Tubular element for a vehicle, body and vehicle

Abstract

The application discloses a tubular part for a vehicle, a vehicle body and a vehicle. The tubular part for the vehicle comprises a transition pipe section and at least two equal-thickness pipe sections. The transition pipe section and the equal-thickness pipe sections are alternately arranged and integrally formed. The thicknesses of any two adjacent equal-thickness pipe sections are different. The tubular part for the vehicle provided by the application has the advantages of high strength, light weight and low cost.

Description

Technical Field

[0001] This disclosure relates to the field of vehicle technology, specifically to a tubular component for vehicles, a vehicle body, and a vehicle. Background Technology

[0002] In vehicle assemblies such as the body and chassis, beam structures like the front and rear bumper beams, A-pillar reinforcement beams, B-pillar reinforcement beams, door bumper beams, sill beams, roof crossbeams, dashboard crossbeams, and chassis beams typically utilize tubular components such as hot-expansion tubes to achieve high strength and lightweighting. Body tubular beam structures are usually designed with uniform wall thickness, and the thickness depends on the point of maximum collision stress required for that beam. This results in stiffness redundancy in areas of lower stress or less stringent stiffness requirements, leading to material and weight waste and failing to meet the demands for cost reduction and lightweighting. While some body tubular beam structures are designed with unequal wall thickness, these suffer from lower strength and higher manufacturing costs. Utility Model Content

[0003] This disclosure aims to at least partially address one of the technical problems in the related art.

[0004] Therefore, embodiments of this disclosure provide an automotive tubular component that has the advantages of high strength, light weight, and low cost.

[0005] Embodiments of this disclosure also propose a vehicle body and a vehicle.

[0006] The vehicle tubular component of this disclosure includes a transition section and at least two equal-thickness sections, wherein the transition section and the equal-thickness sections are arranged alternately and integrally formed, and any two adjacent equal-thickness sections have different thicknesses.

[0007] According to the embodiments of the present disclosure, the vehicle tubular component is integrally formed by setting a transition section and a section of equal thickness, which effectively reduces its manufacturing cost and makes it lighter and stronger.

[0008] In some embodiments, the thickness of the transition pipe section gradually increases along its extension direction, the thickness at the first end of the transition pipe section is equal to the thickness of the connected equal-thickness pipe section, and the thickness at the second end of the transition pipe section is equal to the thickness of the connected equal-thickness pipe section.

[0009] In some embodiments, the yield strength of the equal-thickness pipe section and the transition pipe section is greater than 300 MPa and the tensile strength is greater than 500 MPa.

[0010] In some embodiments, the yield strength of the equal-thickness pipe section and the transition pipe section is greater than 1400 MPa and the tensile strength is greater than 2200 MPa.

[0011] In some embodiments, the wall thickness of the equal-thickness pipe section is d, wherein 1mm≤d≤3.5mm.

[0012] In some embodiments, among at least two equal-thickness pipe sections, the ratio of the wall thickness of the equal-thickness pipe section with the largest wall thickness to the wall thickness of the equal-thickness pipe section with the smallest wall thickness is L, where L≤2.

[0013] In some embodiments, the ratio of the length of the transition section to the difference in wall thickness between two adjacent equal-thickness sections is M, where M ≥ 100.

[0014] In some embodiments, the automotive tubular component is a hot-expansion tube.

[0015] The vehicle body according to embodiments of this disclosure includes a vehicle tubular component as described in any of the above embodiments.

[0016] The technical advantages of the vehicle body according to the embodiments of this disclosure and the technical advantages of the vehicle tubular component in the above embodiments will not be repeated here.

[0017] The vehicle according to embodiments of this disclosure includes the body as described in the embodiments above.

[0018] The technical advantages of the vehicle according to the embodiments of this disclosure and the technical advantages of the body of the above embodiments will not be repeated here. Attached Figure Description

[0019] Figure 1 This is a cross-sectional view of a vehicle tubular component according to an embodiment of the present disclosure.

[0020] Figure 2 This is a partial cross-sectional view of a vehicle tubular component according to an embodiment of the present disclosure.

[0021] Figure 3 This is a schematic diagram of the joint welding of the rolled tube in the manufacturing method of the automotive tubular component according to an embodiment of the present disclosure.

[0022] Figure label:

[0023] 1. Equal thickness pipe section; 2. Transition pipe section; 3. Rolled pipe; 4. Heating coil. Detailed Implementation

[0024] Embodiments of this disclosure are described in detail below, with examples of these embodiments illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this disclosure, and should not be construed as limiting it.

[0025] The following describes a vehicle tubular component according to an embodiment of the present disclosure with reference to the accompanying drawings.

[0026] like Figure 1 and Figure 2As shown, the vehicle tubular component according to an embodiment of the present disclosure includes a transition section 2 and at least two equal-thickness sections 1, the transition section 2 and the equal-thickness sections 1 are arranged alternately and integrally formed, and any two adjacent equal-thickness sections 1 have different thicknesses.

[0027] According to the embodiments of the present disclosure, the vehicle tubular component is integrally formed by setting a transition section 2 and a section 1 of equal thickness, which effectively reduces its manufacturing cost and makes it lighter and stronger.

[0028] It should be noted that "equal thickness" in equal thickness pipe section 1 means that the wall thickness is equal at any location. The number of equal thickness pipe sections 1 is greater than the number of transition pipe sections 2, and the difference between the two is one. For example, as Figure 1 As shown, there are three equal-thickness pipe sections 1 and two transition pipe sections 2, both of which are straight pipe sections. The equal-thickness pipe section 1 located in the middle is bent.

[0029] In some embodiments, such as Figure 2 As shown, the thickness of the transition pipe section 2 gradually increases along its extension direction. The thickness at the first end of the transition pipe section 2 is equal to the thickness of the connected equal-thickness pipe section 1, and the thickness at the second end of the transition pipe section 2 is equal to the thickness of the connected equal-thickness pipe section 1.

[0030] That is, the inner circumferential surface of the transition pipe section 2 is directly connected to the inner circumferential surface of any pipe section 1 of equal thickness connected thereto, and the outer circumferential surface of the transition pipe section 2 is directly connected to the outer circumferential surface of any pipe section 1 of equal thickness connected thereto. This effectively avoids step changes in the wall thickness of the automotive tubular component, thereby effectively avoiding stress concentration at the connection between two adjacent pipe sections 1 of equal thickness, and further improving the strength of the automotive tubular component.

[0031] It is understandable that, before the automotive tubular component undergoes thermal expansion, the outer contour of the cross-section of any equal-thickness tube segment 1 is the same in size and shape as the outer contour of the cross-section of the transition tube segment 2. Optionally, before the automotive tubular component undergoes thermal expansion, both the outer contour of the cross-section of the equal-thickness tube segment 1 and the outer contour of the cross-section of the transition tube segment 2 are circular.

[0032] It should be noted that the cross-sectional outer contour of a vehicle tubular component may vary at any position along its length, and the specific shape depends on the actual use location and function of the vehicle tubular component.

[0033] In some embodiments, the yield strength of the equal-thickness tube section 1 and the transition tube section 2 is greater than 300 MPa and the tensile strength is greater than 500 MPa. This ensures that the automotive tubular components have sufficiently high strength and toughness, better meeting the usage requirements of various components in the vehicle body.

[0034] For example, the yield strength of the equal-thickness pipe section 1 and the transition pipe section 2 is 1400 MPa or above, and the tensile strength is 2200 MPa, 2400 MPa or above, respectively.

[0035] In some embodiments, the wall thickness of the equal-thickness pipe section 1 is d, where 1 mm ≤ d ≤ 3.5 mm. This ensures that it meets the strength requirements while reducing its weight, thus meeting the vehicle's lightweight requirements.

[0036] For example, the wall thickness d of the equal-thickness pipe section 1 is 1 mm, 2 mm and 3.5 mm.

[0037] In some embodiments, among at least two equal-thickness pipe sections 1, the ratio of the wall thickness of the equal-thickness pipe section 1 with the wall thickness of the one with the largest wall thickness to the wall thickness of the equal-thickness pipe section 1 with the smallest wall thickness is L, where L≤2. This avoids an excessive difference in wall thickness between the two equal-thickness pipe sections 1, which would lead to an excessive strength difference and prevent the overall load-bearing requirements of the automotive tubular component from being met.

[0038] For example, the ratio L of the wall thickness of the thickest equal-thickness pipe segment 1 to the wall thickness of the thinnest equal-thickness pipe segment 1 can be 1, 1.5, and 2.

[0039] Optionally, the ratio of the length of the transition section 2 to the difference in wall thickness between two adjacent equal-thickness sections 1 is M, where M ≥ 100. This effectively avoids stress concentration caused by an excessively short length of the transition section 2, further ensuring the strength and overall load-bearing requirements of the automotive tubular component.

[0040] In some embodiments, the automotive tubular component is a hot-air expansion tube. The integrally formed hot-air expansion tube with unequal thickness has higher strength and lower weight, further meeting the vehicle's lightweight requirements.

[0041] For example, the method for manufacturing a vehicle tubular component according to an embodiment of this disclosure includes the following steps:

[0042] Steel coils are rolled into steel coils of unequal thickness;

[0043] Divide steel coils of unequal thickness into steel strips of unequal thickness;

[0044] Unequal thickness steel strips are made into unequal thickness tube blanks;

[0045] The hot gas expansion process is used to form tube blanks of unequal thickness into hot gas expansion tubes.

[0046] According to the manufacturing method of the automotive tubular component according to the embodiments of this disclosure, after processing steel coils into steel coils of unequal thickness, the unequal thickness steel coils are cut into steel strips of unequal thickness with a set size. Then, the unequal thickness steel strips are made into tube blanks of unequal thickness. Finally, a hot air expansion process is used to form a hot air expansion tube of unequal thickness. Compared with the related art method of welding tube segments of different wall thicknesses together using a tenon and mortise structure to form hot air expansion tubes of unequal thickness, the manufacturing method of this embodiment has high production efficiency, low production cost, and produces automotive unequal thickness hot air expansion tubes with tube segments of different wall thicknesses integrally formed, resulting in higher strength.

[0047] It should be noted that "unequal thickness" in the above-mentioned unequal thickness steel coils, strips, and tube blanks refers to at least two regions having different wall thicknesses. Taking the unequal thickness tube blank as an example, the tube blank includes at least two sections with different wall thicknesses along its length. In the process of dividing the unequal thickness steel coil into unequal thickness steel strips, the unequal thickness steel coil is cut into unequal thickness steel strips of a set size along its length. The length direction of the unequal thickness steel strip, the axial direction of the hot gas expansion tube, and the axial direction of the unequal thickness steel coil are consistent. Furthermore, by cold rolling the steel coil into unequal thickness steel coils, the connection accuracy of the pipes of different thicknesses in the final formed hot gas expansion tube can be high, and multiple hot gas expansion tubes can be formed from only one steel coil, reducing the types of initial raw materials and further improving the manufacturing efficiency of the method for preparing automotive tubular parts.

[0048] In some embodiments, rolling a steel coil into a coil of unequal thickness includes:

[0049] The steel coils are flexibly rolled with unequal thickness using a cold rolling mill.

[0050] By performing unequal thickness flexible rolling, a continuous transition between different thickness sections of the unequal thickness steel coil can be achieved, that is, the thickness gradually changes at the transition point. This effectively avoids stress concentration at the connection between different thickness areas and further improves the strength of the final formed hot gas expansion tube.

[0051] For example, an unequal-thickness steel coil produced by unequal-thickness rolling includes at least two equal-thickness portions opposite each other along its axial direction and a transition portion with a gradually changing thickness, the transition portion connecting the two adjacent equal-thickness portions so that the thickness of the unequal-thickness steel coil changes gradually rather than abruptly changing in a step-like manner.

[0052] It should be noted that the equal-thickness steel coils were not quenched before rolling. The equal-thickness steel coils can be made from uncoated bare plates, or coated plates with aluminum-silicon coating or zinc coating, with aluminum-silicon coated cold-rolled plates being preferred.

[0053] In some embodiments, the method for manufacturing automotive tubular components further includes:

[0054] Unequal thickness steel coils are annealed at a temperature of 300℃-800℃ for a holding time of 3 minutes or more.

[0055] By performing the above annealing operation, the risk of cracking in unequal thickness steel coils is lower during subsequent welding and other processing steps, resulting in a higher yield and lower production cost of the final hot gas expansion tube.

[0056] For example, the above annealing process can be a continuous annealing process or a bell-type annealing process for the entire steel coil.

[0057] In some embodiments, forming unequal-thickness steel strips into unequal-thickness tube blanks includes:

[0058] The steel strips of varying thicknesses with a preset size are rolled into tubes 3 by roll forming, and the joints of the tubes 3 are welded to form tube blanks of varying thicknesses.

[0059] By using high-frequency resistance welding or laser welding to weld the joints of the rolled tube 3, the joints are sealed, which facilitates the formation of hollow tube blanks with openings at both ends that are only opposite to each other along their axial direction. At the same time, the tube blanks with unequal thickness are less likely to crack at the weld when subjected to radial impact. The resulting unequal thickness hot gas expansion tube has higher overall strength and a longer service life.

[0060] For example, due to the unequal thickness of the steel strip, during the roll forming process, the gap between one side of the rollers in the roller group is dynamically adjusted by a servo motor or hydraulic device. Because of the unequal thickness of the steel strip, the selection of high-frequency resistance welding and laser welding machines differs: when the thickness difference between the maximum and minimum thicknesses of the unequal-thickness strip is ≤0.8mm, a constant power high-frequency resistance welding or laser welding machine can be used; if the thickness difference is >0.8mm, the welding parameters of the high-frequency resistance welding or laser welding machine need to be dynamically adjusted to meet the welding process requirements for different thicknesses. After the steel strip is rolled, its two opposite edges are positioned opposite each other along its width direction, forming a seam for the rolled tube 3 between them.

[0061] The specific manufacturing process from unequal thickness steel coils to unequal thickness tube blanks is as follows: 1. Servo dynamic adjustment of roller gap to pre-form unequal thickness steel strips; 2. Dynamic adjustment of power for joint welding, such as high frequency welding or laser welding; 3. Online annealing of the weld area: induction heating and heat preservation of the weld; 4. Shaping and sizing; 5. Online flaw detection; 6. Sawing to form unequal thickness tube blanks of set dimensions.

[0062] In some embodiments, forming unequal-thickness steel strips into unequal-thickness tube blanks further includes:

[0063] After the joint welding of the rolled pipe 3 is completed, the weld area formed at the joint is annealed online; or, after forming the unequal thickness pipe blank, the unequal thickness pipe blank is annealed.

[0064] The above annealing process effectively reduces the hardness of the weld area of ​​the tube blank with unequal thickness, thereby effectively reducing the efficiency of subsequent cutting or bending, and also effectively reducing the risk of cracking in the weld area, further improving the yield of hot gas expansion tubes.

[0065] For example, such as Figure 3 As shown, during online annealing in the weld area, the heating coil 4 is located near the joint of the coiled tube 3.

[0066] It should be noted that weld annealing or whole-pipe annealing should be cancelled as much as possible without affecting subsequent processing, and the inner protrusion of the weld should be removed by a follow-up scraper.

[0067] In some embodiments, forming a tube blank of unequal thickness into a hot-expanded tube using a hot-expanding process includes:

[0068] A straight tube blank of unequal thickness is formed into a preformed tube blank through a tube bending process and / or a stamping process. The preformed tube blank is then heated to 900℃-980℃ and held for 2min-10min. It is then transferred to an air expansion mold and closed. High pressure gas is applied to achieve the molding and cooling of the preformed tube blank with the mold, so as to form a hot air expansion tube blank.

[0069] By using tube bending and / or stamping processes, straight tube blanks of varying thicknesses can be formed into pre-formed tube blanks of a set shape. This facilitates the matching of the outer contour of the hot-expansion tube blank with the outer contour of the required automotive tubular part after forming. As a result, after the final hot-expansion tube is formed, no further processing is required, thereby further improving the manufacturing efficiency and cost of automotive tubular parts.

[0070] For example, the preformed tube blank is heated by a multi-layer box furnace or a roller hearth furnace.

[0071] In some embodiments, the method for manufacturing automotive tubular components further includes:

[0072] The hot gas expansion tube blank is laser-cut to remove process-added parts and cut holes, thereby forming the final hot gas expansion tube with uneven thickness.

[0073] And / or, when the surface of the hot gas expansion tube blank is not coated, shot peening or sandblasting is used to remove the oxide scale on the surface and inner wall, thereby ensuring the stability and quality of subsequent processing, improving the corrosion resistance of the formed hot gas expansion tube, and extending its service life.

[0074] And / or, a hydrogen removal process is performed on the hot gas expansion tube blank by baking, with a baking temperature of 100℃-200℃ and a baking time of 10min-180min. This process is mainly for hot gas expansion tubes made of materials with a serious risk of delayed hydrogen embrittlement cracking. This setting effectively reduces the risk of cracking of hot gas expansion tubes and effectively extends their service life by removing hydrogen through baking.

[0075] The vehicle body according to embodiments of this disclosure includes a vehicle tubular component as described in any of the above embodiments.

[0076] The technical advantages of the vehicle body according to the embodiments of this disclosure and the technical advantages of the vehicle tubular component in the above embodiments will not be repeated here.

[0077] The vehicle according to embodiments of this disclosure includes the body as described in the above embodiments.

[0078] The technical advantages of the vehicle according to the embodiments of this disclosure and the technical advantages of the body of the above embodiments will not be repeated here.

[0079] In the description of this disclosure, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this disclosure and simplifying the description, and are not intended to 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 this disclosure.

[0080] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this disclosure, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0081] In this disclosure, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between components; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this disclosure according to the specific circumstances.

[0082] In this disclosure, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first and second features are in direct contact, or that the first and second features are in indirect contact 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.

[0083] In this disclosure, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this disclosure. 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.

[0084] Although the above embodiments have been shown and described, it is understood that the above embodiments are exemplary and should not be construed as limiting the present disclosure. Any changes, modifications, substitutions and variations made to the above embodiments by those skilled in the art are within the protection scope of this disclosure.

Claims

1. A tubular article for automotive use, characterized by, It includes a transition pipe section (2) and at least two equal-thickness pipe sections (1), the transition pipe section (2) and the equal-thickness pipe sections (1) are arranged alternately and integrally formed, and the thickness of any two adjacent equal-thickness pipe sections (1) is different.

2. The tubular for automotive use according to claim 1, characterized by The thickness of the transition pipe section (2) gradually increases along its extension direction. The thickness at the first end of the transition pipe section (2) is equal to the thickness of the equal-thickness pipe section (1) connected thereto. The thickness at the second end of the transition pipe section (2) is equal to the thickness of the equal-thickness pipe section (1) connected thereto.

3. The automotive tubular component according to claim 1, characterized in that, The yield strength of the equal-thickness pipe section (1) and the transition pipe section (2) is greater than 300 MPa and the tensile strength is greater than 500 MPa.

4. The tubular for automotive use according to claim 3, characterized by The yield strength of the equal-thickness pipe section (1) and the transition pipe section (2) is greater than 1400 MPa and the tensile strength is greater than 2200 MPa.

5. The tubular for automotive use according to claim 1, characterized by The wall thickness of the equal-thickness pipe section (1) is d, where 1mm≤d≤3.5mm.

6. The tubular for automotive use according to claim 1, characterized by Among at least two equal-thickness pipe sections (1), the ratio of the wall thickness of the equal-thickness pipe section (1) with the largest wall thickness to the wall thickness of the equal-thickness pipe section (1) with the smallest wall thickness is L, where L≤2.

7. The tubular for automotive use according to claim 1, characterized by The ratio of the length of the transition pipe section (2) to the difference in wall thickness between the two adjacent equal-thickness pipe sections (1) is M, where M≥100.

8. A tubular article for automotive use according to any one of claims 1 to 7, characterised in that The tubular component used in the vehicle is a hot-expansion tube.

9. A vehicle body, characterized by Including the automotive tubular component according to any one of claims 1-8.

10. A vehicle characterized by comprising: Includes the vehicle body as described in claim 9.

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