Welding method and device for railway vehicle

Abstract

The invention relates to the field of railway vehicles, and provides a welding method and device for a railway vehicle. The welding method for the railway vehicle comprises the steps that a base plate is inserted into a groove of a cross beam; a wedge-shaped block is inserted into the groove, the wedge-shaped block makes contact with the lower surface of the base plate, the wedge-shaped block is pushed to move along the groove, and the base plate is gradually jacked up along the first inclined face of the wedge-shaped block till the base plate is lifted till the vertical distance between the upper surface of the base plate and the upper surface of the cross beam is equal to the thickness of the reinforcing plate; the reinforcing plate is placed in a notch of the groove, and the lower surface of the reinforcing plate makes contact with the upper surface of the base plate; and welding a gap between the reinforcing plate and the cross beam in the width direction of the reinforcing plate. The mounting precision of the stiffening plate is improved, batch rapid mounting and dismounting are achieved, positioning welding is not needed when the stiffening plate is mounted in place, the surface of the base plate can help the root of a weld joint to be forcibly formed, and the continuity and consistency of forming of the back of the weld joint are guaranteed.

Description

Technical Field

[0001] The present invention relates to the field of rail vehicles, and provides a welding method and device for rail vehicles. Background Art

[0002] The middle crossbeam assembly is an important part of the aluminum alloy car body underframe. Except for the traction transformer which is hung by a frame under the car body, the rest of the equipment under the car body is hung by the middle crossbeam. Due to the action of vibration, impact, etc. during the operation of the vehicle, this component needs to bear the influence of complex load conditions, and high requirements are put forward for its mechanical properties, especially the quality of the weld seam.

[0003] The existing installation and welding method of the reinforcement plate for the large crossbeam of the motor car is specifically to clean before welding, then position and install the reinforcement plate and weld the reinforcement plate, and finally grind the weld seam. However, due to the limitations of the structures of the crossbeam and the reinforcement plate itself and the welding method, problems such as low installation accuracy of the reinforcement plate caused by clearance fit and small root face design, large weld metal filling amount caused by large groove design, and poor weld root quality caused by free forming on the reverse side are likely to occur. There are defects such as difficult root assembly, difficult weld formation, narrow process window, difficult welding operation, and low production efficiency. Summary of the Invention

[0004] An embodiment of the present invention provides a welding method and device for rail vehicles, which solve one of the defects in the related art, improve the installation accuracy of the reinforcement plate, realize batch rapid installation and disassembly. At the same time, the upper surface of the backing plate contacts the lower surface of the reinforcement plate, ensuring the stability of the horizontal state of the backing plate during the welding process. Moreover, no positioning welding is required after being installed in place, simplifying the welding steps. And the surface of the backing plate can help the weld root to be forced to form, ensuring the continuity and consistency of the back formation of the weld seam, and achieving the effects of high assembly accuracy, good weld formation, high process adaptability, simple operation, and high production efficiency.

[0005] A welding method for rail vehicles provided by an embodiment of the present invention includes:

[0006] Insert a backing plate into the groove of the crossbeam;

[0007] Insert a wedge block into the groove, make the wedge block contact the lower surface of the backing plate, push the wedge block to move along the groove, and gradually lift the backing plate along the first inclined surface of the wedge block until the vertical distance between the upper surface of the backing plate and the upper surface of the crossbeam is the thickness of the reinforcement plate;

[0008] Place the reinforcement plate at the notch of the groove, make the lower surface of the reinforcement plate contact the upper surface of the backing plate;

[0009] Weld the gap between the reinforcement plate and the crossbeam in the width direction of the reinforcement plate.

[0010] According to an embodiment of the present invention, laser-arc hybrid welding is used for single-layer and single-pass welding to weld the gap between the reinforcing plate and the cross beam in its width direction.

[0011] According to an embodiment of the present invention, the reinforcing plate sequentially includes a trapezoidal portion and a rectangular portion along its thickness direction. The bottom surface of the trapezoidal portion is equal in width to and connected with the upper surface of the rectangular portion. The lower surface of the rectangular portion contacts the upper surface of the backing plate, and the rectangular portion is in interference fit with the notch of the groove.

[0012] According to an embodiment of the present invention, the inclined surface of the trapezoidal portion is inclined inward at an angle between 25° and 30° in the direction from the bottom surface to the top surface of the trapezoidal portion. The thickness of the trapezoidal portion is between 2 mm and 3 mm. When the reinforcing plate is processed, the included angle between the rolling fiber direction and its length direction is between 45° and 135°.

[0013] A welding device for a rail vehicle provided by an embodiment of the present invention is applied to the welding method of the rail vehicle as described above and includes:

[0014] A wedge block, the wedge block is provided with a first inclined surface, and the first inclined surface gradually inclines upward along the extending direction of the groove;

[0015] A backing plate, the backing plate is provided with a second inclined surface, the second inclined surface cooperates with the first inclined surface, and the wedge block is adapted to drive the backing plate to switch between a first state and a second state. In the first state, the second inclined surface moves upward along the first inclined surface. In the second state, the second inclined surface is fixed, and the vertical distance between the upper surface of the backing plate and the upper surface of the cross beam is the thickness of the reinforcing plate.

[0016] According to an embodiment of the present invention, the wedge block includes a wedge portion and an extending portion. The wedge portion is located in the groove, one end of the extending portion is connected to the upwardly inclined end of the first inclined surface of the wedge portion, and the other end extends upward from the notch of the groove.

[0017] According to an embodiment of the present invention, the extending portion includes a groove-retreating surface and a groove-entering surface sequentially arranged along the extending direction of the groove. The groove-retreating surface and the groove-entering surface are oppositely arranged. The first inclined surface is smoothly connected to the groove-retreating surface through a transition surface, and the transition surface is an arc surface.

[0018] According to an embodiment of the present invention, the backing plate includes a first plate portion and a second plate portion. The first plate portion is arranged on one side surface of the second plate portion in its thickness direction. The width of the first plate portion is smaller than the width of the second plate portion. The second inclined surfaces are provided at both ends of the side surface of the second plate portion opposite to the first plate portion.

[0019] According to an embodiment of the present invention, the backing plate includes two first plate portions and a second plate portion. The two first plate portions are respectively disposed on two opposite sides of the second plate portion in the thickness direction thereof. The width of the first plate portion is smaller than the width of the second plate portion, and the lengths of the two first plate portions are the same as the length of the second plate portion. A second inclined surface is provided at the end of each second plate portion close to the backing plate.

[0020] According to an embodiment of the present invention, both sides of the first plate portion in its width direction are third inclined surfaces, and the included angle formed by the third inclined surface and the surface of the second plate portion is between 115° and 125°.

[0021] One or more of the above technical solutions in the embodiments of the present invention have at least one of the following technical effects:

[0022] The welding method of the rail vehicle in the embodiment of the present invention is a single-sided welding and double-sided forming process for the large crossbeam reinforcement plate of the aluminum alloy rail vehicle.

[0023] First, install the reinforcement plate at the crossbeam. Insert the backing plate into the groove of the crossbeam, insert the wedge block into the groove, with the first inclined surface of the wedge block facing the notch, and push the wedge block to move along the groove closer to the backing plate. After the first inclined surface contacts the backing plate, continue to push the wedge block, gradually insert the first inclined surface under the backing plate, and the backing plate gradually moves upward along the first inclined surface to achieve the effect of the wedge block jacking up the backing plate until the backing plate is lifted to the set position. The distance between the upper surface of the backing plate and the upper surface of the crossbeam at this set position is the thickness of the reinforcement plate. At this time, the wedge block fixes the backing plate at the set position, and place the reinforcement plate on the upper surface of the backing plate from the notch to complete the installation of the reinforcement plate at the crossbeam. Then, weld the reinforcement plate and the crossbeam. Gaps are formed between the two sides of the reinforcement plate in its width direction and the two side walls of the notch of the crossbeam, and the two gaps are welded respectively to complete the welding of the reinforcement plate and the crossbeam.

[0024] The present invention designs the backing plate and the wedge block as auxiliary welding devices, improves the installation accuracy of the reinforcement plate, realizes batch rapid installation and disassembly. At the same time, the upper surface of the backing plate contacts the lower surface of the reinforcement plate, ensuring the stability of the horizontal state of the backing plate during the welding process. Moreover, no positioning welding is required after installation in place, simplifying the welding steps. And the surface of the backing plate can help the root of the weld to be forced to form, ensuring the continuity and consistency of the back formation of the weld, achieving the effects of high assembly accuracy, good weld formation, high process adaptability, simple operation, and high production efficiency.

[0025] The additional aspects and advantages of the present invention will be partly given in the following description, partly will become obvious from the following description, or be understood through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] To more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0027] Figure 1a is a schematic structural view of a crossbeam provided by the prior art;

[0028] Figure 1b is a schematic structural view of a reinforcing plate provided by the prior art;

[0029] Figure 2a is one of the schematic views of the welding process of the crossbeam and the reinforcing plate provided by the prior art;

[0030] Figure 2b is another schematic view of the welding process of the crossbeam and the reinforcing plate provided by the prior art;

[0031] Figure 2c is still another schematic view of the welding process of the crossbeam and the reinforcing plate provided by the prior art;

[0032] Figure 2d is yet another schematic view of the welding process of the crossbeam and the reinforcing plate provided by the prior art;

[0033] Figure 3a is one of the schematic structural views of the weld after the welding of the crossbeam and the reinforcing plate is completed provided by the prior art;

[0034] Figure 3b is another schematic structural view of the weld after the welding of the crossbeam and the reinforcing plate is completed provided by the prior art;

[0035] Figure 4a is one of the schematic views of the process of the welding method of the rail vehicle provided by the embodiment of the present invention;

[0036] Figure 4b is another schematic view of the process of the welding method of the rail vehicle provided by the embodiment of the present invention;

[0037] Figure 4c is still another schematic view of the process of the welding method of the rail vehicle provided by the embodiment of the present invention;

[0038] Figure 4d is yet another schematic view of the process of the welding method of the rail vehicle provided by the embodiment of the present invention;

[0039] Figure 4e is still another schematic view of the process of the welding method of the rail vehicle provided by the embodiment of the present invention;

[0040] Figure 4f It is the sixth of the process diagrams of the welding method of the rail vehicle provided by the embodiment of the present invention;

[0041] Figure 4g It is the seventh of the process diagrams of the welding method of the rail vehicle provided by the embodiment of the present invention;

[0042] Figure 4h It is the eighth of the process diagrams of the welding method of the rail vehicle provided by the embodiment of the present invention;

[0043] Figure 5 It is Figure 4e The structural schematic diagram of the local P;

[0044] Figure 6a It is the structural schematic diagram of the first state of the welding device of the rail vehicle provided by the embodiment of the present invention;

[0045] Figure 6b It is the structural schematic diagram of the second state of the welding device of the rail vehicle provided by the embodiment of the present invention;

[0046] Figure 7a It is one of the structural schematic diagrams of the backing plate of the welding device of the rail vehicle provided by the embodiment of the present invention;

[0047] Figure 7b It is two of the structural schematic diagrams of the backing plate of the welding device of the rail vehicle provided by the embodiment of the present invention;

[0048] Figure 8a It is three of the structural schematic diagrams of the backing plate of the welding device of the rail vehicle provided by the embodiment of the present invention;

[0049] Figure 8b It is four of the structural schematic diagrams of the backing plate of the welding device of the rail vehicle provided by the embodiment of the present invention;

[0050] Figure 8c It is five of the structural schematic diagrams of the backing plate of the welding device of the rail vehicle provided by the embodiment of the present invention;

[0051] Figure 9a It is one of the structural schematic diagrams of the wedge block of the welding device of the rail vehicle provided by the embodiment of the present invention;

[0052] Figure 9b It is two of the structural schematic diagrams of the wedge block of the welding device of the rail vehicle provided by the embodiment of the present invention;

[0053] Figure 10 It is one of the structural schematic diagrams of the reinforcing plate of the welding method of the rail vehicle provided by the embodiment of the present invention;

[0054] Figure 11It is the second schematic structural diagram of the reinforcing plate in the welding method of the rail vehicle provided by the embodiment of the present invention;

[0055] Figure 12 It is the schematic flow diagram of the welding method of the rail vehicle provided by the embodiment of the present invention;

[0056] Figure 13 It is the schematic diagram of the weld seam after welding in the welding method of the rail vehicle provided by the embodiment of the present invention;

[0057] Figure 14a It is one of the comparison tables of the tensile properties of the arc welding and composite welding joint specimens in the welding method of the rail vehicle provided by the embodiment of the present invention;

[0058] Figure 14b It is the second comparison table of the tensile properties of the arc welding and composite welding joint specimens in the welding method of the rail vehicle provided by the embodiment of the present invention.

[0059] Reference numerals:

[0060] 100, wedge block; 110, first inclined surface; 120, wedge portion; 130, extension portion; 131, groove retreat surface; 132, groove entry surface; 133, transition surface;

[0061] 200, backing plate; 210, second inclined surface; 220, first plate portion; 221, third inclined surface; 230, second plate portion;

[0062] 300, cross beam; 310, groove; 311, groove opening;

[0063] 400, reinforcing plate; 410, trapezoidal portion; 420, rectangular portion. Detailed implementation manners

[0064] The following further describes in detail the implementation manners of the present invention with reference to the drawings and embodiments. The following embodiments are used to illustrate the present invention, but cannot be used to limit the scope of the present invention.

[0065] In the description of the embodiments of the present invention, it should be noted that the orientation or positional relationships indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the embodiments of the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0066] In the description of the embodiments of the present invention, it should be noted that, unless otherwise clearly defined and limited, the terms "connected" and "coupled" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific situations.

[0067] In the embodiments of the present invention, unless otherwise clearly defined and limited, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may be that the first feature is directly above or obliquely above the second feature, or merely means that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "below" and "beneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely means that the horizontal height of the first feature is lower than that of the second feature.

[0068] In the description of this specification, the descriptions with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the embodiments of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, without conflict, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0069] Such as Figure 1a And Figure 1bAs shown in the figure, the large crossbeam 300 is an important load-bearing component of the aluminum alloy car body of the EMU. It is formed by welding the 6005A-T6 crossbeam 300 profile with a thickness of 9 mm and the 5083-O reinforcing plate 400 with a thickness of 6 mm. A through groove 310 is formed along the length direction inside the crossbeam 300 profile, and the cross-sectional shape of the groove 310 is convex, the width of the groove opening 311 becomes narrower, the cross-sectional shape of the reinforcing plate 400 is an isosceles trapezoid, and the two waists of the trapezoid are the grooves of the reinforcing plate 400. The length direction of the reinforcing plate 400 is the same as the extending direction of the groove 310. The conventional welding method is to weld the reinforcing plate 400 with a length of 180 mm, a width of 22 mm, and a thickness of 6 mm at the position of the groove opening 311 of the groove 310 of the crossbeam 300. The top edge of the reinforcing plate 400 is flush with the upper surface of the crossbeam 300, and the bottom edge of the reinforcing plate 400 is located inside the groove opening 311. First, pre-welding cleaning is carried out, then the reinforcing plate 400 is positioned and installed on the crossbeam 300, and then the reinforcing plate 400 is welded to the crossbeam 300, and finally the weld seam is polished. However, there are the following problems in the installation and welding of the reinforcing plate 400 of the large crossbeam 300:

[0070] (1) The low installation accuracy of the reinforcing plate 400 is caused by the clearance fit and the small root face design

[0071] As Figure 2a , Figure 2b , Figure 2c and Figure 2d shown, the installation requirement of the reinforcing plate 400 is fixed to the crossbeam 300 by welding two tack welds with a length of 10 mm - 15 mm on each of the two side grooves. Since there is a thickness difference of 3 mm between the thickness of the reinforcing plate 400 and the part of the crossbeam 300 forming the groove opening 311, and the width of the reinforcing plate 400 is 2 mm smaller than the groove opening 311 of the crossbeam 300, after the first tack weld is made on one side groove, due to the shrinkage of the weld seam, angular deformation of the reinforcing plate 400 occurs, resulting in uncontrollable dimensions between the reinforcing plate 400 and the upper surface of the crossbeam 300. At the same time, the transverse shrinkage deformation causes the root clearance to be uncontrollable, that is, the vertical distance between the bottom edge of the reinforcing plate 400 and the side wall of the groove opening 311 of the crossbeam 300 changes. The root clearance of this side groove will shrink to less than 0.5 mm. When the second tack weld is made on the other side groove, the root clearance of the other side groove becomes more than 1.5 mm, resulting in inconsistent root clearances of the two side weld seams.

[0072] (2) The large groove design results in a large amount of weld metal filling

[0073] As Figure 3a and 3bAs shown, the reinforcement plate 400 made of aluminum alloy is welded by arc welding (MIG metal inert gas welding). Due to the structural limitation of the cross beam 300, the width of the notch 311 is 22 mm, so the distance between the two weld seams is only 22 mm, resulting in the overlap of the heat affected zones and causing stress concentration problems; the single V-joint form has high requirements for welder skills and is prone to quality defects such as incomplete fusion at the root of the groove. To ensure the welding quality, a large-angle groove of 55° and two-layer two-pass welding are currently used, bringing bottleneck problems such as large deformation, high stress, performance degradation, and strength loss.

[0074] (3) The free forming on the reverse side results in poor quality of the weld root

[0075] As Figure 3a and 3b shown, since the single-sided welding and double-sided forming of the weld seam between the cross beam 300 and the reinforcement plate 400 are ensured by the skills of the operator, it is easy to cause the problem of unstable back forming quality. The accuracy of the reinforcement plate 400 during installation and positioning is low, the root gap of the weld seam is inconsistent, and the adaptation parameters need to be adjusted at any time, with a narrow process window. It is difficult to achieve full penetration at the tack welding position between the reinforcement plate 400 and the cross beam 300, greatly increasing the operation difficulty, low production efficiency, and also having an adverse impact on the full penetration and forming consistency of the weld root.

[0076] As Figures 4a to 4h , Figure 5 and Figure 12 shown, the welding method of the rail vehicle provided by the embodiment of the present invention includes:

[0077] Insert the backing plate 200 into the groove 310 of the cross beam 300;

[0078] Insert the wedge block 100 into the groove 310, make the wedge block 100 contact the lower surface of the backing plate 200, push the wedge block 100 to move along the groove 310, and gradually lift the backing plate 200 along the first inclined surface 110 of the wedge block 100 until the vertical distance between the upper surface of the backing plate 200 and the upper surface of the cross beam 300 is the thickness of the reinforcement plate 400;

[0079] Place the reinforcement plate 400 at the notch 311 of the groove 310, and make the lower surface of the reinforcement plate 400 contact the upper surface of the backing plate 200;

[0080] Weld the gap between the reinforcement plate 400 and the cross beam 300 in its width direction.

[0081] The welding method of the rail vehicle in the embodiment of the present invention is a single-sided welding and double-sided forming process for the reinforcement plate of the large cross beam of the aluminum alloy rail vehicle.

[0082] First, install the reinforcement plate 400 at the cross beam 300. Insert the backing plate 200 into the groove 310 of the cross beam 300, and insert the wedge block 100 into the groove 310. The first inclined surface 110 of the wedge block 100 faces the notch 311, and push the wedge block 100 to move along the groove 310 towards the backing plate 200. After the first inclined surface 110 contacts the backing plate 200, continue to push the wedge block 100, and gradually insert the first inclined surface 110 under the backing plate 200. The backing plate 200 will gradually move upward along the first inclined surface 110, achieving the effect that the wedge block 100 jacks up the backing plate 200 until the backing plate 200 is lifted to the set position. The distance between the upper surface of the backing plate 200 and the upper surface of the cross beam 300 at this set position is the thickness of the reinforcement plate 400. At this time, the wedge block 100 fixes the backing plate 200 at the set position. Place the reinforcement plate 400 on the upper surface of the backing plate 200 through the notch 311 to complete the installation of the reinforcement plate 400 at the cross beam 300. Then, weld the reinforcement plate 400 and the cross beam 300. Gaps are formed between the two sides in the width direction of the reinforcement plate 400 and the two side walls of the notch 311 of the cross beam 300, and the two gaps are welded respectively to complete the welding of the reinforcement plate 400 and the cross beam 300.

[0083] In the present invention, by designing the backing plate 200 and the wedge block 100 as auxiliary welding devices, the installation accuracy of the reinforcement plate 400 is improved, batch and rapid installation and disassembly are realized. At the same time, the upper surface of the backing plate 200 contacts the lower surface of the reinforcement plate 400, ensuring the stability of the horizontal state of the backing plate 200 during the welding process. Moreover, no positioning welding is required after installation in place, simplifying the welding steps. In addition, the surface of the backing plate 200 can help the root of the weld to be forced to form, ensuring the continuity and consistency of the back formation of the weld, achieving the effects of high assembly accuracy, good weld formation, high process adaptability, simple operation, and high production efficiency.

[0084] In this embodiment, before installing the backing plate 200 into the groove 310 of the cross beam 300, pre-welding cleaning can also be carried out to clean the oil stains and dirt in the areas 20 mm away from the ends at both ends of the large cross beam 300 and the reinforcement plate 400. After the welding of the cross beam 300 and the reinforcement plate 400 is completed, disassemble the backing plate 200 and the wedge block 100. First, push the wedge block 100 to gradually move away from the backing plate 200 along the extending direction of the groove 310. The backing plate 200 will move downward along the first inclined surface 110 accordingly. The wedge block 100 is completely separated from the backing plate 200, and the backing plate 200 falls to the bottom of the groove 310. Finally, take out the backing plate 200 and the wedge block 100 from the groove 310. Post-welding grinding can also be carried out. Use a grinding tool to grind the excess height of the weld at the upper surface of the cross beam 300 to ensure the smoothness of the weld surface.

[0085] According to an embodiment of the present invention, laser-arc hybrid welding is used for single-layer single-pass welding to weld the gap between the reinforcement plate 400 and the cross beam 300 in its width direction.

[0086] In this embodiment, for the welding improvement of the gap between the reinforcement plate 400 and the cross beam 300, laser-arc hybrid welding is adopted and changed to the single-layer single-pass welding method. Compared with the arc welding used in the prior art, the laser-arc hybrid welding in this embodiment optimizes the welding method, realizes fast welding with low heat input, and is more adaptable to the single-layer single-pass welding method at the same time. While ensuring the structural strength after welding and adapting to the groove size of the reinforcement plate 400, it greatly reduces the welding filling amount, reduces the steps and environment of pre-welding preparation, welding process and post-welding grinding, improves the welding quality and greatly improves the production efficiency at the same time, forming a method and process for rapid installation of rail vehicles.

[0087] By using laser-arc hybrid welding, the bottleneck problems existing in the existing arc welding mode can be effectively solved. Utilizing the characteristics of the laser heat source being concentrated and having strong penetration, the groove is optimized and designed to form a refined energy control with a large root face and a narrow groove, making the welding process more stable, greatly reducing the wire filling amount and the welding line energy; in the deep penetration welding mode, the weld seam is simplified from 2 layers and 2 passes to a single pass, ensuring stable welding.

[0088] As Figure 10 shown, according to an embodiment of the present invention, the reinforcement plate 400 sequentially includes a trapezoidal portion 410 and a rectangular portion 420 along its thickness direction. The bottom surface of the trapezoidal portion 410 is equal in width to and connected with the upper surface of the rectangular portion 420. The lower surface of the rectangular portion 420 contacts the upper surface of the backing plate 200, and the rectangular portion 420 has an interference fit with the notch 311 of the groove 310.

[0089] In this embodiment, the reinforcement plate 400 is divided into a trapezoidal portion 410 and a rectangular portion 420 from top to bottom along its thickness direction. The cross-sectional shape of the trapezoidal portion 410 is an isosceles trapezoid. The shorter fixed side forms the upper surface of the reinforcement plate 400, and the longer bottom side forms the bottom surface of the trapezoidal portion 410, which is connected to the upper surface of the rectangle. The lower surface of the rectangle forms the lower surface of the reinforcement plate 400. Since the width dimension of the reinforcement plate 400 is equivalent to the width dimension of the notch 311 of the groove 310 of the cross beam 300, an interference fit is formed after the reinforcement plate 400 is placed into the notch 311 of the groove 310. When the reinforcement plate 400 contacts the backing plate 200, the reinforcement plate 400 is installed in place. The interference fit makes the reinforcement plate 400 fixed after being placed into the notch 311, and no positioning welding is required.

[0090] The interference amount of the interference fit between the reinforcement plate 400 and the cross beam 300 is 0.1 mm to 0.2 mm.

[0091] As Figure 11As shown, according to an embodiment of the present invention, the inclined surface of the trapezoidal portion 410 is inclined inward at an angle between 25° and 30° in the direction from the bottom surface to the top surface of the trapezoidal portion 410. The thickness of the trapezoidal portion 410 is between 2 mm and 3 mm. When the reinforcing plate 400 is processed, the angle between the rolling fiber direction and its length direction is between 45° and 135°.

[0092] In this embodiment, the cross-sectional shape of the trapezoidal portion 410 is an isosceles trapezoid. The base angle range of the isosceles trapezoid is 25° to 30°, and the height range of the isosceles trapezoid is 2 mm to 3 mm. Thus, the groove angle and depth formed by the inclined surface of the trapezoidal portion 410 are controlled, and further the size of the weld seam is controlled to reduce the filling amount during welding.

[0093] When the reinforcing plate 400 is processed, the rolling fiber direction makes a certain angle with the weld groove. The angle range is between 45° and 135°, and 90° is the optimal angle. By improving the design and cutting direction of the reinforcing plate 400, it is ensured that the welding shrinkage direction of the rail vehicle is parallel to the rolling fiber direction of the reinforcing plate 400 itself, improving the tensile delamination resistance of the reinforcing plate 400 and increasing the assembly accuracy and the ability to resist welding shrinkage stress.

[0094] The reinforcing plate 400 adopts a design with a small groove and a large root face. As shown in Table 1 below, the root face is the side edge that extends along the length direction of the rectangular portion 420 and is vertically arranged. The root face dimension is the difference between the thickness t2 of the reinforcing plate 400 and the thickness h of the trapezoidal portion 410. By connecting and cooperating the root face with the side wall of the notch 311 of the cross beam 300, since the root face of the reinforcing plate 400 is large enough to play a constraining role, it can be ensured that the upper surface of the reinforcing plate 400 always remains flush with the upper surface of the cross beam 300 during welding without skew deformation.

[0095] Table 1

[0096]

[0097] As Figure 6a and Figure 6b shown, a welding device for a rail vehicle provided by an embodiment of the present invention is applied to the welding method of the rail vehicle as described in the above embodiment, and includes a wedge block 100 and a backing plate 200. The wedge block 100 is provided with a first inclined surface 110, and the first inclined surface 110 gradually inclines upward along the extending direction of the groove 310. The backing plate 200 is provided with a second inclined surface 210, and the second inclined surface 210 cooperates with the first inclined surface 110. The wedge block 100 is adapted to drive the backing plate 200 to switch between a first state and a second state. In the first state, the second inclined surface 210 moves upward along the first inclined surface 110. In the second state, the second inclined surface 210 is fixed, and the vertical distance between the upper surface of the backing plate 200 and the upper surface of the cross beam 300 is the thickness of the reinforcing plate 400.

[0098] The welding device of the rail vehicle according to the embodiment of the present invention is a single-sided welding and double-sided forming device for the large crossbeam reinforcement plate of an aluminum alloy rail vehicle, mainly composed of a wedge block 100 and a backing plate 200. When the backing plate 200 is inserted into the groove 310 of the crossbeam 300, it is necessary to ensure that the second inclined surface 210 of the backing plate 200 can face the bottom of the groove 310. When the wedge block 100 is inserted into the groove 310 of the crossbeam 300, the first inclined surface 110 of the wedge block 100 gradually slopes upward from the bottom of the groove 310 towards the notch 311, forming a state where the lowest end of the first inclined surface 110 is closer to the second inclined surface 210 of the backing plate 200 than the highest end. The first state is the process of pushing the wedge block 100 closer to the backing plate 200, and the first inclined surface 110 also gradually approaches the second inclined surface 210 until it is in complete contact and fit with the second inclined surface 210. As the wedge block 100 further moves, under the combined action of the second inclined surface 210 and the first inclined surface 110, the backing plate 200 is gradually lifted to the set position. The second state is the state where the wedge block 100 fixes the backing plate 200 at the set position. In this state, the welding of the reinforcement plate 400 and the crossbeam 300 can be carried out.

[0099] As Figure 9a and Figure 9b shown, according to an embodiment of the present invention, the wedge block 100 includes a wedge portion 120 and an extension portion 130. The wedge portion 120 is located in the groove 310. One end of the extension portion 130 is connected to the upwardly inclined end of the first inclined surface 110 of the wedge portion 120, and the other end extends upward from the notch 311 of the groove 310.

[0100] In this embodiment, the wedge block 100 is sequentially divided into a wedge portion 120 and an extension portion 130 from bottom to top. The wedge block 100 is integrally L-shaped. The first inclined surface 110 is the upper surface of the wedge portion 120, and the highest end of the first inclined surface 110 is the end connected to the extension portion 130. After the wedge block 100 is placed in the groove 310 of the crossbeam 300, the extension portion 130 can extend out from the notch 311. By acting on the extension portion 130, the advancement and retraction of the wedge block 100 along the extension direction of the groove 310 can be realized.

[0101] It can be understood that the width direction of the wedge block 100 is the same as the width direction of the groove 310. The width of the wedge block 100 is smaller than the width of the notch 311 of the groove 310, and the height of the wedge block 100 is greater than the depth of the groove 310.

[0102] According to an embodiment of the present invention, the extension portion 130 includes a groove retreating surface 131 and a groove advancing surface 132 arranged in sequence along the extension direction of the groove 310. The groove retreating surface 131 and the groove advancing surface 132 are oppositely arranged. The first inclined surface 110 is smoothly connected to the groove retreating surface 131 through a transition surface 133, and the transition surface 133 is an arc surface.

[0103] In this embodiment, along the direction from the lowest end to the highest end of the first inclined surface 110, a groove retreating surface 131 and a groove advancing surface 132 are sequentially arranged on the extension part 130. That is, the direction from the groove advancing surface 132 to the groove retreating surface 131 is the direction in which the wedge block 100 moves closer to the backing plate 200 in the groove 310, and the direction from the groove retreating surface 131 to the groove advancing surface 132 is the direction in which the wedge block 100 moves away from the backing plate 200 in the groove 310. The groove retreating surface 131 and the first inclined surface 110 are smoothly connected through a transition surface 133. The transition surface 133 is an arc-shaped surface sunken towards the bottom of the groove 310. The transition surface 133 is the supporting surface of the backing plate 200. In the second state, the end of the backing plate 200 provided with the second inclined surface 210 abuts against the transition surface 133 and remains fixed.

[0104] When pushing the wedge block 100, a rubber hammer can be used to continuously strike the groove advancing surface 132 until the backing plate 200 moves to the transition surface 133, and the wedge block 100 presses the spacer tightly, completing the installation of the wedge block 100 and the backing plate 200. When retracting the wedge block 100, a rubber hammer can be used to continuously strike the groove retreating surface 131 until the wedge block 100 is separated from the backing plate 200, the backing plate 200 loses support and falls into the groove 310 of the cross beam 300, and then the backing plate 200 and the wedge block 100 are taken out to complete the disassembly of the wedge block 100 and the backing plate 200. The whole process is simple, fast and convenient to operate.

[0105] In this embodiment, the wedge block is made of steel plate. L’ is the length of the backing plate 200, b is the width of the trapezoidal part 410 of the backing plate 200; θ is the inclination angle of the second inclined surface 210 of the backing plate 200. The dimensions of the wedge block 100 are designed as shown in Table 2 below.

[0106] Table 2

[0107]

[0108] As Figure 7a and Figure 7b shown, according to an embodiment of the present invention, the backing plate 200 includes a first plate part 220 and a second plate part 230. The first plate part 220 is arranged on one side surface of the second plate part 230 in its thickness direction. The width of the first plate part 220 is smaller than the width of the second plate part 230. Second inclined surfaces 210 are provided at both ends of the side surface of the second plate part 230 opposite to the first plate part 220.

[0109] In this embodiment, the backing plate 200 is a single-sided backing plate 200. The first plate part 220 is arranged on the upper surface of the second plate part 230. That is, the upper surface of the first plate part 220 is the upper surface of the backing plate 200, and the lower surface of the second plate part 230 is the lower surface of the backing plate 200. The width of the first plate part 220 is smaller than that of the second plate part 230, which is equivalent to that the first plate part 220 is a convex structure formed on the upper surface of the second plate part 230.

[0110] In the second state, the upper surfaces of the second plate portions 230 on both sides in the width direction of the first plate portion 220 abut against the notch 311 of the cross beam 300, and the first plate portion 220 enters the notch 311 to support the reinforcing plate 400. The lower surfaces of the second plate portions 230 are provided with second inclined surfaces 210 at both ends in the length direction thereof. No matter which end is inserted into the groove 310 of the cross beam 300 first, the cooperation and installation of the wedge block 100 and the backing plate 200 can be realized, and the versatility is stronger. The depressions on both sides of the backing plate 200 formed by the cooperation of the first plate portion 220 and the second plate portion 230 play a role in forcing the formation of the root weld, ensuring the forming quality and consistency of the weld root.

[0111] As Figure 8a 、 Figure 8b and Figure 8c shown, according to an embodiment of the present invention, the backing plate 200 includes two first plate portions 220 and a second plate portion 230. The two first plate portions 220 are respectively disposed on both sides in the thickness direction of the second plate portion 230. The width of the first plate portion 220 is smaller than the width of the second plate portion 230. The lengths of the two first plate portions 220 are the same as the length of the second plate portion 230. A second inclined surface 210 is provided at each end of each second plate portion 230 close to the backing plate 200.

[0112] In this embodiment, the backing plate 200 is a double-sided backing plate 200. There are two first plate portions 220, which are respectively disposed on the upper surface and the lower surface of the second plate portion 230. That is, the upper surface of one first plate portion 220 is the upper surface of the backing plate 200, and the lower surface of the other first plate portion 220 is the lower surface of the backing plate 200. The width of the first plate portion 220 is smaller than that of the second plate portion 230, which is equivalent to that the first plate portion 220 is a convex structure formed on the upper surface and the lower surface of the second plate portion 230.

[0113] In the second state, the upper surfaces of the second plate portions 230 on both sides in the width direction of the first plate portion 220 abut against the notch 311 of the cross beam 300, and the first plate portion 220 enters the notch 311 to support the reinforcing plate 400. A second inclined surface 210 is provided at one end in the length direction of the lower surface of the first plate portion 220. The two second inclined surfaces 210 can be provided at the same end or at both ends respectively. No matter which first plate portion 220 contacts the bottom of the groove 310, the function of the backing plate 200 can be realized, and the cooperation and installation of the wedge block 100 and the backing plate 200 can be realized, and the versatility is stronger. The depressions on both sides of the backing plate 200 formed by the cooperation of the first plate portion 220 and the second plate portion 230 play a role in forcing the formation of the root weld, ensuring the forming quality and consistency of the weld root.

[0114] According to an embodiment of the present invention, both side surfaces of the first plate portion 220 in its width direction are third inclined surfaces 221, and the included angle formed by the third inclined surfaces 221 and the surface of the second plate portion 230 is between 115° and 125°.

[0115] In this embodiment, the cross-sectional shape of the first plate portion 220 is an isosceles trapezoid, and the longer base of the isosceles trapezoid is connected to the second plate portion 230. The base angle range of the isosceles trapezoid is 55° to 75°.

[0116] The backing plate 200 can be divided into single-sided and double-sided forms. Made of stainless steel material, as shown in Table 3 and Table 4 below, taking the design of both sides of the backing plate 200 as an example, its main function is to support and compensate for the thickness difference between the reinforcing plate 400 and the cross beam 300 during the installation of the reinforcing plate 400, ensuring that the upper surface of the reinforcing plate 400 is flush with the upper surface of the cross beam 300 after the installation of the reinforcing plate 400 is completed. The height T' of the first plate portion 220 is the difference between the depth t1 of the notch 311 of the cross beam 300 and the thickness t2 of the reinforcing plate 400.

[0117] Table 3

[0118]

[0119] Table 4

[0120]

[0121] The macro diagram of the weld after welding is completed by the welding method of the present invention, as Figure 13 shown.

[0122] Statistics were carried out on the weld width and reinforcement height dimensions, as shown in Table 5 specifically. The weld width and reinforcement height of arc welding are 13.8 mm and 1.3 mm respectively, and those of composite welding are 8.1 mm and 0.9 mm respectively, which are decreased by 41.3% and 30.8% respectively compared with arc welding. The reduction of the weld size is beneficial to the workload of the weld grinding process.

[0123] Table 5

[0124]

[0125] X-ray flaw detection was used to detect the internal defect conditions of the arc welds and composite welds of the in-service structural parts of the middle cross beam. The results show that there are no crack defects inside the welds of both, and the porosity defects meet the requirements of ISO 10042 Class B welds.

[0126] According to the previous distribution law of porosity defects in the composite welding of the middle cross beam, the pores are mostly concentrated at the junction of the back reinforcing plate and the profile. Therefore, the porosity situation of the weld can be clearly observed by machining the back weld flat. Therefore, for the porosity defect situation when adding a backing to the back, no pores are found by this method.

[0127] Due to the dimensional problems of the existing vehicle structure parts of the middle crossbeam, it is impossible to fabricate tensile property test specimens. Therefore, test plates with the same material and the same groove are used to fabricate weld simulation parts. After flaw detection shows no defects, samples are taken for tensile property testing. The specific results are as Figure 14a and Figure 14b shown.

[0128] It can be found through comparison that the average tensile strengths of the arc welding and composite welding joints are 180 MPa and 218 MPa respectively, reaching 65.3% and 79.4% of the base metal respectively. The tensile strength of the composite welding joint is 14.1% higher than that of the arc welding joint. In addition, the tensile fracture positions of the arc welding joints all appear at the weld center, and the tensile fracture positions of the composite joints all appear near the fusion line, which also indicates that the tensile property of the composite welding joint is superior to that of the arc welding joint.

[0129] During the vehicle operation process, the middle crossbeam assembly is affected by alternating loads such as vibration and impact of the suspended equipment. Therefore, the fatigue properties of its weld simulation parts are compared and verified. The test conditions are room temperature and atmospheric environment, the loading stress value is the fatigue limit design value of 89 MPa for smooth joints, and the stress ratio is 0. The test results are shown in Table 6. The fatigue property of the composite welding joint fully meets the requirement of the design value of 89 MPa. According to the previous test results of the performance of large components of the high-speed maglev aluminum alloy car body, the fatigue property of composite welding is significantly improved compared with arc welding; the fatigue limit of the composite welding joint of the middle crossbeam assembly will be further clarified later.

[0130] Table 6

[0131]

[0132] From the requirements of cost reduction, efficiency improvement and green manufacturing, a comparative analysis is carried out on the welding materials, energy consumption, post-weld grinding and welding efficiency of the middle crossbeam assemblies welded by arc welding and composite welding.

[0133] 1. Welding materials

[0134] According to the groove dimensions of arc welding and composite welding, the required wire amount for filling is simplified and calculated. Among them, the filling area of the arc welding groove is 17.85 mm 2 , and the filling area of the composite welding groove is 1.15 mm 2 . The wire filling amount of composite welding is about 94% less than that of arc welding.

[0135] 2. Energy consumption

[0136] At present, the weld of the middle crossbeam in arc welding consists of two layers and two passes. For the first pass: current 200±10A, voltage 23±1V, welding speed 9.5±1mm / s; for the second pass: current 185±10A, voltage 22.5±1V, welding speed 7±1mm / s; the calculated heat input is about 1080J / mm.

[0137] The composite welding uses a single pass, and the process parameters are: laser power 6800W, current 190A, voltage 22.5V, welding speed 33.3mm / s; the calculated heat input is about 333J / mm.

[0138] Therefore, the heat input and the corresponding energy consumption of the composite welding are about 70% less than those of the arc welding.

[0139] 3. Grinding after welding

[0140] According to the weld width and reinforcement dimensions of the arc welding and composite welds (Table 3), a simple calculation was made for the grinding amount of the weld. The grinding amount per unit length of the arc welding weld is 17.94mm 2 , and the grinding amount per unit length of the composite welding weld is 7.29mm 2 , which is about 60% less than that of the arc welding.

[0141] 4. Welding efficiency

[0142] The length of a single weld of the middle crossbeam is 150mm. In arc welding, two layers and two passes are used, and the welding speeds are 9.5mm / s and 7mm / s respectively. If only the welding time is considered and the time for cleaning the interlayer black ash is ignored, it takes about 37s to complete the welding; the composite welding uses a single pass, and the welding speed is 33.3mm / s, and it takes about 4.5s to complete the welding, and the welding efficiency is increased by 88% compared with the arc welding.

[0143] 4. Composite welding

[0144] The composite welding optimized process (process parameters: laser in front, arc behind, laser power 6800W, current 190A, welding speed 2m / min, laser two-sided angle 84.5°, arc two-sided angle 120°, defocus amount +2mm, spot diameter 0.8mm, dry elongation 16mm) was used to conduct welding verification for 12 middle crossbeams with a total of 48 welds at one time. Through the inspection after welding, the performance meets the design requirements.

[0145] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A welding method for a rail vehicle, characterized in that: include: Inserting the backing plate (200) into the groove (310) of the crossbeam (300); Inserting a wedge block (100) into the groove (310) so that the wedge block (100) contacts the lower surface of the pad (200), pushing the wedge block (100) to move along the groove (310), and gradually lifting the pad (200) along the first inclined surface (110) of the wedge block (100), until the pad (200) is lifted to a point where the vertical distance between the upper surface of the pad (200) and the upper surface of the beam (300) is the thickness of the reinforcing plate (400); Placing the reinforcing plate (400) in the notch (311) of the groove (310) so that the lower surface of the reinforcing plate (400) contacts the upper surface of the pad (200); The gap between the reinforcing plate (400) and the crossbeam (300) is welded in the width direction thereof.

2. The welding method for a rail vehicle according to claim 1, characterized in that: Laser-arc hybrid welding is used to perform single-layer single-pass welding to weld the gap between the reinforcing plate (400) and the crossbeam (300) in the width direction thereof.

3. The welding method for a rail vehicle according to claim 1, characterized in that: The reinforcing plate (400) comprises a trapezoidal portion (410) and a rectangular portion (420) in sequence along its thickness direction; the bottom surface of the trapezoidal portion (410) is of equal width to and connected to the upper surface of the rectangular portion (420); the lower surface of the rectangular portion (420) contacts the upper surface of the pad (200); and the rectangular portion (420) is interference-fitted with a notch (311) of the groove (310).

4. The welding method for a rail vehicle according to claim 3, characterized in that: The inclined surface of the trapezoidal portion (410) is inclined inwardly at an angle between 25° and 30° along the direction from the bottom surface to the top surface of the trapezoidal portion (410), the thickness of the trapezoidal portion (410) is between 2 mm and 3 mm, and during processing of the reinforcing plate (400), the angle between the rolled fiber direction and the length direction thereof is between 45° and 135°.

5. A welding device for a rail vehicle, characterized in that: A welding method for a rail vehicle according to any one of claims 1 to 4, comprising: A wedge-shaped block (100), wherein the wedge-shaped block (100) is provided with a first inclined surface (110), and the first inclined surface (110) is gradually inclined upward along the extension direction of the groove (310); A pad (200), wherein the pad (200) is provided with a second inclined surface (210), the second inclined surface (210) cooperates with the first inclined surface (110), the wedge block (100) is suitable for driving the pad (200) to switch between a first state and a second state, in the first state, the second inclined surface (210) moves upward along the first inclined surface (110), in the second state, the second inclined surface (210) is fixed, and the vertical distance between the upper surface of the pad (200) and the upper surface of the crossbeam (300) is the thickness of the reinforcing plate (400).

6. The welding device for a rail vehicle according to claim 5, characterized in that: The wedge block (100) comprises a wedge-shaped portion (120) and an extension portion (130), wherein the wedge-shaped portion (120) is located in the groove (310), one end of the extension portion (130) is connected to the upwardly inclined end of the first inclined surface (110) of the wedge-shaped portion (120), and the other end extends upward from a notch (311) of the groove (310).

7. The welding device for a rail vehicle according to claim 6, characterized in that: The extension portion (130) comprises a groove withdrawal surface (131) and a groove entry surface (132) which are sequentially arranged along the extension direction of the groove (310); the groove withdrawal surface (131) and the groove entry surface (132) are arranged opposite to each other; the first inclined surface (110) is smoothly connected to the groove withdrawal surface (131) via a transition surface (133); and the transition surface (133) is an arc-shaped surface.

8. The welding device for a rail vehicle according to claim 5, characterized in that: The pad (200) comprises a first plate portion (220) and a second plate portion (230), wherein the first plate portion (220) is arranged on a side surface of the second plate portion (230) in a thickness direction thereof, the width of the first plate portion (220) is smaller than the width of the second plate portion (230), and the second plate portion (230) is provided with the second inclined surface (210) at both ends of the side surface opposite to the first plate portion (220).

9. The welding device for a rail vehicle according to claim 5, characterized in that: The pad (200) comprises two first plate portions (220) and a second plate portion (230), the two first plate portions (220) being respectively arranged on two side surfaces of the second plate portion (230) in a thickness direction thereof, the width of the first plate portion (220) being smaller than the width of the second plate portion (230), the length of the two first plate portions (220) being the same as the length of the second plate portion (230), and the end of each second plate portion (230) close to the pad (200) being provided with the second inclined surface (210).

10. The welding device for a rail vehicle according to claim 8 or 9, characterized in that: The two side surfaces of the first plate portion (220) in the width direction are third inclined surfaces (221), and the angle formed by the third inclined surfaces (221) and the surface of the second plate portion (230) is between 115° and 125°.

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