" has a hole
on each side. They are cut out of a flat sheet before
bending. Shell element "B" has no holes. The two shell
elements are assembled to construct the corner element in
the same way as described for embodiment 1 (see Figure 7).
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corner element according to the invention,
wherein A and B are the two shell elements,
Cl, C2 and C4 are the distance inserts and
the lines h-h represent the bending edges.
The corner elements arranged in the upper and
lower planes of the container differ only in respect of
the sizes of the holes on their shorter sides; therefore,
the shell elements "A" are manufactured with two
different holes. The shell elements "B" are identical in
the upper and lower rows and are shaped in such a way
that they form the corner element together with their
counterparts "A".
The shell element "A" with a slight modification
can be considered a finished product as it can serve as
the corner element of tank containers.
The size and tolerance values of the corner
element represented in Figs. 1 to 6 meet the 1984
specifications of IS0 1161. Thus its
- length is 1 = 178 + 1 mm
- width is w = 162 - 1 mm
- height is h = 118 + 1 mm
- mass is 9.60 - 9.75 kg + 2 %
(according to version.)
The corner elements are interchangeable, besides
they can be manufactured in gradual dimensions for
repair purposes.
According to version 1 the corner element
consists of a shell element "A" made of a 10 mm thick
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plate bent to form a "U" profile with an inner bending
radius of Rmin= a/2 mm, and of a shell element "B" made
of a 8 mm thick plate to form an "L" profile with an
inner, bending radius of Rmin= a/2 mm. The suitable holes
are on the shell element A, whlle on the shell element "B"
there are no holes at all.
The distance inserts Cl, C2 and C4 of the shell
elements A of corners in the lower row are seated at the
inner side of the holes, their position is defined by an
orienting gauge. On the shell elements A of corners in
the upper row there are distance inserts marked C2, C3
and C4.
By defining the hole size on the shell element A
it is determined that the corner element should be placed
on the upper or lower part of the container. The mirror
image of the shell element can be produced either by
changing the bending direction to the opposite or by the
inversion of the plate.
The spare parts listed above are assembled in the
orienting gauge and, having checked the size, are fixed
by tack welds. The next operation is the continuous
welding of single-fillet welds.
The last phase is the working of the inlet slopes
(6 x 45) at the outer side of the holes.
When the corner elements are finished, their
surface cleaning takes place.
Version 2 is also based on the conception that
corner elements should be constructed by two shell
- 1 334834
- 10 -
elements and three distance inserts. Shell element "A"
has a hole on each side. They are cut out of the out-
spread plate before bending. Shell element "B" has no
holes. The two shell elements a.e assembled to construct
the corner element in the same way as described for
version 1.
