Welding methods and sheet metal for the maintenance of enclosed box-type structures of rail vehicles

Abstract

This invention relates to the field of rail vehicles, providing a maintenance welding method and sheet metal for a closed box-type structure of a rail vehicle. The maintenance welding method for the closed box-type structure of a rail vehicle includes: arranging a reinforcing plate on the side of a side beam facing a crossbeam, with a gap between the joint of the reinforcing plate and the crossbeam; moving a pad along the gap using an installation rod until the pad is inserted from the open space into the closed space; rotating the pad from the side beam towards the crossbeam within the closed space until the first part of the pad contacts the joint of the crossbeam; moving the pad towards the side beam using the installation rod until the second part of the pad contacts the surface of the side beam; separating the installation rod from the pad; and welding the through groove formed by the joint of the reinforcing plate, the pad, and the crossbeam. Through the cooperation of the installation rod and the pad, a quick and controllable pad installation effect is achieved, ensuring the formation of the weld back while controlling the installation process. This also forms a process method for rapid repair of reinforcing plates under maintenance conditions, improving welding quality.

Description

Technical Field

[0001] This invention relates to the field of rail vehicles, and provides a method for welding and maintenance of enclosed box-shaped structures for rail vehicles, as well as the corresponding sheet metal. Background Technology

[0002] The repair of side beam reinforcement plates presents challenges such as limited installation space for undercarriage welding pads, and uncontrollable pad position and condition after installation. As high-speed train speeds continue to increase and operating ranges expand, the vehicles experience increasingly harsher service conditions, including impacts, fatigue, and corrosion. To extend service life and ensure operational safety, reinforcement plates are added to the original car body during maintenance. Since the vehicle is already assembled during maintenance, the processing and welding of the reinforcement plate joints must be completed undercarriage.

[0003] Welding between the reinforcing plate and the original vehicle body usually involves adding a welding backing plate to ensure the quality of the weld penetration. Under vehicle maintenance conditions, especially in vehicle cavity areas, there are quality risks such as insufficient space for installation of the welding backing plate, improper installation of the backing plate, or uncontrolled loss of the backing plate into the cavity after installation, causing abnormal noises in the vehicle. Therefore, the installation of the backing plate under maintenance conditions is extremely difficult. Summary of the Invention

[0004] This invention provides a maintenance welding method and plate for a closed box-type structure of a rail vehicle, which addresses one of the deficiencies in related technologies. By cooperating with the mounting rod and the pad, the method achieves quick and easy controllable pad installation, ensuring the formation of the weld back while controlling the installation process. It also forms a process method for rapid repair of the reinforcing plate under maintenance conditions, thereby improving welding quality.

[0005] This invention provides a maintenance welding method for a closed box-type structure of a rail vehicle. The closed box-type structure includes side beams and cross beams. The side beams and cross beams are arranged opposite to and perpendicular to each other. The cross beams divide the space into a closed space and an open space along the extension direction of the side beams.

[0006] The method includes:

[0007] A reinforcing plate is arranged on one side of the side beam facing the crossbeam, and there is a gap between the joint of the reinforcing plate and the crossbeam;

[0008] The mounting rod drives the pad to move along the gap until the pad is inserted from the open space into the closed space;

[0009] The pad is rotated from the side beam toward the cross beam within the enclosed space until the first plate of the pad contacts the joint of the cross beam;

[0010] The mounting rod drives the pad to move toward the side beam until the second plate portion of the pad contacts the surface of the side beam.

[0011] Separate the mounting rod from the pad;

[0012] The joints of the reinforcing plate, the pad, and the crossbeam are welded together.

[0013] According to one embodiment of the present invention, before separating the mounting rod from the pad, the method further includes:

[0014] The joint between the pad, the reinforcing plate, and the crossbeam is connected by tack welding, wherein the tack weld is located between the end of the pad along its length and the mounting rod.

[0015] According to one embodiment of the present invention, before the step of moving the pad along the gap via the mounting rod, the method further includes:

[0016] The joint of the crossbeam is beveled, and a gap is formed between the surface of the bevel and the surface of the reinforcing plate. The width of the gap gradually increases along the direction from the closed space to the open space.

[0017] According to one embodiment of the present invention, the bevel includes an inclined surface and an arc surface, the arc surface being a surface that gradually concaves away from the reinforcing plate along the direction from the closed space to the open space, the arc surface and the inclined surface being smoothly connected sequentially along the direction from the closed space to the open space, and the angle of the bevel is between 25° and 30°.

[0018] According to one embodiment of the present invention, the through groove formed by the joint of the reinforcing plate, the pad plate and the crossbeam is welded in three layers and three passes.

[0019] According to one embodiment of the present invention, the mounting rod is a deformable plastic rod body, adapted to switch between a first state and a second state. In the first state, the mounting rod is connected to the pad, and in the second state, the mounting rod deforms and detaches from the pad.

[0020] This invention also provides a maintenance welding plate for a closed box-type structure of a rail vehicle, applied to the maintenance welding method for the closed box-type structure of a rail vehicle as described above, including:

[0021] A first plate portion and a second plate portion are sequentially connected along the width direction of the pad;

[0022] The first plate portion is adapted to contact the joint of the crossbeam;

[0023] The second plate portion is adapted to contact the reinforcing plate;

[0024] The thickness of the pad is less than the gap between the joint between the reinforcing plate and the crossbeam;

[0025] The first plate portion is provided with a through hole extending along the thickness direction of the pad;

[0026] The through hole is adapted for detachable connection with the mounting rod.

[0027] According to one embodiment of the present invention, the second plate portion contacts the joint of the crossbeam, and the inner diameter of the through hole gradually decreases along the direction from the open space to the closed space.

[0028] According to one embodiment of the present invention, the minimum diameter of the through hole is 1.5 to 2.5 times the diameter of the mounting rod.

[0029] According to one embodiment of the present invention, the pad has a recess on the surface facing the crossbeam, so that the thickness of the second plate portion is greater than the thickness of the first plate portion.

[0030] The above-described one or more technical solutions in the embodiments of the present invention have at least one of the following technical effects:

[0031] The maintenance welding method for the enclosed box-type structure of a rail vehicle provided in this embodiment of the invention involves the following steps: After the reinforcing plate is installed on the side beam, a gap is formed between the joint of the reinforcing plate and the crossbeam. A pad is then inserted from the open space into the closed space through the gap using an installation rod. The position of the pad relative to the joint of the reinforcing plate and the crossbeam is then adjusted. Specifically, the pad is rotated from the side beam position to the crossbeam position. After the first plate of the pad rests on the joint surface of the crossbeam, the pad is pulled towards the side beam using the installation rod, causing the second plate of the pad to abut against the reinforcing plate. After the position of the pad is adjusted, a groove-like structure is formed between the joint of the reinforcing plate, the pad, and the crossbeam. Finally, the installation rod is removed, and the groove is welded, thus completing the maintenance welding of the enclosed box-type structure of the rail vehicle.

[0032] This invention, based on the maintenance and repair conditions of the reinforcing plate structure of rail vehicles, designs a welding method adapted to the repair conditions. Through the cooperation of the mounting rod and the backing plate, it achieves quick and easy controllable backing plate installation, ensuring the formation of the weld back while controlling the installation process. At the same time, it forms a process method for rapid repair of reinforcing plates under maintenance conditions, improving welding quality. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0034] Figure 1 This is a structural diagram of the original enclosed box-shaped structure of existing rail vehicles;

[0035] Figure 2 This is a schematic diagram of the structure of a closed box-type rail vehicle after maintenance, based on existing technology.

[0036] Figure 3 This is a structural diagram of the maintenance status of a closed box-type structure for existing rail vehicles.

[0037] Figure 4 yes Figure 3 A magnified view of part A;

[0038] Figure 5 This is a schematic diagram of a pre-existing closed box-type rail vehicle structure where the shim plate is not properly installed during maintenance welding.

[0039] Figure 6 This is a schematic diagram of the structure of a closed box-type rail vehicle where a backing plate is left in the enclosed space during maintenance welding.

[0040] Figure 7a This is one of the structural schematic diagrams of the bevel design process for the joint of the crossbeam provided in the embodiment of the present invention;

[0041] Figure 7b This is the second structural schematic diagram of the bevel design process for the joint of the crossbeam provided in this embodiment of the invention;

[0042] Figure 7c This is the third structural schematic diagram of the bevel design process for the joint of the crossbeam provided in this embodiment of the invention;

[0043] Figure 8a This is one of the structural schematic diagrams of the pad provided in the embodiment of the present invention;

[0044] Figure 8b This is a second schematic diagram of the structure of the pad provided in an embodiment of the present invention;

[0045] Figure 8c yes Figure 8a A magnified view of part I;

[0046] Figure 9a This is one of the structural schematic diagrams of the connection between the pad and the mounting rod provided in the embodiments of the present invention;

[0047] Figure 9b This is a second schematic diagram of the connection between the pad and the mounting rod provided in an embodiment of the present invention;

[0048] Figure 10 This is a flowchart of the maintenance and welding method for the enclosed box-shaped structure of a rail vehicle provided in an embodiment of the present invention;

[0049] Figure 11a This is one of the structural schematic diagrams of the process of placing the pad into a closed space according to an embodiment of the present invention;

[0050] Figure 11b This is the second schematic diagram of the process of placing the pad into the enclosed space according to an embodiment of the present invention;

[0051] Figure 11c This is the third schematic diagram of the process of placing the pad into the enclosed space according to the embodiment of the present invention;

[0052] Figure 11d This is the fourth structural schematic diagram of the process of placing the pad into the enclosed space according to the embodiment of the present invention;

[0053] Figure 12a This is one of the structural schematic diagrams of the pad position adjustment process provided in the embodiment of the present invention;

[0054] Figure 12b This is the second structural schematic diagram of the pad position adjustment process provided in the embodiment of the present invention;

[0055] Figure 13a This is one of the structural schematic diagrams of the pad positioning process provided in the embodiment of the present invention;

[0056] Figure 13b This is the second structural schematic diagram of the pad positioning process provided in the embodiment of the present invention;

[0057] Figure 14a This is one of the structural schematic diagrams of the installation rod removal provided in the embodiments of the present invention;

[0058] Figure 14b This is the second schematic diagram of the structure for removing the mounting rod provided in this embodiment of the invention;

[0059] Figure 15 This is a macroscopic metallographic image of the welded position after maintenance welding of the closed box-shaped structure of a rail vehicle provided in an embodiment of the present invention.

[0060] Figure label:

[0061] 110. Side beam; 120. Crossbeam; 121. Bevel; 122. Inclined surface; 123. Curved surface; 130. Enclosed space; 140. Open space;

[0062] 200. Reinforcing plate;

[0063] 300, pad; 310, first plate portion; 311, through hole; 320, second plate portion; 330, recess;

[0064] 400. Mounting rod; 410. Bent section. Detailed Implementation

[0065] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and should not be construed as limiting the scope of the invention.

[0066] In the description of the embodiments of the present invention, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of the present invention. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0067] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention based on the specific circumstances.

[0068] In embodiments of the present invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0069] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0070] The original enclosed box-type structure of the rail vehicle, such as Figure 1 As shown, the structure after overhaul of the existing enclosed box-type structure is as follows: Figure 2 As shown, the original weld (weld 1) needs to be removed from the original closed box-type structure of the rail vehicle, and a reinforcing plate 200 needs to be added. The welding structure of the reinforcing plate 200 is a new weld (weld 2) formed by a T-BW joint. To ensure the welding quality, a permanent backing plate 300 needs to be added before welding weld 2.

[0071] An analysis of the welding operation space for the 200mm reinforced plate welding structure was conducted, considering that the vehicle was in a maintenance state. Figure 3 As shown, the upper part of the original enclosed box-shaped structure of the vehicle's crossbeam 120 base material is a closed space 130, where welding torches, tools, etc., cannot be operated. The lower part of the original enclosed box-shaped structure of the vehicle's crossbeam 120 base material is an open space 140, such as... Figure 4 As shown, the installation and welding of the pad 300 are carried out in the lower open space 140.

[0072] Therefore, the following problems exist when using conventional welding pads (300mm) for maintenance welding operations on existing enclosed box-type structures:

[0073] 1. The 300mm pad cannot be properly placed into the enclosed 130mm space;

[0074] 2. For example Figure 5 As shown, the pad 300 cannot be installed in place after being placed into the enclosed space 130, and the pad 300 cannot be tightly attached to the reinforcing plate 200 and the crossbeam 120 base material.

[0075] 3. For example Figure 6 As shown, the position of the pad 300 after it is placed in the enclosed space 130 is uncontrollable, and it is easy to fall into the enclosed space 130, causing abnormal vehicle operation.

[0076] This invention provides a maintenance welding method for a closed box-type structure of a rail vehicle. The closed box-type structure includes side beams 110 and cross beams 120. The side beams 110 and cross beams 120 are opposite to and perpendicular to each other. The cross beams 120 divide the space into a closed space 130 and an open space 140 along the extension direction of the side beams 110. The method includes:

[0077] The reinforcing plate 200 is arranged on the side of the side beam 110 facing the cross beam 120, and there is a gap between the joint of the reinforcing plate 200 and the cross beam 120.

[0078] The mounting rod 400 drives the pad 300 to move along the gap until the pad 300 is inserted from the open space 140 into the closed space 130.

[0079] Rotate the pad 300 from the side beam 110 toward the cross beam 120 within the enclosed space 130 until the first plate portion 310 of the pad 300 contacts the joint of the cross beam 120.

[0080] The mounting rod 400 drives the pad 300 to move toward the side beam 110 until the second plate portion 320 of the pad 300 contacts the surface of the side beam 110.

[0081] Separate the mounting rod 400 from the pad 300;

[0082] Weld the joints of the reinforcing plate 200, the pad plate 300 and the crossbeam 120.

[0083] The maintenance welding method for the enclosed box-type structure of a rail vehicle provided in this embodiment of the invention involves, after the reinforcing plate 200 is installed on the side beam 110, a gap is formed between the joint of the reinforcing plate 200 and the crossbeam 120. The mounting rod 400 is used to insert the pad 300 from the open space 140 into the enclosed space 130 through the gap. Then, the position of the pad 300 relative to the joint of the reinforcing plate 200 and the crossbeam 120 is adjusted. Specifically, the pad 300 is rotated from the side beam 110 position to the crossbeam 120 position. After the first plate 310 of the 00 rests on the joint surface of the crossbeam 120, the pad 300 is pulled towards the side beam 110 by the mounting rod 400, so that the second plate 320 of the pad 300 abuts against the reinforcing plate 200. After the position of the pad 300 is adjusted, a structure similar to a through groove is formed between the reinforcing plate 200, the pad 300 and the joint of the crossbeam 120. Finally, the mounting rod 400 is removed and the through groove is welded, thus completing the maintenance welding of the closed box structure of the rail vehicle.

[0084] Based on the maintenance and repair conditions of the reinforcing plate 200 structure of rail vehicles, this invention designs a welding method adapted to the repair conditions. Through the cooperation of the mounting rod 400 and the pad 300, the installation effect of the pad 300 is achieved quickly, conveniently and controllably, ensuring the formation of the back of the weld while controlling the installation process. At the same time, it forms a process method for rapid repair of the reinforcing plate 200 under maintenance conditions, improving the welding quality.

[0085] According to one embodiment of the present invention, before separating the mounting rod 400 from the pad 300, the method further includes:

[0086] The joints of the pad 300, the reinforcing plate 200, and the crossbeam 120 are connected by tack welding. The tack welding points are located between the end of the pad 300 along its length and the mounting rod 400.

[0087] In this embodiment, after the pad 300 is positioned within the enclosed space 130, it can be positioned between the reinforcing plate 200 and the crossbeam 120 to prevent displacement of the pad 300 during the removal of the mounting rod 400 when it is separated from the pad 300. Positioning is achieved using tack welding, with the weld points located between the end of the pad 300 and the mounting rod 400 closest to that end. In other words, the pad 300 can be welded and positioned at both ends along its length before the joint between the reinforcing plate 200 and the crossbeam 120. After removing the mounting rod 400, the entire through-slot is then welded.

[0088] According to one embodiment of the present invention, before the pad 300 is moved along the gap by the mounting rod 400, the following steps are further included:

[0089] The joint of the crossbeam 120 is beveled 121, and a gap is formed between the surface of the bevel 121 and the surface of the reinforcing plate 200. The width of the gap gradually increases along the direction from the closed space 130 to the open space 140.

[0090] In this embodiment, before installing the pad 300, the joint of the crossbeam 120 is first processed into a bevel 121 suitable for the installation of the pad 300. The surface of the bevel 121 is the joint end face of the crossbeam 120, and the space between the joint end face and the side of the reinforcing plate 200 is the gap that the pad 300 passes through when entering the closed space 130. In order to improve the reliability of the installation rod 400 in controlling the movement and installation of the pad 300, and to ensure the quality of welding penetration, the bevel 121 is designed as an flared shape from the closed space 130 to the open space 140, that is, the through groove enclosed by the joint of the reinforcing plate 200, the pad 300 and the crossbeam 120 is designed as a flared shape.

[0091] According to one embodiment of the present invention, the bevel 121 includes an inclined surface 122 and an arc surface 123. The arc surface 123 is a surface that gradually concaves 330 away from the reinforcing plate 200 along the direction from the closed space 130 to the open space 140. The arc surface 123 and the inclined surface 122 are smoothly connected in sequence along the direction from the closed space 130 to the open space 140. The angle of the bevel 121 is between 25° and 30°.

[0092] In this embodiment, the position of the bevel 121 near the enclosed space 130 is the root of the bevel 121, and the position of the bevel 121 near the open space 140 is the bottom of the bevel 121. The moving direction of the pad 300 at the bevel 121 is from the bottom of the bevel 121 to the root of the bevel 121. The bevel 121 smoothly transitions from the root to the bottom through the arc surface 123 and the inclined surface 122 in sequence. The angle of the bevel 121 is the angle formed by the inclined surface 122 and the surface of the reinforcing plate 200.

[0093] In this embodiment, the bevel 121 is designed to accommodate the welding of the reinforcing plate 200 under maintenance conditions. The design process of the bevel 121 as a new weld (weld 2) is as follows: Figure 7a , Figure 7b and Figure 7c As shown.

[0094] The joint of the conventional crossbeam 120 and the reinforcing plate 200 form a T-shaped butt weld, such as Figure 7a As shown, the bevel 121 is an HV connector with an angle of 55°~60° and a small root gap of 0~2mm. The pad 300 cannot pass through the root gap to enter the enclosed space 130 for installation.

[0095] To accommodate weld welding under maintenance conditions, the installation space for the backing plate 300 is increased, and the gap of the bevel 121 is enlarged, such as... Figure 7b As shown, however, the increased gap at bevel 121 further increased the amount of weld filler.

[0096] Further optimization of the bevel 121 form, such as... Figure 7c As shown, the bevel 121 is the final determined J-shaped small-fill, large-gap form. The bottom of the bevel 121 is open and smooth, reducing the welding risk of incomplete fusion at the root of the crossbeam 120 joint. The root gap of the bevel 121 is relatively large, and the width b of the root gap is designed according to the thickness of the backing plate 300. Generally, it is increased by 0~1mm based on the thickness t3 of the backing plate 300. Taking the most common 4mm thick backing plate 300 as an example, the width b of the root of the bevel 121 is 4mm~5mm.

[0097] The bevel angle of bevel 121 is relatively small, generally 25°~30°, resulting in a small amount of weld filler and minimal welding deformation. Taking the joint thickness t2=12mm of the crossbeam 120 as an example, compared to... Figure 7b The weld shown, Figure 7c The number of welding layers was reduced by 50%, from 3 layers and 6 passes to 3 layers and 3 passes, and the welding filler volume was reduced by 23%, from 280.5 mm² to 215.7 mm².

[0098] Figure 7b and Figure 7c The comparison of the two connector types is shown in Table 1 below.

[0099] Table 1

[0100]

[0101] According to one embodiment of the present invention, the through groove formed by the joint of the reinforcing plate 200, the pad plate 300 and the crossbeam 120 is welded by three layers and three passes of welding.

[0102] In this embodiment, the bevel angle 121 is relatively small, generally 25~30°, resulting in a small weld filler and minimal weld deformation. Taking the joint thickness t2=12mm of the crossbeam 120 as an example, compared to... Figure 7b The weld shown, Figure 7c The number of welding layers was reduced by 50%, from 3 layers and 6 passes to 3 layers and 3 passes, and the welding filler volume was reduced by 23%, from 280.5 mm² to 215.7 mm².

[0103] According to one embodiment of the present invention, the mounting rod 400 is a deformable plastic rod body, which is suitable for switching between a first state and a second state. In the first state, the mounting rod 400 is connected to the pad 300, and in the second state, the mounting rod 400 deforms and detaches from the pad 300.

[0104] In this embodiment, to control the specific position of the pad 300 during installation, an installation rod 400 is used to connect and control the pad 300 during installation. For example... Figure 9a and Figure 9b As shown, the mounting rod 400 is generally made of a variable plastic material, and aluminum alloy welding wire commonly used in welding manufacturing sites can be used as the mounting rod 400.

[0105] In this embodiment, the side beam 110 is arranged vertically, and the cross beam 120 is arranged horizontally. Therefore, the enclosed space 130 is above the cross beam 120, and the open space 140 is below the cross beam 120. The length direction of the pad 300 is its extending direction, and the width direction of the pad 300 is the direction in which it connects the side beam 110 and the cross beam 120.

[0106] like Figure 10As shown, the installation and welding method of pad 300 is divided into 5 steps: Step 1: Bevel 121 preparation; Step 2: Pad 300 controlled placement into enclosed space 130; Step 3: Pad 300 position adjustment; Step 4: Pad 300 fixing and installation rod 400 removal; Step 5: Joint welding.

[0107] (1) Preparation of bevel 121: In order to realize the installation of backing plate 300 and the small filling amount welding of the joint, according to Figure 7c Prepare bevel 121 according to Table 1.

[0108] (2) Place the 300mm pad into the enclosed space 130mm: as shown Figure 11a As shown, place the pad 300 along the bottom side of the bevel 121 below the root of the bevel 121, as follows. Figure 11b As shown, the mounting rod 400 connects to the pad 300 and guides the movement of the pad 300, controlling the attitude of the pad 300 so that the pad 300 rotates towards the location of the reinforcing plate 200 until the width direction of the pad 300 extends vertically. Figure 11c and 11d As shown, the mounting rod 400 is used to move the pad 300 upward past the root of the bevel 121, and stops when the pad 300 moves to be flush with the root of the bevel 121.

[0109] (3) Adjustment of the 300mm position of the pad: such as Figure 12a As shown, after the pad 300 is placed in the enclosed space 130, it is controlled to automatically rotate towards the position of the crossbeam 120 in a vertical state. Finally, the first plate part 310 of the pad 300 contacts the crossbeam 120, and the pad 300 is in a horizontal state. Figure 12b As shown, the mounting rod 400 is used to move the pad 300 closer to the position of the reinforcing plate 200, so that the second plate portion 320 of the pad 300 is closely attached to the reinforcing plate 200.

[0110] (4) Fixing the pad 300 and removing the mounting rod 400: After the pad 300 is moved to a suitable position, the welded joint consisting of the pad 300, the crossbeam 120 joint, and the reinforcing plate 200 is fixed by tack welding, such as... Figure 13a and 13b As shown, the tack weld is located between the ends of the mounting rod 400 and the pad 300, at a distance s = 1 / 2f from the end position. Figure 14a and Figure 14b As shown, after the pad 300 is positioned, the mounting rod 400 is pulled down. Because the material of the mounting rod 400 is relatively soft (usually aluminum alloy welding wire used on site), after being pulled down, the end of the mounting rod 400 changes from a right-angle bend to an obtuse-angle bend because the pad 300 is fixed. At this time, the mounting rod 400 can be removed from the pad 300.

[0111] (5) Welding of the joint: After the installation rod 400 is removed, the joint is welded using the 3-layer, 3-pass welding process shown in Table 1. Taking the aluminum plate with a thickness of t2=12mm as the crossbeam 120 as an example, the macroscopic metallographic structure of the joint after welding is as follows: Figure 15 As shown.

[0112] like Figure 8a , Figure 8b and Figure 8c As shown, this embodiment of the invention also provides a maintenance welding plate for a closed box-type structure of a rail vehicle, which is applied to the maintenance welding method for the closed box-type structure of a rail vehicle as described in the above embodiment. It includes a first plate portion 310 and a second plate portion 320 connected sequentially along the width direction of the pad 300. The first plate portion 310 is adapted to contact the joint of the crossbeam 120, and the second plate portion 320 is adapted to contact the reinforcing plate 200. The thickness of the pad 300 is less than the gap between the joint of the reinforcing plate 200 and the crossbeam 120. The first plate portion 310 is provided with a through hole 311 extending along the thickness direction of the pad 300. The through hole 311 is adapted to be detachably connected to the mounting rod 400.

[0113] The maintenance welding plate for the enclosed box-type structure of a rail vehicle in this embodiment of the invention is divided into a first plate portion 310 and a second plate portion 320 in the width direction. The second plate portion 320 has a through hole 311 for detachable connection of the mounting rod 400, thereby facilitating the installation of the pad 300 and the pad 300 itself. The thickness of the pad 300 is less than the width of the gap, ensuring that the pad 300 can smoothly enter the enclosed space 130. Under the repair conditions of the reinforcing plate 200, considering the design requirements of the welding bevel 121, the control of the joint gap is increased, and the bevel 121 gap is designed according to the thickness of the pad 300. This invention designs a quick-installation, convenient, and controllable welding pad 300, which can ensure the formation of the weld back while controlling the installation process. Combined with the installation and welding process of the pad 300, the feasibility of the welding process is guaranteed, and the welding quality is controlled and reliable.

[0114] In this embodiment, a plurality of through holes 311 are provided on the second plate 320, and the plurality of through holes 311 are arranged sequentially along the length of the body of the pad 300. Each through hole 311 is connected to a mounting rod 400.

[0115] According to one embodiment of the present invention, the second plate portion 320 contacts the joint of the crossbeam 120, and the inner diameter of the through hole 311 gradually decreases along the direction from the open space 140 to the closed space 130.

[0116] In this embodiment, the through hole 311 penetrates the second plate portion 320 along the thickness direction of the pad 300. The bent section 410 of the mounting rod 400 passes through the through hole 311 from one side of the second plate portion 320 to the other side of the second plate portion 320. The diameter of the through hole 311 gradually decreases along the passing direction of the mounting rod 400, thereby forming a tapered through hole 311. When the second plate portion 320 contacts the joint surface of the crossbeam 120, the pad 300 is in a horizontal state. At this time, the tapered through hole 311 is a through hole 311 whose diameter gradually decreases from bottom to top.

[0117] To control the specific position of the pad 300 during installation, the pad 300 is used in conjunction with an installation rod 400 inserted into the through hole 311. The tapered through hole 311 allows the installation rod 400 to maintain a certain range of rotation within the through hole 311 after insertion, thus facilitating the tilting and posture adjustment of the pad 300 within a certain angle, and making it easier to control the movement and installation of the pad 300.

[0118] According to one embodiment of the present invention, the minimum diameter of the through hole 311 is 1.5 to 2.5 times the diameter of the mounting rod 400.

[0119] In this embodiment, the key dimensions of the pad 300 and the mounting rod 400 are the diameter d1 of the through hole 311, the vertical distance n of the through hole 311 from the side of the second plate portion 320 extending along its length direction, and the diameter d2 of the mounting rod 400, wherein the diameter d2 of the mounting rod 400 can be 1.2mm or 1.6mm.

[0120] To ensure that the mounting rod 400 can effectively control the pad 300 after it passes through the through hole 311, and to satisfy the controlled flipping of the pad 300 subsequently, the diameter d1 of the through hole 311 of the pad 300 is twice the diameter d2 of the mounting rod 400, generally 2.4mm or 3.2mm; the through hole 311 of the pad 300 adopts a tapered hole design, and the maximum diameter side of the tapered through hole 311 is at the recess 330 of the pad 300; the vertical distance n from the through hole 311 to the side of the second plate 320 extending along its length is also twice the diameter d2 of the mounting rod 400, generally 2.4mm or 3.2mm.

[0121] According to one embodiment of the present invention, the pad 300 body has a recess 330 on the surface facing the crossbeam 120, so that the thickness of the second plate portion 320 is greater than the thickness of the first plate portion 310.

[0122] In this embodiment, the pad 300 adopts a side recess 330. The recess 330 divides the pad 300 into a thicker second plate portion 320 and a thinner first plate portion 310. When the pad 300 enters the enclosed space 130 in a vertical state, the side of the first plate portion 310 that is flush with the second plate portion 320 is close to the reinforcing plate 200, while the side of the first plate portion 310 that is misaligned with the second plate portion 320 due to the recess 330 is close to the crossbeam 120. Therefore, the first plate portion 310... Compared to the first plate 310, the center of gravity of the second plate 320 is biased towards the crossbeam 120. The second plate 320 is located above the first plate 310, so the upper part of the pad 300 is heavier, which is conducive to the automatic flipping of the pad 300 in this state. It can automatically complete the action of rotating towards the position of the crossbeam 120. Finally, the pad 300 is in a flat state. The position of the pad 300 is moved by the mounting rod 400, so that the first plate 310 of the pad 300 is closely attached to the reinforcing plate 200.

[0123] In addition, when the backing plate 300 is in a horizontal state within the enclosed space 130, the recess 330 on the backing plate 300 is set in conjunction with the bevel 121 and is located above the root of the bevel 121, which can also ensure the formation of the back of the weld.

[0124] The dimensions of the pad 300 and control bar are shown in Table 2 below, and are determined by the thickness of the crossbeam 120 at the part to be welded on site.

[0125] Table 2

[0126]

[0127] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for welding and maintenance of a closed box-type structure for rail vehicles, characterized in that, The enclosed box structure includes: side beams (110) and cross beams (120), the side beams (110) and the cross beams (120) are opposite to each other and perpendicular to each other, and the cross beams (120) divide the space into enclosed space (130) and open space (140) along the extension direction of the side beams (110). The method includes: A reinforcing plate (200) is arranged on one side of the side beam (110) facing the cross beam (120), and there is a gap between the joint of the reinforcing plate (200) and the cross beam (120); The pad (300) is moved along the gap by the mounting rod (400) until the pad (300) is inserted from the open space (140) into the closed space (130). The pad (300) is rotated within the enclosed space (130) from the side beam (110) toward the cross beam (120) until the first plate portion (310) of the pad (300) contacts the joint of the cross beam (120); The mounting rod (400) drives the pad (300) to move toward the side beam (110) until the second plate portion (320) of the pad (300) contacts the surface of the side beam (110); Separate the mounting rod (400) from the pad (300); The joints of the reinforcing plate (200), the pad plate (300), and the crossbeam (120) are welded together.

2. The maintenance and welding method for the enclosed box-type structure of a rail vehicle according to claim 1, characterized in that, Before separating the mounting rod (400) from the pad (300), the method further includes: The joints of the pad (300) with the reinforcing plate (200) and the crossbeam (120) are connected by tack welding, and the tack welding point is located between the end of the pad (300) along its length direction and the mounting rod (400).

3. The maintenance and welding method for the enclosed box-type structure of a rail vehicle according to claim 1 or 2, characterized in that, Before the pad (300) is moved along the gap by the mounting rod (400), the following is also included: The joint of the crossbeam (120) is beveled (121), and the gap is formed between the surface of the bevel (121) and the surface of the reinforcing plate (200). The width of the gap gradually increases along the direction from the closed space (130) to the open space (140).

4. The maintenance and welding method for the enclosed box-type structure of a rail vehicle according to claim 3, characterized in that, The bevel (121) includes an inclined surface (122) and an arc surface (123). The arc surface (123) is a surface that gradually recesses (330) away from the reinforcing plate (200) along the direction from the closed space (130) to the open space (140). The arc surface (123) and the inclined surface (122) are smoothly connected in sequence along the direction from the closed space (130) to the open space (140). The angle of the bevel (121) is between 25° and 30°.

5. The maintenance and welding method for the enclosed box-type structure of a rail vehicle according to claim 4, characterized in that, The through groove formed by the joint of the reinforcing plate (200), the pad plate (300) and the crossbeam (120) is welded in 3 layers and 3 passes.

6. The maintenance and welding method for the enclosed box-type structure of a rail vehicle according to claim 1, characterized in that, The mounting rod (400) is a deformable plastic rod body, which is suitable for switching between a first state and a second state. In the first state, the mounting rod (400) is connected to the pad (300). In the second state, the mounting rod (400) deforms and detaches from the pad (300).

7. A maintenance welding plate for a closed box-type structure of a rail vehicle, characterized in that, The maintenance welding method applied to the enclosed box-type structure of a rail vehicle according to any one of claims 1 to 6 includes: A first plate portion (310) and a second plate portion (320) are sequentially connected along the width direction of the pad (300). The first plate portion (310) is adapted to contact the joint of the crossbeam (120); The second plate portion (320) is adapted to contact the reinforcing plate (200); The thickness of the pad (300) is less than the gap between the joint of the reinforcing plate (200) and the crossbeam (120); The first plate portion (310) is provided with a through hole (311) extending along the thickness direction of the pad (300). The through hole (311) is adapted to be detachably connected to the mounting rod (400).

8. The maintenance welding plate for the enclosed box-type structure of rail vehicles according to claim 7, characterized in that, The second plate portion (320) contacts the joint of the crossbeam (120), and the inner diameter of the through hole (311) gradually decreases along the direction from the open space (140) to the closed space (130).

9. The maintenance welding plate for the enclosed box-type structure of rail vehicles according to claim 8, characterized in that, The minimum diameter of the through hole (311) is 1.5 to 2.5 times the diameter of the mounting rod (400).

10. The maintenance welding plate for the enclosed box-type structure of a rail vehicle according to any one of claims 7 to 9, characterized in that, The pad (300) has a recess (330) on the surface facing the crossbeam (120) so that the thickness of the second plate portion (320) is greater than the thickness of the first plate portion (310).

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