Aluminum alloy frame combined longitudinal beam

Abstract

The aluminum alloy frame combined longitudinal beam is composed of a front longitudinal beam, a rear longitudinal beam and a connecting plug plate. The front longitudinal beam and the rear longitudinal beam are offset in the transverse direction and form an overlapping combination area in the longitudinal direction. In the overlapping area, the two sides of the upper and lower connecting plug plates are respectively inserted into the connecting grooves on the sides of the front longitudinal beam and the rear longitudinal beam and welded to form a combined longitudinal beam. The present invention adopts a two-section longitudinal beam combined structure for connection. After further combining with the battery compartment on the frame, the overall structure has high rigidity and simple manufacturing. The offset between the front and rear longitudinal beams can be flexibly adjusted to adapt to different chassis leaf spring positions.

Description

Technical Field

[0001] The invention relates to the technical field of new energy vehicle manufacturing, in particular to an aluminum alloy frame combined longitudinal beam. Background Art

[0002] The frame is generally composed of longitudinal beams and cross beams, which are then connected by riveting or welding to form a solid rigid frame. In traditional steel structure frames, longitudinal beams are mainly channel-shaped or box-shaped sections, running through the entire body in the length direction, and can be curved in the horizontal or longitudinal plane according to the needs of other assembly parts.

[0003] In the field of new energy vehicles, aluminum alloy frames can be designed to reduce the weight of the frame, including aluminum alloy longitudinal beams. Although the elastic modulus of aluminum alloy is only one-third of that of steel, it has obvious advantages in light weight, but it also has the following disadvantages: 1) Aluminum alloy has high specific strength but low specific stiffness. In order to obtain good stiffness, the profile section must be reasonably designed and the profile height must be increased; 2) Aluminum alloy profiles are difficult to bend, especially large-section aluminum alloy profiles; 3) Aluminum alloy is not easy to weld. Welding should be minimized to reduce the damage to material properties caused by welding.

[0004] The following public documents on aluminum alloy longitudinal beams for vehicles were found: Keywords: longitudinal beam, aluminum alloy, combination

[0005] 1. A "two longitudinal and four transverse" aluminum alloy frame structure and automobile; Application number: CN201821389751.7; Applicant: Wuhan Intelligent Control Industrial Technology Research Institute Co., Ltd.; Huazhong University of Science and Technology; Abstract: A "two longitudinal and four transverse" aluminum alloy frame structure and automobile, belonging to the field of automobile technology. The "two longitudinal and four transverse" aluminum alloy frame structure includes two longitudinal beams and four combined cross arms. The two longitudinal beams are arranged symmetrically. The four combined cross arms are connected to the longitudinal beams in sequence from front to back. The automobile includes the above-mentioned "two longitudinal and four transverse" aluminum alloy frame structure. This "two longitudinal and four transverse" aluminum alloy frame structure ensures that it has good overall stiffness and strength while achieving lightweight, is easy to manufacture, and is also easy to install the aluminum alloy chassis hard point system. The automobile has a high degree of lightweight.

[0006] 2. An aluminum alloy automobile chassis hard point system and automobile; Application number: CN201810985616.7; Applicant: Wuhan Intelligent Control Industrial Technology Research Institute Co., Ltd.; Abstract: An aluminum alloy automobile chassis hard point system and automobile, belonging to the field of automobile technology. It includes a frame, a front leaf spring front support, a front leaf spring rear support, a rear leaf spring front support, a rear leaf spring rear support, a motor hard point support, and a steering hard point support. The frame includes a left longitudinal beam, a right longitudinal beam, a first combined cross arm, a second combined cross arm, a third combined cross arm, and a fourth combined cross arm, which are connected and fixed to the left longitudinal beam and the right longitudinal beam in sequence from front to back by mortise and tenon joints. The front leaf spring front support is connected to the first combined cross arm. The front leaf spring rear support is connected to the second combined cross arm. The rear leaf spring front support is connected to the third combined cross arm. The rear leaf spring rear support is connected to the fourth combined cross arm. The motor hard point support is fixed between the left longitudinal beam and the right longitudinal beam. The motor hard point support is fixed to the left longitudinal beam or the right longitudinal beam. This aluminum alloy automobile chassis hard point system has good hard point rigidity and strength while achieving lightweight.

[0007] 3. A pure electric vehicle chassis system using a lightweight bus chassis structure; Application number: CN201410847147.4; Applicant: Dongguan Sun Yat-sen University Research Institute; Dongguan Sanxin Electric Vehicle Technology Co., Ltd.; Abstract: A pure electric vehicle chassis system adopting a lightweight bus chassis structure includes two longitudinal beams and a plurality of cross beams, the plurality of cross beams are distributed at different height levels and different longitudinal positions of the two longitudinal beams, and the plurality of cross beams are mortised to the two longitudinal beams to form a double longitudinal beam multi-layer chassis frame that is subjected to overall force; the front part of the double longitudinal beam multi-layer chassis frame is connected to a front axle frame, which is fixed by two longitudinal beams; the rear part of the double longitudinal beam multi-layer chassis frame is connected to a rear axle frame; the rear axle frame is fixed by two longitudinal beams; the front axle frame is connected to a front axle assembly, and the rear axle frame is connected to a rear axle assembly, the double longitudinal beam multi-layer chassis frame is provided with a drive assembly and an energy assembly, the overall structural rigidity of the longitudinal beams is good, the assembly process of the front and rear axle frames and the chassis frame is simplified, the connection is firm and the overall force is achieved, and the multi-layer floor structure design facilitates the installation of batteries and motors and saves chassis space.

[0008] 4. A lightweight frame imitating the topology of a honeycomb structure; Application number: CN202010828647.9; Applicant: Huazhong University of Science and Technology; Nanning Huashu Lightweight Electric Vehicle Design Institute Co., Ltd.; Abstract: A lightweight frame imitating the topology of a honeycomb structure, characterized in that: it includes two side beams, at least one longitudinal beam, and at least two middle cross beams; the longitudinal beam is located between the two side beams, and the two ends of the middle cross beam are mortise-jointed with the side beams, and the middle part is mortise-jointed with the longitudinal beams; the side beams, longitudinal beams and middle cross beams all include a web with an "I"-shaped cross section in the middle, and an upper tube and a lower tube with rectangular cross sections at the upper and lower ends; a battery compartment that can be used to accommodate batteries is formed between the side beams, the longitudinal beams and the middle cross beams. The present invention adopts a frame with a multi-compartment honeycomb structure, which is light in weight and has a relatively high strength and rigidity, and can form a dual function of both load-bearing and weight reduction.

[0009] The above are the previous designs made by the applicant and the relevant development and design units, in which the longitudinal beams are all integrally designed, and the two integral longitudinal beams are arranged in parallel. Due to the different distances between the leaf springs of the front and rear axles of the chassis, the leaf spring hard points cannot be installed on the longitudinal beams at the same time. In order to adapt to different leaf spring moments, the above patents all take measures to separate the hard points from the longitudinal beams. Patents 1 and 2 design a combined crossbeam, and Patent 4 designs an integral crossbeam, providing leaf spring hard points on the outer side of the longitudinal beam, the combined crossbeam or the integral crossbeam according to the position requirements of the leaf spring. This scheme has two major shortcomings: 1) The combined crossbeam and the hard point structure are relatively complex, which increases the complexity of frame manufacturing; 2) There are many structures around the hard points, resulting in the assembly space of the hard point structure itself and the assembly space of the chassis leaf spring system being narrow, making the assembly operation difficult. Patent 3 provides leaf spring hard points through the front and rear axle frames made of steel, and the front and rear axle frames are first assembled on the beam. Although the hard point structure is relatively simple, the full aluminum alloy of the frame is not achieved, and the front and rear axle frames and hard points made of steel are prone to corrosion and are also heavy. In addition, in order to provide a good structural foundation for the combined crossbeam and the front and rear bridge frames, the cross-section of the beam is designed to be L-shaped or C-shaped, and the cavities on the profile cross-section are numerous and the shape is complex, which increases the difficulty of profile manufacturing.

[0010] In addition, there are relevant public documents as follows:

[0011] 5. Small gooseneck combined welded aluminum alloy longitudinal beam for semi-trailer; Application number: CN201410834985.8; Applicant: Liaoning Zhongwang Special Vehicle Manufacturing Co., Ltd.; Abstract: A small gooseneck combined welded aluminum alloy longitudinal beam for semi-trailer is disclosed, including a front upper beam, a middle neck beam and a rear lower beam, the front upper beam is a double-web I-beam, including a front upper wing plate, a front double web plate and a front lower wing plate, the middle neck beam includes at least two parallel right-angled triangle web plates, the rear lower beam is an I-beam, including a rear upper wing plate, a rear web plate and a rear lower wing plate, the right-angle sides I and II of the middle neck beam are respectively welded and fixed to the front end faces of the front lower wing plate and the rear lower beam, the end of the front upper beam is provided with a notch matched with the front end of the rear lower beam, and the front upper beam and the rear lower beam are welded and fixed by matching the notch. The aluminum alloy longitudinal beam for semi-trailer of the present invention adopts a three-section structure, which can enhance the structural strength, reduce the product manufacturing cost and improve the driving safety.

[0012] In the above documents, aluminum profiles with various cross sections are welded end to end to form a combined longitudinal beam structure of upper beams, middle neck beams and rear lower beams with multiple cross sections, which can reduce the extruded cross-sectional area of ​​the aluminum profiles, reduce the total weight, and reduce the tonnage of the extruder, thereby achieving the effect of reducing production costs.

[0013] However, the above technical scheme has the following disadvantages: large-area hot welding is performed on the joints of the aluminum alloy profiles, which will inevitably cause changes in the metal structure of the aluminum alloy, coarse grains, and a loss of at least 40% in the mechanical properties of the welding parts, which is not conducive to the stress of the overall structure of the longitudinal beam and is prone to stress concentration, weld cracking, etc.; in addition, the above scheme also requires the manufacture of multiple sets of extrusion dies for production and use, which is undoubtedly not conducive to cost reduction to a certain extent. Summary of the invention

[0014] The aluminum alloy frame combined longitudinal beam of the present invention is composed of two sections of longitudinal beams that are laterally offset and have a certain longitudinal overlap area. The lateral offset distance of the front and rear longitudinal beams is adjusted to adapt to the different widths of the front and rear leaf springs, thereby avoiding the difficulty of bending and forming the integral aluminum alloy beam, improving production efficiency, reducing production costs, and ensuring the mechanical properties of the combined longitudinal beam.

[0015] To achieve the above object, the technical solution of the present invention is as follows:

[0016] The aluminum alloy frame combined longitudinal beam is composed of a front longitudinal beam, a rear longitudinal beam and a connecting plug plate. The front longitudinal beam and the rear longitudinal beam are offset in the transverse direction and form an overlapping combination area in the longitudinal direction. In the overlapping area, the two side edges of the upper and lower connecting plug plates are respectively inserted into the connecting plug plate grooves on the sides of the front longitudinal beam and the rear longitudinal beam and welded to form a combined longitudinal beam.

[0017] A connecting plug is provided at the overlapping connection part of the front longitudinal beam and the rear longitudinal beam, and the two side ends of the connecting plug are fixedly connected to the side of the front longitudinal beam and the rear longitudinal beam respectively. On this basis, a connecting plug is added between the front longitudinal beam and the rear longitudinal beam to further increase the connection nodes between the two. In actual production, after the front longitudinal beam and the rear longitudinal beam are produced to a fixed length, the connecting plug is first used to fix the two to form a combined longitudinal beam, and then the combined longitudinal beam is connected to the cross beam, the battery tunnel cavity, etc.

[0018] At least one group of battery compartment reserved holes is arranged in the overlapping combination area of ​​the front longitudinal beam and the rear longitudinal beam, and the battery compartment is respectively connected with the front longitudinal beam and the rear longitudinal beam through the reserved holes in cooperation with mortise and tenon joints.

[0019] The front longitudinal beam and the rear longitudinal beam mainly form the main structural topology through the connection of the battery compartment. They have strong rigidity and torsion resistance, and the profile cross-section structure is reasonable and easy to produce. Secondly, the distance between the two rear longitudinal beams after the combination can be adjusted within a certain range, which greatly facilitates the adaptive adjustment of the installation position of hard point supports such as leaf spring supports on the longitudinal beams. There is no need to bend the longitudinal beams, which greatly reduces the manufacturing cost of the frame.

[0020] The front longitudinal beam and the rear longitudinal beam are multi-cavity aluminum profiles with the same cross-section. The uppermost and lowermost cavity sides are provided with connecting plate slots, and the connecting plates and the slots are fixed at the edges by welding. The multi-cavity aluminum profile is similar to a double-web structure, and the partitions between the cavities strengthen the web connection, so that the longitudinal beam profile has strong compression and torsion resistance, ensuring the overall rigidity of the longitudinal beam.

[0021] In the cavities of the front longitudinal beam and the rear longitudinal beam, a plurality of reinforcing ribs are arranged on both sides of the long cavity. The reinforcing ribs can further improve the stress condition of the side walls of the long cavity and enhance the bending resistance of the longitudinal beam.

[0022] The front longitudinal beam and the rear longitudinal beam are provided with holes for the cross beam, and the longitudinal beams and the cross beams are connected by a tenon-tenon structure. The cross beam profile section is provided with the same connecting plate groove, which is connected to the triangular plate and fixed at the edge by welding. The longitudinal beams and the cross beams are mutually supported and connected by the tenon-tenon structure, forming a longitudinal and transverse frame structure for supporting the floor of the vehicle.

[0023] Advantages of the present invention:

[0024] 1. The two-section combined structure of the longitudinal beam structure of the present invention directly adapts to the different widths of the front and rear leaf springs by decomposing the integral longitudinal beam into the front and rear end longitudinal beams with overlapping areas and connecting them, so as to directly arrange the leaf spring hard points on the longitudinal beams and improve the load-bearing capacity of the frame. Since the spacing between the front and rear longitudinal beams can be flexibly adjusted, the application range of the combined longitudinal beam is very flexible.

[0025] 2. The combined longitudinal beam of the present invention can avoid the use of a single longitudinal beam profile for bending and forming, thereby avoiding the disadvantages of high processing cost and low yield caused by the bending of the profile.

[0026] 3. The connecting sides of the longitudinal beam and the upper and lower ribs of the combined longitudinal beam structure of the present invention are longer, and are further combined with the battery compartment in the frame, so as to have higher bending and torsional resistance, which is beneficial to improving the overall structural rigidity of the frame.

[0027] 4. The combined longitudinal beam structure of the present invention has relatively simple production process in actual production, which improves the frame assembly efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is the appearance structure diagram of the present invention;

[0029] Figure 2 This is a structural elevation diagram of the present invention combined with a battery compartment (two combined longitudinal beams + two battery compartments);

[0030] Figure 3 This is a main structural diagram of the present invention;

[0031] Figure 4 for Figure 3 Middle AA section structure diagram;

[0032] Figure 5 for Figure 3 The enlarged structural diagram at middle Ⅱ;

[0033] Figure 6 The attached structural diagram of the present invention;

[0034] Figure 7 for Figure 6 The enlarged structure diagram at position Ⅰ in the middle;

[0035] The numbers in the figure are: 1. front longitudinal beam; 2. rear longitudinal beam; 3. connecting plug plate; 4. cross beam; 5. reserved hole for battery compartment; 6. battery compartment. DETAILED DESCRIPTION

[0036] Example 1

[0037] The aluminum alloy frame combined longitudinal beam is composed of a front longitudinal beam 1, a rear longitudinal beam 2 and a connecting plug 3. The front longitudinal beam 11 and the rear longitudinal beam 12 are offset in the transverse direction and form an overlapping combined area in the longitudinal direction. In the overlapping area, the two side edges of the upper and lower connecting plugs 3 are respectively inserted into the connecting plug grooves on the side surfaces of the front longitudinal beam 1 and the rear longitudinal beam 2 and are welded and fixed to form a combined longitudinal beam.

[0038] A group of battery compartment reserved holes 5 are arranged in the overlapping combination area of ​​the front longitudinal beam 1 and the rear longitudinal beam 2, and the battery compartment 6 is connected to the front longitudinal beam 1 and the rear longitudinal beam 2 through the reserved holes respectively;

[0039] The front longitudinal beam 1 and the rear longitudinal beam 2 are multi-cavity aluminum profiles with the same cross-section, and the uppermost and lowermost cavity sides thereof are provided with connecting plate grooves, and the connecting plate 3 is fixed to the groove by welding the edges;

[0040] In the cavities of the front longitudinal beam 1 and the rear longitudinal beam 2, a plurality of reinforcing ribs are arranged on both sides of the long cavities;

[0041] The front longitudinal beam 1 and the rear longitudinal beam 2 are provided with holes for the cross beam 4, and the longitudinal beam and the cross beam 4 are connected by a tenon-tenon structure. The cross beam 4 profile section is provided with the same connecting plate groove, which is connected to the end edge of the connecting plate 3 and fixed at the edge by welding.

[0042] Example 2

[0043] The difference from Example 1 is that two groups of battery compartment reserved holes 5 are arranged in the overlapping combination area of ​​the front longitudinal beam 1 and the rear longitudinal beam 2, and the two battery compartments 6 are respectively connected to the front longitudinal beam 11 and the rear longitudinal beam 12 through the reserved holes.

[0044] Application examples:

[0045] The aluminum profiles of the present invention are all processed and manufactured using 6005A-T6 materials. The total length of the combined longitudinal beam is 5800mm, the length of the front longitudinal beam is 3000mm, the length of the rear longitudinal beam is 4300mm, and the combined length of the two is 1300mm.

[0046] Comparative example: longitudinal beams with the same longitudinal beam cross-section and a total length of 6000 mm:

[0047]

[0048] Extrusion process yield: total weight of aluminum ingot input / final finished aluminum weight*100%.

[0049] The reason is that after the profile is shortened, the production calculation of the ingot length is more flexible, and the range of the ingot length can be adjusted to be wider, so that longer aluminum ingots can be used to enter the extruder for extrusion production, reducing the total excess weight of the extruded ingot; secondly, after the extruded profile is cut to length, if there is a defect (bump, etc.) in the production process, the original long 4300mm profile can be sawed into a short 3000mm profile, or the defect can be avoided and the remaining length can be flexibly sawed to a suitable length.

[0050] Application Example 2:

[0051] The aluminum profiles of Example 1 of the present invention are all processed and manufactured using 6005A-T6 material. The total length of the combined longitudinal beam is 5800mm, the length of the front longitudinal beam is 3000mm, the length of the rear longitudinal beam is 4300mm, and the combined length of the two is 1300mm; the distance between the two front longitudinal beams is 673mm, and the distance between the two rear longitudinal beams is 1138mm.

[0052] Comparative example: A single profile is used for roll bending, the distance between the two longitudinal beams is 673mm at the front, and 1138mm at the rear. The three-roller roll bending machine rolls the longitudinal beams, and the middle part of the longitudinal beam is rolled into an S shape. The profile length is 6000mm, and the roll bending mold cost is 300,000 yuan / set.

[0053] Comparing a single rolled frame longitudinal beam with the combined longitudinal beam of the present invention, the longitudinal beam profile weight per meter is 7.283 kg / m.

[0054]

[0055] Note: The cost includes material cost, extrusion production cost, machining cost and profile rolling cost, but does not include the amortized cost of the rolling mold.

[0056] It can be seen from this that after taking into account the rolling cost, the manufacturing cost of the rolled longitudinal beam is still slightly higher than the cost of the combined longitudinal beam, and the amortized cost of the rolling mold has not yet been calculated.

[0057] The comparative example rolling longitudinal beam and the combined longitudinal beam of Example 1 of the present invention are added with other rods to form a frame, and then subjected to a torsion resistance test:

[0058]

[0059] The above torsional stiffness test process follows the experimental method in the 2020 draft for comments on the "Test Method for Torsional Stiffness of Ordinary Passenger Vehicle Body-in-White":

[0060] The test device meets the requirements of JB / T 7974-1999. The body-in-white and the simulated suspension are connected by a ball joint. A total of 20 measuring points are set symmetrically on the bottom of the body. The maximum load is one-fourth of the maximum load of the whole vehicle.

[0061] Load clockwise to maximum load----unload----load counterclockwise to maximum load----unload----stand still to eliminate elastic deformation----load clockwise to 30% of maximum load----unload----load counterclockwise to 30% of maximum load----unload----stand still to eliminate elastic deformation----load in stages clockwise----unload to eliminate elastic deformation----load counterclockwise to 30% of maximum load----unload----load in stages counterclockwise----unload to eliminate elastic deformation----repeat steps 6-16 several times, at least 2 times.

[0062] Calculation formula: Torsional stiffness = load borne by the vehicle body / absolute value of the difference in torsion angle between the front and rear suspension cross sections

[0063] It can be seen that the frame using a combined longitudinal beam, although slightly heavier than the bent longitudinal beam frame, has greatly improved its anti-torsion capability.

Claims

1. Aluminum alloy frame combined longitudinal beam, characterized by: The invention comprises a front longitudinal beam (1), a rear longitudinal beam (2) and a connecting plug plate (3), wherein the front longitudinal beam (11) and the rear longitudinal beam (12) are offset in the transverse direction and form an overlapping combination area in the longitudinal direction, and in the overlapping area, the two side edges of the upper and lower connecting plug plates (3) are respectively inserted into the connecting plug plate grooves on the side surfaces of the front longitudinal beam (1) and the rear longitudinal beam (2) and are welded and fixed to form a combined longitudinal beam; At least one set of battery compartment reserved holes (5) is arranged in the overlapping combination area of ​​the front longitudinal beam (1) and the rear longitudinal beam (2), and the battery compartment (6) is respectively connected to the front longitudinal beam (1) and the rear longitudinal beam (2) by mortise and tenon joints through the reserved holes; The front longitudinal beam (1) and the rear longitudinal beam (2) are multi-cavity aluminum profiles with the same cross-section, and the uppermost and lowermost cavity sides thereof are provided with connecting plate grooves, and the connecting plates (3) are fixed to the grooves by welding the edges thereof; The front longitudinal beam (1) and the rear longitudinal beam (2) are provided with holes for the cross beam (4), the longitudinal beam and the cross beam (4) are connected by a tenon-tenon structure, the cross beam (4) is provided with a similar connecting plate groove in the cross section, connected to the end edge of the connecting plate (3), and fixed at the edge by welding.

2. The aluminum alloy frame combined longitudinal beam according to claim 1, characterized in that: In the cavities of the front longitudinal beam (1) and the rear longitudinal beam (2), a plurality of reinforcing ribs are arranged on both sides of the long cavities.

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