LU87542A1 - CORNER ELEMENT FOR CONTAINERS - Google Patents

Description

ANSLE ELEMENT FOR CONTAINERS

The present invention relates to a corner element made of manganese steel with assembly holes on its three outer sides.

The different types of containers classified according to ISO standards depending on the size (3 to 12.2 m, ie 10 to 40 feet long) and the load capacity (10, 20, 24 and 30 Mph are used to transport piece goods, bulk items, liquids, etc.

The corner elements are placed at the 8 corners of the containers, which makes it easier to lift or assemble them together and to the transport vehicle, either horizontally or vertically. The corner elements are connected by vertical or horizontal supports made of laminated sheets or profiled shapes. In addition to their mobility, lifting and fixing characteristics, it is important that the containers can be stacked (stacked) on top of each other.

According to the conventional technical methods applied up to now, corner elements are steel castings manufactured by container manufacturers and. The finished castings are generally welded by hand or with a low rate of mechanization to the vertical supports or horizontal. Verification of welds is inconvenient and not entirely secure. Among the possible problems presented by the containers, alongside the breakage of the corner elements, there are very commonly ruptures or tears in the welds resulting from a faulty weld. When it needs to be repaired (for example, when the broken corner element needs to be replaced), it is difficult to keep to the original dimensions and clearances and it takes a lot of time and energy. are forced to withdraw defective containers from circulation for a long period of time.

In the October 1985 issue of the scientific journal Cargo Systems. P. Hewitt described tests for molded angles, performed by Sea Containers in cooperation with the Iron and Steel Co. research laboratory and the Trade Association Sheffield Co .. Examinations included various measurements and tests performed on the molded angles made in different countries around the world. The results concerning the Charpy shock energy at low temperature are given in the following table

The right material for manufacturing corner elements must meet the specification of ISO 1496/1 and / or LR 1984, where the values required at -40 * C, with a "V" slot and according to the Charpy method, are the following:

On a test tube of 10x10 mm min. 34 J

On a test tube of 10 x 7.5 mm min. 28 J

On a test tube of 10x5 mm min. 23 J

The Table shows that these necessary conditions are not met by any of the manufacturers listed. This seems to indicate that one of the defects of the molded angles manufactured according to the current state of the art, is constituted by the unsatisfactory value of the impact energy at low temperatures.

A British company called Blair recently developed a corner element which, after a single normalizing heat treatment and 'at -50 "C reaches the energy value at impact of KVmin = 21 J. However, this is not not at the low temperatures that most of the corner elements break in. In fact, according to data provided by major railway companies (such as the West German DB, the French SNCF, and the British BRs) , the damage to the corner elements or the tears in the welds of their supports take place in the range of positive temperatures following rough handling and reloading, as well as during marshalling and grading of railway wagons.

Due to the material composition of the steel castings and the additional dynamic tension resulting from rough handling, their mechanical qualities decrease in the range of negative temperatures. This results in cracks and breaks, which shortens the life of the containers.

According to tests carried out by the Deutsche Bundesbahn, the deceleration measured at the time of braking was 4 g / m / s ^ or in fact exceeded this value, that is to say more than double the estimated value. DB therefore imposes in its specifications the higher value for all the containers it purchases.

Consequently, the only corner elements used for the construction of the containers must be severely tested and manufactured according to strict quality regulations.

The disadvantages of conventional molded steel corner elements are as follows: - the technology of cast steel requires special skill, technique, starting and additional materials and is more expensive and energy consuming; - external defects in the moldings (for example, withdrawal cavities, inclusions, cracks) are only revealed during the processing of the corner elements. Correct repair of these faults is complicated and inconvenient since it requires preheating, a special welding electrode and repeated heat treatment. It's even more complicated when you notice the defect in the finished product; - to produce the specified structure and mechanical qualities, a heat treatment is required which involves additional energy consumption; - at least three sides of the molded corner element must be treated, which in fact represents all six sides, due to the basic planes; - the 8 corner elements required for each container can only be manufactured with four models, shaped and molded separately, it follows from the above that the manufacture of the corner elements according to the specifications is not easy .

The object of the invention is to provide, in order to eliminate the drawbacks of the known method, a new type of corner element which - suitable for mass production as regards the material, the structure and the technology, - saves energy and does not require repeated heat treatment, - is suitable for stacking and - has an energy of. shock at low temperatures in accordance with specifications.

The invention is based on the observation that all the characteristics listed above can be achieved, if the corner elements are made from a steel sheet having a Mn / C ratio of 8 to 12, a content of (P + SÎ of 0.04% max. By weight and a C content of 0.2% max. By weight.

The material of the steel sheets of this composition is homogeneous, it has foldable edges (Rmin = a / 2 mm, where "a" represents the thickness of the sheet) and its impact energy value (KVmin) 3 -4Q * C amounts to 21 J. The thickness of the wall of the corner elements made from this material will be less than that of the molding, so that it is advisable to have spacers attached to the interior faces of the assembly holes, to ensure connection with the fastening elements.

The steel sheet which serves as the basic material of the corner element according to the invention has a homogeneous granular structure even in a direction perpendicular to the rolling direction, and is suitable for undergoing work hardening technology, Sa elongation value (A5) is greater than 22% and its edges are fairly foldable.

The dimensions and degrees of tolerance of the corner elements made from such a material meet even the strictest specifications (for example ISO Π 61). The mass of these corner elements is at least 10% less than that of their cast steel analogues and its dispersion is 2% less than that of the estimated value, they require little additional machining and can be replaced inside the container quickly and easily. The individual stages of their production can be mechanized at a high level, so that robotization is also possible, which allows high precision and reproducibility of production.

The production of the corner element can be based on the work hardening technology which is simpler and consumes little energy. The cut sheets (stamped) are folded and assembled cold. The welding of the elements can be carried out horizontally by robots, by a simple geometrical drawing. The weld foot is fixed and the weld can be reproduced with high precision. The finished product does not require additional heat treatment and the technology for replacing it is much simpler.

Two assembly versions of the corner element according to the invention are shown in Figures 1 to 6. In the second version, the six faces of the corner element are formed from two elements trilateral in shell, whose sides converge towards three edges and a common peak, while the faces of the corner element of the first version meet on two edges, and thus these elements are U-shaped.

Figure 1 shows the top and side views of version 2 of the corner element and its section along line D-E.

Figure 2 shows the model of the shell element "A" of version 2.

Figure 3 shows the model of the shell element "B" of version 2.

Figure 4 shows shell elements A and B with the spacers added from version H.

Figure 5 represents the reported spacers C i, C2, C3 and C4 of version 2. -

FIG. 6 represents the corner element assembled from the shell elements A and B and the spacers added from version 1.

Figure 7 shows the exploded view of version 2 of the corner element according to the invention, in which A and B are the two shell elements, G], C2 and C4 are the added spacers and the hh lines represent the bending edges.

The corner elements arranged in the upper and lower planes of the container differ only in the size of the holes on their shorter sides; the shell elements “A” are therefore manufactured with two different holes. The shell elements “B” are identical in upper and lower rows and are shaped so that they form the angel element with their counterparts. "AT".

It can be considered that the shell element "A" with a slight modification is a finished product in that it can serve as an angel element for tank containers.

The values of dimensions and tolerance of the angel element shown in Figures 1 to 6 meet the 1984 specifications of ISO U 81. Thus, the length is I = 178 ± I mm the width is w = 162 ± 1 mm the height is h = 118 ± 1 mm ia mass is 9.60 - 9.75 hg ± 2% (depending on version)

The corner elements are interchangeable, moreover, they can be manufactured in gradual dimensions for repairs.

According to version 1, the angel element consists of a shell element ,, A, 'made of a 10 mm thick plate folded to form a U-shaped profile with an inner radius of curvature of Rmin = s / 2 mm and a shell element "B" made of an 8 mm thick plate to form an "L" profile with an internal radius of curvature of Rmin = a / 2 mm. The suitable holes are on the shell element “A”, while there is no hole at all on the shell element “B”.

The inserts C] Ü2 and C4 of the shell elements “A” angles in the lower row are placed on the inside of the holes, their position is defined by an assembly template. On the shell elements " At the corners in the upper row there are added spacers C2, C3 and C4.

By defining the size of the holes on the shell element "A", it is determined whether the corner element should be placed on the upper or lower part of the container. The mirror image of the shell member can be produced either by changing the folding direction in an opposite direction or by reversing the sheet.

The spare parts listed above are assembled in the assembly template and, the dimension being checked, are fixed by positioning welds. The next step is to continuously weld the single thread welds.

The last phase is the machining of the entry slopes (6x45 *} on the outside of the holes.

When the corner elements are finished, their surface is cleaned.

Version 2 is also based on the concept that corner elements must be constructed from two shell elements and three added spacers. The shell element "“ has a hole on each side. They are cut from the bent sheet, The shell element "B" has no hole. The two shell elements are assembled to build the corner element as described for version 1.

Claims (3)

2. Corner element according to claim 1, characterized in that it is assembled by welding from shell elements (A and B) produced by work hardening of the steel sheet and added spacers [ G], G2, C3 and G4). 3. Corner element according to claim 2, characterized by shell elements made by bending and / or drawing. 4. angia element according to claim 2, characterized by shell elements welded automatically (robot) and inserts.