Traction beam structure suitable for flexible marshalling

Abstract

Compared with an existing structure, the traction beam structure suitable for flexible marshalling has the advantages that the structural form, the welding heat influence, the welding manufacturability, the production manufacturability, the material selection, the compatibility of related systems and other aspects are comprehensively considered, reasonable design is carried out, under the condition that the structural strength is guaranteed, the occupied space of the structure is reduced, and the construction cost is reduced. And the existing system interface is compatible, the flexible marshalling requirement is met, and the blank that flexible marshalling cannot be achieved due to the structure is filled.

Description

Technical Field

[0001] This invention relates to the car body system of urban rail transit vehicles, and more specifically to a traction beam structure suitable for flexible formation. Background Technology

[0002] Current urban rail transit vehicles are generally fixed formations, with 6-car formations being the most common. However, passenger capacity is dynamic, while the formation is fixed. Therefore, when passenger capacity is low, operating fixed-formation vehicles will result in energy waste. If fixed-formation short formations are coupled in pairs, it will lead to a mismatch between the vehicle doors and the platform screen doors. Summary of the Invention

[0003] To meet the needs of flexible train formation, the buffer area of ​​the traction beam is shortened by 1000mm, which is nearly 30%. Taking into account the interfaces of the bogie and other systems, the shape of the buffer zone of the traction beam is adjusted. The angle between the fitted straight line and the rail surface is about 50 degrees, while the common angle is about 20 to 40 degrees.

[0004] The aforementioned adjustments made to achieve functionality resulted in extremely harsh stress conditions for the traction beam. The shortening of the buffer zone and the increase in the shape angle made it easier for stress concentration to occur, leading to insufficient structural strength.

[0005] The purpose of this invention is to design a new traction beam structure that takes into account the existing platform screen door layout, the energy absorption requirements of the coupler, and the need to avoid occupying additional space for the bogie and coupler energy absorption. This new structure shortens the traction beam while maintaining its strength, so that it can meet the requirements of flexible train formation and has almost no impact on other systems, allowing for rapid application.

[0006] To achieve the above objectives, the present invention provides a traction beam structure suitable for flexible train formation, comprising a first upper cover plate, a second upper cover plate, a third upper cover plate, a coupler seat, a traction beam upright plate, an auxiliary traction beam upright plate, an upright plate, a first lower cover plate, a second lower cover plate, and a third lower cover plate. The welds between the first and second upper cover plates and the floor are located at the floor profile reinforcement. The coupler seat is connected to the second upper cover plate and the second lower cover plate via a plug-in structure. The first lower cover plate has a transition interface with the second lower cover plate. The first, second, and third lower cover plates are arc-shaped plates, and the arc-shaped plates are tangent to each other. The auxiliary traction beam upright plate is located between the upper and lower cover plates and is connected by welding.

[0007] Furthermore, the auxiliary traction beam upright plate extends to the welding interface area between the coupler seat and the traction beam upright plate and is bent to extend 60mm towards the coupler seat mounting surface area. This ensures that the process holes of the coupler seat are not affected, while also bearing part of the load. This area has high stress, and this structure can share the stress of the coupler seat, upper and lower cover plates and traction beam upright plate. Moreover, the bent shape can increase the rigidity of the auxiliary traction beam upright plate, which is beneficial to the stability of the overall structure.

[0008] Furthermore, the transition interface is designed with rounded corners to avoid stress concentration.

[0009] Furthermore, the first lower cover plate, the second lower cover plate, and the third lower cover plate are made of 5083-H321 material.

[0010] Furthermore, the material of the traction beam upright plate is 5083-H321.

[0011] Furthermore, the ratio of the distance between the mounting surface of the coupler seat and the junction of the first and second lower cover plates to its distance from the center of the bolster beam is 1:4.

[0012] Furthermore, the thickness ratio of the second lower cover plate to the first lower cover plate is 2:5.

[0013] Furthermore, in the weld area between the first and second upper cover plates and the floor, the first and second lower cover plates have a total of three openings, named openings a, b, and c sequentially from the coupler seat area to the bolster beam area. A portion of base material is left between the three openings, with a width of 70-80mm. Opening a uses a curved arc with a diameter of 360mm, which is larger than a conventional opening and not a traditional semi-circle, providing more welding space while ensuring strength. Opening b uses a triangle instead of a traditional rectangle, which disperses and transmits force. The stress in the area of ​​opening c is relatively small, so a conventional rectangular opening is used.

[0014] The advantages of this invention include: (1) it can meet the needs of flexible grouping;

[0015] (2) Optimize the force transmission path to reduce the space occupied by the structure while ensuring structural strength;

[0016] (3) All straight segments of the lower cover plate shape are removed and replaced with arc shapes. All arc shapes are tangent to each other. The arc radius is reasonably designed to avoid stress concentration.

[0017] (4) Add an auxiliary traction beam upright plate to share the stress of the main traction beam upright plate, the lower cover plate, and the coupler seat;

[0018] (5) Change the width of the top cover plate so that, while meeting the structural interface requirements, the weld seam with the aluminum floor is located at the rib of the floor profile, thereby improving the structural strength.

[0019] (6) Taking into account the processability of plate manufacturing, adjust the welding position of the lower cover plate and adjust the weld to a relatively low stress area;

[0020] (7) Local thickening is carried out in areas with high stress, and welding tolerances and deformation factors are taken into account. Part of the lower cover plate is merged to reduce the negative impact of welding tolerances and heat effects caused by thick plate welding on structural strength.

[0021] (8) Change the material of the lower cover plate and the traction beam upright plate to 5083-H321 to improve the structural strength;

[0022] (9) Change the T-shaped contact structure between the coupler seat and the upper and lower cover plates to a plug-in structure, and improve the structural strength by utilizing the strength of the material itself;

[0023] (10) Considering the interface compatibility of bogies and couplers, it can be applied quickly without the need for other system adaptations.

[0024] Compared to existing structures, the advantages of this invention are that it comprehensively considers structural form, welding heat effect, welding processability, production processability, material selection, and compatibility with related systems, and makes reasonable designs. While ensuring structural strength, it reduces the space occupied by the structure, is compatible with existing system interfaces, meets the requirements for flexible grouping, and fills the gap that cannot be achieved by flexible grouping due to structural reasons. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the device in operation;

[0026] Figure 2 This is a front sectional view of the device;

[0027] Figure 3 This is a bottom view of the device. Detailed Implementation

[0028] Reference Figures 1 to 3 The entire structure is mainly composed of the first upper cover plate 1, the second upper cover plate 2, the third upper cover plate 3, the coupler seat 4, the traction beam upright plate 5, the auxiliary traction beam upright plate 6, the upright plate 7, the first lower cover plate 8, the second lower cover plate 9, and the third lower cover plate 10.

[0029] The force transmission path was optimized, and all straight segments of the first lower cover plate 8, the second lower cover plate 9, and the third lower cover plate 10 were eliminated and replaced with arc shapes. The radius of the arcs was reasonably designed, and all arc shapes were tangent to each other to avoid stress concentration. After repeated verification, the shape with the least stress and the smoothest force transmission was determined. An auxiliary traction beam upright plate 6 was added to share the stress of the main traction beam upright plate 5, the upper and lower cover plates, and the coupler seat 4. In coordination with the structure of the traction beam upright plate 5 and the lower cover plate, the width of the upper cover plate was modified so that, while meeting the structural interface requirements, the weld seam to the aluminum floor was located at the rib of the floor profile, thereby improving structural strength.

[0030] Through multiple simulation analyses and considering the manufacturing process of the sheet metal, the welding position of the lower cover plate was adjusted to place the weld in a relatively low-stress area. Areas with high stress were locally thickened, and considering welding tolerances and deformation factors, some lower cover plates were merged to reduce the negative impact of welding tolerances and heat effects caused by thick plate welding on structural strength. The material of the first lower cover plate 8, the second lower cover plate 9, the third lower cover plate 10, and the traction beam upright plate 5 was changed to 5083-H321 to improve structural strength. The T-shaped contact structure between the coupler seat 4 and the upper and lower cover plates was changed to an insert structure, i.e., openings were made at the upper and lower cover plates, and the coupler seat 4 was partially inserted into the upper and lower cover plates, utilizing the inherent strength of the material to improve structural strength.

[0031] The shapes of the first lower cover plate 8, the second lower cover plate 9, and the third lower cover plate 10 are rationally designed to maximize force transmission within a limited buffer zone. Based on calculation results, after multiple optimizations, the weld positions are designed considering welding heat-affected zones, manufacturing processes, and stress distribution, satisfying both structural strength requirements and ease of manufacturing. The first lower cover plate 8, instead of the common two-plate welding, is now a single unit, reducing welding heat-affected zones. Simultaneously, its thickness is locally increased, and a transition interface with the second lower cover plate 9 is designed to avoid stress concentration. The material selected is 5083-H321.

[0032] In conventional designs, the first lower cover plate 8 is welded from two plates. Due to the heat-affected zone (HAZ) of the weld, localized strength decreases. The plates used in this patent are 30mm thick. If the conventional welding design is still employed, the weld penetration will be deep, the welding heat will be high, and welding deformation is likely. Designing the two plates as a single unit effectively avoids strength reduction and deformation. However, the large plate size and complex shape lead to manufacturing difficulties and low yield. Therefore, the junction of the first lower cover plate 8 and the second lower cover plate 9 needs adjustment, ensuring that the first lower cover plate 8 is not too large and the arc segment is not too long. Due to welding, the allowable strength at the junction of the first lower cover plate 8 and the second lower cover plate 9 is low, and the corresponding area experiences high stress, contradicting manufacturing requirements. To solve this problem, through simulation calculations and optimized design, the junction of the first lower cover plate 8 and the second lower cover plate 9 was rationally set, satisfying both strength requirements and ensuring a high yield in manufacturing. The ratio of the distance from the mounting surface of the coupler seat 4 to the junction position to its distance from the center position of the sleeper beam has been changed from the common ratio of less than 1:5 to approximately 1:4.

[0033] The second lower cover plate 9 has relatively low stress. Using 5083-H321 material allows for the use of thinner plates, contributing to weight reduction. The thickness ratio of the second lower cover plate 9 to the first lower cover plate 8 is changed from the common ratio of more than 3:5 to approximately 2:5. The opening shape and position of the first lower cover plate 8 and the second lower cover plate 9 are designed considering stress relief, weight reduction, and subsequent welding process requirements. Specifically, in the weld area between the first upper cover plate 1, the second upper cover plate 2, and the floor, the first lower cover plate 8 and the second lower cover plate 9 have a total of three openings, named openings a, b, and c sequentially from the coupler seat 4 area to the bolster beam area. A portion of the base material is left between the three openings, with a width of approximately 70-80mm. Opening a uses a 360mm diameter arc curve, larger than a conventional semi-circle, providing more welding space while ensuring strength. Opening b uses a triangle instead of a traditional rectangle to disperse and transmit force. Opening c has relatively low stress and uses a conventional rectangular opening. Through the above design, structural strength is ensured, processability is improved, and weight reduction is achieved.

[0034] The third lower cover plate 10 is thickened overall, and the material is selected as 5083-H321. The force transmission path of the traction beam upright plate 5 and the auxiliary traction beam upright plate 6 is designed according to the simulation results. Due to the shortening of the overall length of the traction beam, the coupler seat 4 needs to have part of its structure cut off to follow the shape of the lower cover plate, resulting in a loss of strength. In order to solve the negative impact caused by this, the auxiliary traction beam upright plate 6 is specifically extended in the stress concentration area of ​​the coupler seat 4 to bear part of the load. The material is selected as 5083-H321. The auxiliary traction beam upright plate 6 extends to the welding interface area between the coupler seat 4 and the traction beam upright plate 5 and is bent into shape, extending 60mm towards the coupler seat mounting surface area. This ensures that the process hole of the coupler seat 4 is not affected, while bearing part of the load. The stress in this area is relatively large. This structure can share the stress of the coupler seat 4, the upper and lower cover plates and the traction beam upright plate 5. Moreover, the bending shape can increase the stiffness of the auxiliary traction beam upright plate 6, which is beneficial to the stability of the overall structure.

[0035] The first upper cover plate 1 and the second upper cover plate 2 are widened outward to ensure the welding and tooling space for the auxiliary traction beam upright plate 6. At the same time, since the traction beam structure of this patent has good strength, no additional reinforcement structure is needed on the inner side of the traction beam. Therefore, the inner sides of the first upper cover plate 1 and the second upper cover plate 2 can be tightened to reduce weight. After the width of the upper cover plate is designed according to the above idea, the relationship with the floor is then considered and finely adjusted so that the weld seam with the floor is located at the floor profile rib. The coupler seat 4 is connected to the second upper cover plate 2 and the second lower cover plate 9 through a plug-in structure.

Claims

1. A traction beam structure suitable for flexible formation, characterized in that, The system includes a first upper cover plate, a second upper cover plate, a third upper cover plate, a coupler seat, a traction beam upright plate, an auxiliary traction beam upright plate, an upright plate, a first lower cover plate, a second lower cover plate, and a third lower cover plate. The welds between the first and second upper cover plates and the floor are located at the floor profile reinforcement. The coupler seat is connected to the second upper cover plate and the second lower cover plate via a plug-in structure. The first lower cover plate has a transition interface with the second lower cover plate. The first, second, and third lower cover plates are all arc-shaped plates, and the arc-shaped plates are tangent to each other. The auxiliary traction beam upright plate is located between the upper and lower cover plates and is connected by welding.

2. A traction beam structure suitable for flexible formation according to claim 1, characterized in that, The auxiliary traction beam upright plate extends to the welding interface area between the coupler seat and the traction beam upright plate and is bent to extend 60mm towards the coupler seat mounting surface area. This ensures that the process holes of the coupler seat are not affected, while also bearing part of the load. This area has high stress, and this structure can share the stress of the coupler seat, upper and lower cover plates and traction beam upright plate. In addition, the bent shape can increase the rigidity of the auxiliary traction beam upright plate, which is beneficial to the stability of the overall structure.

3. A traction beam structure suitable for flexible formation according to claim 1, characterized in that, The transition interface is designed with rounded corners to avoid stress concentration.

4. A traction beam structure suitable for flexible formation according to claim 1, characterized in that, The first, second, and third lower cover plates are made of 5083-H321 material.

5. A traction beam structure suitable for flexible formation according to claim 1, characterized in that, The material of the traction beam upright plate is 5083-H321.

6. A traction beam structure suitable for flexible formation according to claim 2, characterized in that, The ratio of the distance between the mounting surface of the coupler seat and the junction of the first and second lower cover plates to its distance from the center of the sleeper beam is 1:

4.

7. A traction beam structure suitable for flexible formation according to claim 1, characterized in that, The thickness ratio of the second lower cover plate to the first lower cover plate is 2:

5.

8. A traction beam structure suitable for flexible formation according to claim 1, characterized in that, In the weld area between the first and second upper cover plates and the floor, the first and second lower cover plates have a total of three openings, named openings a, b, and c from the coupler seat area to the bolster beam area. There is a gap of base material between the three openings, with a width of 70-80mm. Opening a adopts a curved arc with a diameter of 360mm, opening b adopts a triangle, and the force is distributed and transmitted through the triangle. The stress in the area of ​​opening c is relatively small, and a conventional rectangular opening is used.

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