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(11) | EP 1 043 206 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Method for assembling railway cars |
| (57) The invention refers to a method for assembling railway cars obtained by joining
together by means of longitudinal welds a floor (10), two body sides (12, 13) and
a roof (14), said floor, body sides and roof being made of aluminium alloy extruded
panels wherein all welds are accomplished working from the outside of the railway
car by means of automated welding arms sliding along all the length of the car. |
[0002] More particularly, the invention refers to a method for assembling a railway car realised by welding aluminium alloy extruded panels.
[0003] The assembling of railway cars having an aluminium alloy car body is traditionally performed preparing separately the floor or ground of the car, the two body sides and the roof, and then welding together these four parts lengthwise.
[0004] At present the welding of various parts is carried out manually by skilled workmen or with the aid of automated welding systems.
[0005] Moreover, floor, body sides and floor are generally obtained each by the junction of a plurality of aluminium alloy extruded panels that are joined together and welded lengthwise on both sides.
[0006] The present extrusion techniques in fact do not allow to obtain aluminium alloy panels having suitable dimensions for realising a whole body side or a roof or a floor of a railway car.
[0007] For aluminium welding it is generally used a welding technique known as "Mig-Mag" welding, by means of manual equipment or by means of automated welding arms.
[0008] An example of a car body of a railway car assembled according to well-known techniques is shown in figure 1. In figure 1, in cross section, are visible a floor 1, two body sides 2, 3 and a roof 4, joined together by internal welds 6, 7, 8, 9 and external welds 6', 7', 8', 9'.
[0009] The floor is made up by the junction of aluminium alloy extruded panels 1a-1g, previously welded together lengthwise, and rests on two lateral supports 5, 5'.
[0010] Likewise, the lateral sides 2 and 3 are made up by the junction of panels 2a-2d and 3a-3d, while the roof 4 comprises five panels 4a-4e.
[0011] The traditional car body assembling method provides initially for welding internally and externally the two body sides 2 and 3 to the floor 1. The internal welds 6 and 7 are made by skilled workmen working inside the car body, while the external welds 6' and 7' are preferably made in an automated way working on the external side of the body by means of welding arms.
[0012] Afterwards the roof 4 is positioned, welding it to the body sides 2 and 3, first manually from the inside, carrying out the internal welds 8, 9 and then from the outside by means of robotized arms carrying out the external welds 8', 9'.
[0013] The manual welds, especially as regards aluminium, whose welding is somewhat critical, have however some drawbacks. First of all a workman is not able to carry out a continuous weld bead, but he is obliged to break it every 30-40 centimetres. At every interruption, the weld oxidises and it is necessary, prior to resume the weld bead, to grind the weld where it has been interrupted. As a railway car can be even 25-30 meters in length, a complete weld could require many working hours in a unfavourable working environment. The workmen working into a car body must therefore wear faceplates for avoiding inhalation of the fumes that originate during welding.
[0014] Moreover, a manual intermittent weld generates often a final product that is not perfectly aligned. On the contrary, a weld obtained by an automated system guarantees a better and constant quality, reduced working times, and total security for workmen.
[0015] A first object of the present invention is therefore to provide an assembling method for an aluminium alloy car body for a railway car that allows to perform in an automated way all the longitudinal welds, overcoming the drawbacks of the prior art.
[0016] Another object of the present invention is to provide an element of a car body for a railway car, obtained by the junction of several extruded aluminium alloy panels, by means of automated welds carried out by a single side, without therefore the necessity of moving or turn over the element during working.
[0017] These objects of the present invention are reached by an assembling method and a car body element as defined in the enclosed claims.
[0018] The aforesaid objects will become more evident from the detailed description of an assembling method and a car body element according to the invention with particular reference to the attached drawings wherein:
Figure 1 is a sectional view of a car body for a railway car assembled according to the prior art;
Figure 2 is a sectional view of the elements forming a junction point between two extruded panels, according to the present invention;
Figure 3 is a sectional view of a junction point between two extruded panels, according to the present invention;
Figure 4 is a sectional view of a first assembling step of a car body for a railway car, according to the present invention;
Figure 5 is a sectional view of a second assembling step of a car body for a railway car, according to the present invention; and
Figure 6 is a sectional view of a third assembling step of a car body for a railway car, according to the present invention.
[0019] With reference to Figures 2 and 3 it is now described an element of a car body for a railway car, formed by the junction by welding of at least two extruded aluminium alloy panels 40, 42 each having an internal wall 40', 42', an external wall 40'', 42'' and two connecting sides 46, 48.
[0020] The connecting sides 46, 48 of two adjacent panels 40 and 42 are so shaped that, when they are joined for welding, the internal wall 40' of a panel is in contact with the corresponding internal wall 42' of the adjacent panel, while the opposed external walls 40'' and 42'' remain spaced forming a longitudinal opening accessible from the outside. That opening allows to perform, working from the outside and therefore possibly by means of automated systems, a continuous weld 39 along the contact line between the internal walls 40', 42'.
[0021] The longitudinal opening has preferably a "V" shaped transversal section, facilitating the automated welding operations.
[0022] Afterwards, the longitudinal opening is closed applying an aluminium alloy junction element 44, preferably having the same length of the panels, suitable for joining the spaced external walls 40'', 42''. Said element 44 is therefore welded, working again on the external side, along contact lines 31, 33 defined between the junction element 44 and the adjacent walls of panels 40 and 42. The junction element 44 has a triangular cross section so that it can be inserted perfectly into the opening.
[0023] In order to make easier the centering of the junction element 44 into the longitudinal opening, in correspondence of the junction between the two internal walls 40', 42' are present engaging means 27, 28 suitable for containing a terminal engaging portion 30 present in the junction element 44, as better visible in figure 3. Said engaging means 27, 28 form a longitudinal groove, over the weld 39, having a shape complementary to the shape of the terminal engaging portion 30.
[0024] The junction element 44, when inserted into the longitudinal opening, rests on two lowered zones 34 and 36 obtained on the extremities of the external walls 42'' and 40'' of the panels, so that its external surface is at the same level then the adjacent surfaces. A port 32 is provided between the terminal engaging portion 30 and the junction element 44 so that, during welding, the element 44 can be pressed against panels 40 and 42 in order to overcome eventual geometrical defects of the parts.
[0025] As the junction element 44 is positioned, starts, by means of an automated welding arm sliding along all the panels length, its welding firstly with panel 41, weld 31 in figure 3, and then with panel 42, weld 33.
[0026] This connecting system allows therefore to join together lengthwise two aluminium alloy extruded panels working on a single side and in a completely automated way.
[0027] Advantageously, using the above illustrated method, it is possible to join together several panels forming a body side, a roof or a floor for a railway car, or join the body sides with the floor or, as described in the assembling method explained below, to join the body sides with the roof.
[0028] With reference to figures 4, 5 and 6 it is now described a method for assembling the car body of a railway car comprising a floor 10, two body sides 12, 13 and a roof 14. Each of these elements has been previously assembled joining lengthwise, by welding, aluminium alloy extruded panels.
[0029] The floor is made up by the junction of a plurality of panels 10a-10g and rests on two lateral supports 15, 15'. Likewise, the lateral sides 12 and 13 are made up by the junction of panels 12a-12d and 13a-13d, while the roof comprises five panels 14a-14e.
[0030] The method according to the invention provides the steps of:
- position the body sides 12, 13 on the two sides of the floor 10 and weld the internal joints 16 and 17 between floor and body sides; advantageously, this operation is feasible automatically thanks to the absence of the roof in this first step (figure 4);
- position the roof 14 on the body sides 12, 13; the joints between roof and body sides are "V" shaped so that the internal walls are joined while the external walls are spaced; in this way it is possible to reach, from the outside of the car, the joints 18, 19 between the internal walls of the extruded panels (figure 5);
- weld, operating from the outside of the car, the internal walls of the panels 12d, 14a and 13d, 14e, in correspondence of the joints 18 and 19 between roof 14 and body sides 12, 13;
- apply in correspondence of each junction between roof and body sides a junction element 25, 26, made of aluminium alloy, suitable for joining the external wall of the roof 14 with the external wall of each body side 12, 13 (figure 6);
- weld, operating from the outside of the car, the joints between the junction element 25, 26 and the roof 14 and between the junction element 25, 26 and the body sides 12, 13 along the corresponding joints 20, 21, 22, 23;
- weld, along all the railway car length, the external joints 47 and 48 between floor 10 and body sides 12, 13.
1. Method for assembling railway cars obtained by joining together, by means of welds,
a floor (10), two body sides (12, 13) and a roof (14), said floor, body sides and
roof being made of aluminium alloy extruded panels, characterised in that said welds
are accomplished from the outside of the railway car.
2. Method according to claim 1, comprising the steps of:
- position the body sides (12, 13) on the two sides of the floor (10) and weld the internal joints (16, 17) between floor and body sides;
- position the roof (14) on the body sides (12, 13), the joints between roof and body sides being so shaped that the internal walls are joined and the external walls are spaced, so that it is possible to reach, from the outside of the car, the joints between the internal walls of the extruded panels;
- weld, operating from the outside of the car, the joints (18, 19) between the internal walls of roof and body sides;
- apply, in correspondence of each junction between roof and body sides, a junction element (25, 26), made of aluminium alloy, suitable for joining the external wall of the roof with the external wall of each body side;
- weld, operating from the outside of the car, the joints between the junction element (25, 26) and the roof and between the junction element (25, 26) and the body sides along the corresponding joints (20, 21, 22, 23);
- weld the external joints (47, 48) between floor and body sides.
3. Method according to claim 2, wherein said welds are accomplished by means of automated
welding arms sliding along all the length of the railway car.
4. Method according to claim 3, wherein the step of welding the internal joints (6, 7)
between floor (10) and body sides (12, 13) is accomplished by means of an automated
welding arm that enters the car through the open upper part of the same car wherein
will be successively applied the roof (14).
5. Element of a car body for a railway car obtained by joining together, by means of
welds, at least two aluminium alloy extruded panels (40, 42) each having an internal
wall (40', 42'), an external wall (40'', 42'') and two connecting sides (46, 48),
characterised in that the connecting sides (46, 48) of adjacent panels (40, 42) are
so shaped that a first wall (40') of a panel is in contact with the corresponding
wall (42') of the adjacent panel, and the opposite walls (40", 42") are on the contrary
spaced apart allowing to accomplish, working on the side opposite to said first walls,
a continuous weld (39) along the contact line between said first walls (40', 42')
and, successively, to apply a junction element (44), made of aluminium alloy, suitable
for joining the spaced walls (40'', 42'') and to weld said junction element (44),
working again on the same side, along the contact lines (31, 33) between said junction
element (44) and the adjacent walls (40'', 42") of the panels.
6. Element according to claim 5, wherein the junction between the two panels has a "V"
shaped transversal section and the junction element (44) has a triangular transversal
section so that it can be inserted into said "V" junction.
7. Element according to claim 6, wherein the junction between the two panels has, in
correspondence of the joint (39) between said first walls (40', 42'), engaging means
(27, 28) suitable for containing an engaging terminal portion (30) present on one
of the vertices of the junction element (44) itself.
8. Element according to claim 5, wherein the weld (39) along the contact line between
said first walls and the following welds (31, 33) along the connecting lines between
said junction element (44) and the adjacent walls (40", 42'') of the panels are accomplished
by means of an automated welding arm sliding along all the length of the element,
without the need of moving or upsetting the element itself.