Power battery rolling steel lower box body integrated structure, forming method thereof and vehicle

Abstract

The invention relates to a power battery rolling steel lower box integrated structure, a forming method thereof and a vehicle, the integrated structure comprises a frame assembly, a mounting assembly, a heat management assembly and a bottom protection assembly; the mounting assembly is integrated with the frame assembly through spot welding; the heat management assembly is integrated with the frame assembly through self-plugging rivets. The bottom protection assembly is connected through bolts and is integrated with the mounting assembly, the heat management assembly and the frame assembly. The bottom protection assembly and the side mounting assembly are directly integrated. The battery pack lower box body side mounting and the frame are formed respectively, and eight sections of sectional materials of the whole frame can share the same mold; the integrated design of the side mounting and the bottom protection plate is adopted, so that the mechanical strength and the safety of the side edge of the power battery are effectively improved; a local reinforcing structure between the side hanging load and the bottom protection plate effectively improves the mechanical strength and safety of the side edge of the power battery, and the local reinforcing structure has flexibility and can be designed according to the safety position requirement of the whole vehicle; the local reinforcing structure can reduce the overall cost and the weight.

Description

Technical Field

[0001] The present invention belongs to the technical field of roll-formed steel lower boxes for power batteries, and in particular relates to an integrated structure of a roll-formed steel lower box for a power battery, a forming method thereof, and a vehicle. Background Art

[0002] In the existing technology, in order to reduce costs, steel battery packs have attracted the attention and favor of OEMs and battery manufacturers.

[0003] However, the current design and forming of the roll-formed steel lower box of power batteries still have the following problems:

[0004] 1. Welding corrosion: Since steel has a worse corrosion resistance than aluminum, especially arc welding welds, they are very susceptible to corrosion even after electrophoresis treatment.

[0005] 2. Sealing failure: As the wall thickness of the lower box of the power battery rolled steel is relatively thin, arc welding often easily penetrates, resulting in sealing failure.

[0006] 3. Poor mechanical strength: The wall thickness of the box body is relatively thin under roll forming, and local reinforcement cannot be achieved.

[0007] 4. High mold opening cost: There are many types of roll-formed profile cross-sections, and the mold opening cost is high.

[0008] 5. High manufacturing cost: The sealing surface requires laser welding, which has high welding cost.

[0009] At the same time, the traditional arc welding method is used during the molding process, which is prone to arc welding seal failure and arc welding penetration. Based on this, it is urgent to develop an integrated structure of the lower box of the power battery roll-pressed steel to effectively solve the above problems. Summary of the invention

[0010] The purpose of the present invention is to provide an integrated structure of a power battery rolled steel lower box, a forming method thereof and a vehicle, so as to solve the problems of welding corrosion, sealing failure, poor mechanical strength, high manufacturing cost, arc welding sealing failure and arc welding penetration existing in the power battery rolled steel lower box.

[0011] The objective of the present invention is achieved through the following technical solutions:

[0012] A method for forming a power battery roll-formed steel lower box integrated structure comprises the following steps:

[0013] A frame component molding:

[0014] A1. Frame roll profile forming: Through the roll-pressing process, it is rolled into a Japanese-shaped cross-section profile, and the splicing interface is welded by laser welding;

[0015] A2. Cutting of profile length: Cut the rolled profiles of corresponding lengths according to the frame component profiles 1, 2, 3, 4, 5, 6, 7 and 8;

[0016] A3. Cutting of profile installation holes: Pre-drill holes for rivets, blind rivets, and spot welding according to the corresponding positions of the main frame;

[0017] A4. Profile welding angle cutting: profile welding position, 45° angle cutting; frame assembly welding;

[0018] A5. Frame assembly welding: Profile 1, Profile 2, Profile 3, Profile 4, Profile 5, Profile 6, Profile 7 and Profile 8 are welded by laser welding;

[0019] A6, frame assembly molding is completed;

[0020] A7. Welding of internal reinforcement components and frame components;

[0021] A8. The mounting assembly is spot welded to the frame assembly;

[0022] A9, the thermal management component is connected to the frame component with blind rivets;

[0023] A10. Welding of side mount and reinforcement: The reinforcement is integrated with the side mount by welding;

[0024] A11, the bottom guard plate assembly is integrated with the thermal management assembly and the frame assembly through bolt connection;

[0025] A12, the bottom guard plate assembly and the mounting assembly are integrated by bolt connection;

[0026] A13. The integration of the power battery roll-formed steel lower box is completed.

[0027] Furthermore, it includes a frame assembly, a mounting assembly, a thermal management assembly and a bottom protection assembly; the mounting assembly is integrated with the frame assembly by spot welding; the thermal management assembly is integrated with the frame assembly by blind rivets; the bottom protection assembly is integrated with the mounting assembly, the thermal management assembly and the frame assembly by bolt connection, and the bottom protection assembly is directly integrated with the side mounting assembly;

[0028] Wherein, the frame assembly includes a frame assembly and an internal reinforcement assembly; the frame assembly and the internal reinforcement assembly are integrated by welding; each section of the profile has a cutting hole on the inner side of the frame assembly, and a blind rivet opening is reserved on the lower side of the frame assembly, and the blind rivet opening and the rivet nut opening are alternately distributed; the internal reinforcement assembly includes a longitudinal beam, a front cross beam 1, a middle cross beam, a front cross beam 2, a rear reinforcement plate, a front reinforcement plate 1, a front reinforcement plate 2, a front reinforcement plate 3 and a front reinforcement plate 4; the connections between the internal reinforcement assemblies are integrated by welding;

[0029] The mounting assembly includes a front mounting assembly, a rear mounting assembly, a side mounting assembly and a middle mounting assembly; the side mounting assembly includes a side mounting body, a welding nut, a sleeve and a reinforcement; the side mounting assembly and the lower box frame are formed separately so that the entire frame mold is shared; the side mounting assembly and the lower box frame are integrated by spot welding; the side mounting assembly and the lower box frame are connected by spot welding; the front mounting assembly includes a front mounting body and a sleeve, the front mounting assembly and the frame assembly are integrated by spot welding, and the front mounting assembly and the frame assembly are connected by spot welding; the rear mounting assembly includes a front mounting body and a sleeve, the rear mounting assembly and the frame assembly are integrated by spot welding, and the rear mounting assembly and the frame assembly are connected by spot welding;

[0030] The bottom guard plate assembly includes a bottom guard plate body, a bottom spray material and a bolt assembly. The bottom guard plate assembly is connected by bolts and integrated with the side mounting assembly. The bottom guard plate assembly is directly integrated with the side mounting assembly.

[0031] Furthermore, the opening spacing of the blind rivets is 80-90mm, and the opening diameter is 5-6mm; the lower side of the frame assembly reserves rivet nut openings, and the opening spacing of the rivet nuts is 80-90mm, and the opening diameter is 7-8mm.

[0032] Furthermore, the frame assembly includes profile 1, profile 2, profile 3, profile 4, profile 5, profile 6, profile 7, and profile 8; the frame assembly is welded and integrated by profile 1, profile 2, profile 3, profile 4, profile 5, profile 6, profile 7, and profile 8; the profile 1, profile 2, profile 3, profile 4, profile 5, profile 6, profile 7, and profile 8 have the same cross-section and are common mold parts; the material of the profiles 1 to 8 is steel, the cross-section is an I-shaped cross-section, the cross-section width is 25mm-35mm, the cross-section height is 95mm-115mm, and the wall thickness is 0.8-1.5mm; the profiles 1 to 8 are roller formed.

[0033] Furthermore, the longitudinal beam, front cross beam 1, middle cross beam, and front cross beam 2 adopt a U-shaped or S-shaped cross section and are formed by a rolling process; the material is steel, the cross-sectional width is 25mm-45mm, the cross-sectional height is 75mm-95mm, and the wall thickness is 0.8-1.5mm; the rear reinforcement plate, front reinforcement plate 1, front reinforcement plate 2, front reinforcement plate 3, and front reinforcement plate 4 adopt a U-shaped cross section and are formed by stamping; the material is steel, the cross-sectional width is 25mm-45mm, the cross-sectional height is 75mm-95mm, and the wall thickness is 0.8-1.5mm; the middle cross beam has a middle mounting component installation hole; and the rear reinforcement plate has a cutting hole.

[0034] Furthermore, the side mount body is made of high-strength steel with a wall thickness of 1.0mm-2.0mm; the side mount body is formed by stamping; the welding nut is M6 or M8, the distance between nuts is 100mm-200mm, and the nut is welded and integrated with the side mount body.

[0035] Furthermore, the reinforcement is made of high-strength steel, with a U-shaped cross-section profile, a wall thickness of 1.0mm-2.0mm, a width of 40mm-50mm, and a height of 15mm-20mm; the reinforcement is integrated under the side mounting body by welding; the lower surface of the reinforcement is coated with foamed structural adhesive, and is connected to the bottom guard plate through the foamed structural adhesive; the position and number of the reinforcement are determined by the side collision requirements of the entire vehicle; the number of reinforcements on a single side of the battery pack is 1-3.

[0036] Furthermore, the front mount body is made of high-strength steel with a wall thickness of 1.0mm-2.0mm; the front mount body is formed by stamping; the sleeve material and specifications are consistent with the side mount assembly sleeve; the rear mount body is made of high-strength steel with a wall thickness of 1.0mm-2.0mm; the rear mount body is formed by stamping; the sleeve material and specifications are consistent with the side mount assembly sleeve.

[0037] Furthermore, the bottom guard plate body has a sleeve installation structure. After the sleeve is installed, it is ensured that the bottom surface of the sleeve is in contact with the upper surface of the bottom guard plate body; the bottom guard plate body has a reinforcement installation structure. After the reinforcement is installed, it is ensured that the bottom surface of the reinforcement is in contact with the upper surface of the bottom guard plate body and they are bonded together by foam structural adhesive; the bottom guard plate assembly is connected by bolts and integrated with the water cooling plate and the lower box frame.

[0038] A vehicle comprises the above-mentioned power battery rolled steel lower box integrated structure.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] The integrated structure of the roll-pressed steel lower box of the power battery of the present invention, the side mounting and the frame of the lower box of the battery pack are formed separately, and the 8 sections of the entire frame profile can be molded together, reducing the mold opening cost;

[0041] 2. The mounting and frame are changed from traditional arc welding to spot welding by opening holes on the inside of the box, which effectively solves the problems of arc welding seal failure and arc welding penetration;

[0042] 3. The spot-welded avoidance holes on the inside of the lower box have a good weight-reducing effect;

[0043] 4. The integrated design of side mount and bottom guard plate effectively improves the mechanical strength and safety of the power battery side (Y direction);

[0044] 5. The local reinforcement structure between the side mount and the bottom guard plate effectively improves the mechanical strength and safety of the power battery side (Y direction), and the local reinforcement structure is flexible and can be designed according to the safety position requirements of the vehicle; the local reinforcement structure can reduce the overall cost and weight;

[0045] 6. The bottom guard plate is connected with the side mounting assembly and the frame assembly by bolts, which is removable and easy to maintain. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0047] Figure 1-Figure 2 Schematic diagram of the power battery roll-formed steel lower box-frame assembly, mounting assembly, thermal management assembly, and bottom protection assembly;

[0048] Figure 3 It is a schematic diagram of the frame assembly-frame assembly and internal reinforcement assembly;

[0049] Figure 4-Figure 5 It is a schematic diagram of the frame components - profile 1, profile 2, profile 3, profile 4, profile 5, profile 6, profile 7, and profile 8;

[0050] Figure 6 It is a schematic diagram of the internal reinforcement components - longitudinal beam, front cross beam 1, middle cross beam, front cross beam 2, rear reinforcement plate, front reinforcement plate 1, front reinforcement plate 2, front reinforcement plate 3, front reinforcement plate 4;

[0051] Figure 7 It is a schematic diagram of the mounting components - front mounting components, rear mounting components, side mounting components, and middle mounting components;

[0052] Figure 8 This is a schematic diagram of the side-mounted assembly;

[0053] Fig. 9 It is a schematic diagram of the front mount assembly - the front mount body and sleeve;

[0054] Fig.10 It is a schematic diagram of the rear mount assembly - the rear mount body and sleeve;

[0055] Fig.11 Schematic diagram of the bottom guard plate assembly. DETAILED DESCRIPTION

[0056] The present invention will be further described below in conjunction with embodiments:

[0057] The present invention provides a method for forming a body of a power battery roll-pressed steel lower box integrated structure, which changes from traditional arc welding to spot welding through mounting and frame and opening holes in the box body, effectively solving the arc welding seal failure problem and arc welding penetration problem. The forming method comprises the following steps:

[0058] A frame component molding:

[0059] A1. Frame roll profile forming: Through the roll-pressing process, it is rolled into a Japanese-shaped cross-section profile, and the splicing interface is welded by laser welding.

[0060] A2. Cutting of profile length: Cut the rolled profiles into corresponding lengths according to the frame component profiles 1, 2, 3, 4, 5, 6, 7 and 8.

[0061] A3. Cutting of profile installation holes: Pre-drill holes for pull rivets, blind rivets, and spot welding according to the corresponding positions of the main frame.

[0062] A4. Profile welding angle cutting: At the profile welding position, make a 45° angle cut; frame assembly welding.

[0063] A5. Frame assembly welding: Profile 1, Profile 2, Profile 3, Profile 4, Profile 5, Profile 6, Profile 7, and Profile 8 are welded by laser welding.

[0064] A6. The frame assembly is completed.

[0065] A7. Welding of internal reinforcement components and frame components.

[0066] A8. The mounting assembly and the frame assembly are connected by spot welding.

[0067] A9. The thermal management component is connected to the frame component by blind rivets.

[0068] A10. Welding of side mount and reinforcement: The reinforcement is integrated with the side mount by welding.

[0069] A11, the bottom guard plate assembly is integrated with the thermal management assembly and the frame assembly through bolt connection.

[0070] A12. The bottom guard plate assembly and the mounting assembly are integrated by bolt connection.

[0071] A13. The integration of the power battery roll-formed steel lower box is completed.

[0072] The present invention also provides an integrated structure of a power battery roll-formed steel lower box, in which the side mounts and the frame of the battery pack lower box are formed separately, and the 8 sections of the entire frame profile can be co-molded to reduce the mold opening cost. The integrated design of the side mount and the bottom guard plate effectively improves the mechanical strength and safety of the side (Y direction) of the power battery. The local reinforcement structure between the side mount and the bottom guard plate effectively improves the mechanical strength and safety of the side (Y direction) of the power battery, and the local reinforcement structure is flexible and can be designed according to the safety position requirements of the entire vehicle. The local reinforcement structure can reduce overall cost and weight.

[0073] The integrated structure of the lower box of the power battery rolled steel of the present invention includes a frame assembly, a mounting assembly, a thermal management assembly and a bottom protection assembly. The mounting assembly is integrated with the frame assembly by spot welding to avoid the risk of corrosion of arc welding seams of traditional rolled box bodies. The thermal management assembly is integrated with the frame assembly by blind rivets. The bottom protection assembly is integrated with the mounting assembly, the thermal management assembly and the frame assembly by bolt connection. The bottom protection assembly is directly integrated with the side mounting assembly, which effectively improves the strength of the side of the battery pack.

[0074] The frame assembly includes a frame assembly and an internal reinforcement assembly. The frame assembly and the internal reinforcement assembly are integrated by welding.

[0075] Each section of the profile has a cutting hole on the inner side of the frame assembly, which serves to reduce weight and avoid spot welding. The lower side of the frame assembly is reserved for openings for blind rivets, with a spacing of 80-90mm between the openings and an opening diameter of 5-6mm. The lower side of the frame assembly is reserved for openings for rivet nuts, with a spacing of 80-90mm between the openings and an opening diameter of 7-8mm. The openings for blind rivets and rivet nuts are distributed alternately.

[0076] The frame assembly includes profile 1, profile 2, profile 3, profile 4, profile 5, profile 6, profile 7, and profile 8. The frame assembly is welded and integrated by profile 1, profile 2, profile 3, profile 4, profile 5, profile 6, profile 7, and profile 8. The profiles 1, profile 2, profile 3, profile 4, profile 5, profile 6, profile 7, and profile 8 are of the same cross section and common mold parts. The maximum platformization reduces the mold opening cost. The material of the profiles 1 to 8 is steel, the cross section is a Japanese-shaped cross section, the cross section width is 25mm-35mm, the cross section height is 95mm-115mm, and the wall thickness is 0.8-1.5mm. The profiles 1 to 8 are formed by roller pressing.

[0077] The internal reinforcement components include longitudinal beams, front cross beams 1, middle cross beams, front cross beams 2, rear reinforcement plates, front reinforcement plates 1, front reinforcement plates 2, front reinforcement plates 3 and front reinforcement plates 4. The connections between the internal reinforcement components are integrated by welding. The longitudinal beams, front cross beams 1, middle cross beams and front cross beams 2 adopt a U-shaped or a Japanese-shaped cross section and are formed by a rolling process. The material selected is steel, with a cross-sectional width of 25mm-45mm, a cross-sectional height of 75mm-95mm, and a wall thickness of 0.8-1.5mm. The rear reinforcement plate, front reinforcement plate 1, front reinforcement plate 2, front reinforcement plate 3 and front reinforcement plate 4 adopt a U-shaped cross section and are stamped. The material selected is steel, with a cross-sectional width of 25mm-45mm, a cross-sectional height of 75mm-95mm, and a wall thickness of 0.8-1.5mm. The middle cross beam has a middle mounting assembly installation hole. The rear reinforcement plate has a cutting hole, which serves to reduce weight on the one hand and to avoid spot welding holes on the other hand.

[0078] The mounting assembly includes a front mounting assembly, a rear mounting assembly, a side mounting assembly and a middle mounting assembly.

[0079] The side mounting assembly includes a side mounting body, a welding nut, a sleeve and a reinforcement.

[0080] The side mount assembly is formed separately from the lower box frame, so that the entire frame mold is shared, the frame design is more platform-oriented, and the mold cost of the traditional design is reduced. The side mount assembly is integrated with the lower box frame by spot welding. The side mount assembly is connected to the lower box frame by spot welding, avoiding the risk of weld corrosion caused by arc welding. The side mount body is made of high-strength steel with a wall thickness of 1.0mm-2.0mm. The side mount body is formed by stamping.

[0081] The welding nut adopts M6 or M8, the distance between nuts is 100mm-200mm, and the nut is welded and integrated with the side mounting body.

[0082] The sleeve is made of steel, machined and formed, and the sleeve and the side mount body are integrated by welding, crimping or gluing. The sleeve can also be made of aluminum, machined or die-casted, and the sleeve and the side mount body are integrated by crimping or gluing.

[0083] The reinforcement is made of high-strength steel with a U-shaped cross-section profile and a wall thickness of 1.0mm-2.0mm. The width is 40mm-50mm and the height is 15mm-20mm. The reinforcement is integrated under the side mount body by welding. The lower surface of the reinforcement is coated with foam structural adhesive and connected to the bottom guard plate through the foam structural adhesive. The position and number of the reinforcements are determined by the side collision requirements of the entire vehicle. The number of reinforcements on a single side of the battery pack is 1-3.

[0084] The front mount assembly includes a front mount body and a sleeve. The front mount assembly and the frame assembly are integrated by spot welding. The front mount assembly and the frame assembly are connected by spot welding, which avoids the risk of weld corrosion caused by arc welding. The front mount body is made of high-strength steel with a wall thickness of 1.0mm-2.0mm. The front mount body is formed by stamping. The sleeve material and specifications are consistent with the side mount assembly sleeve.

[0085] The rear mount assembly includes a front mount body and a sleeve. The rear mount assembly and the frame assembly are integrated by spot welding. The rear mount assembly and the frame assembly are connected by spot welding, which avoids the risk of weld corrosion caused by arc welding. The rear mount body is made of high-strength steel with a wall thickness of 1.0mm-2.0mm. The rear mount body is formed by stamping. The sleeve material and specifications are consistent with the side mount assembly sleeve.

[0086] The bottom guard plate assembly includes a bottom guard plate body, a bottom spray material and a bolt assembly. The bottom guard plate body is made of ultra-high-strength steel with a wall thickness of 0.8-1.5mm, and is stamped, or ultra-high-strength steel is thermoformed. The bottom guard plate body has a sleeve installation structure. After the sleeve is installed, it is ensured that the bottom surface of the sleeve fits the upper surface of the bottom guard plate body. The bottom guard plate body has a reinforcement installation structure. After the reinforcement is installed, it is ensured that the bottom surface of the reinforcement fits the upper surface of the bottom guard plate body. And they are bonded by foam structural adhesive. The bottom guard plate assembly is connected by bolts and integrated with the water cooling plate and the lower box frame. The bottom guard plate assembly is connected by bolts and integrated with the side mounting assembly. The bottom guard plate is directly integrated with the side mounting assembly, which effectively improves the strength of the side of the battery pack.

[0087] The present invention also provides a vehicle, including the above-mentioned power battery rolled steel lower box integrated structure, which not only reduces the production cost, but also has good sealing performance, ensuring the normal working environment of the battery pack, so that the battery pack can provide sufficient power for the vehicle, and the vehicle can run smoothly and powerfully.

[0088] Example 1

[0089] like Figure 1-Figure 2 As shown, the integrated structure of the lower box of the power battery roll-pressed steel includes a frame assembly, a mounting assembly, a thermal management assembly and a bottom protection assembly. The mounting assembly is integrated with the frame assembly by spot welding to avoid the corrosion risk of arc welding welds of traditional roll-pressed boxes. The thermal management assembly is integrated with the frame assembly by blind rivets. The bottom protection assembly is integrated with the mounting assembly, the thermal management assembly and the frame assembly by bolt connection. The bottom protection assembly is directly integrated with the side mounting assembly.

[0090] like Figure 3 As shown, the frame assembly includes a frame assembly and an internal reinforcement assembly. The frame assembly and the internal reinforcement assembly are integrated by welding. Figure 4-Figure 5 As shown, each section of the profile has a cutting hole on the inner side of the frame assembly, which serves to reduce weight on the one hand and to avoid spot welding holes on the other hand. The lower side of the frame assembly is reserved for openings for blind rivets, with an opening spacing of 85mm and an opening diameter of 5.5mm. The lower side of the frame assembly is reserved for openings for rivet nuts, with an opening spacing of 85mm and an opening diameter of 7.5mm. The openings for blind rivets and rivet nuts are distributed alternately. The frame assembly includes profile 1, profile 2, profile 3, profile 4, profile 5, profile 6, profile 7, and profile 8. The frame assembly is welded and integrated by profile 1, profile 2, profile 3, profile 4, profile 5, profile 6, profile 7, and profile 8. The profiles 1, profile 2, profile 3, profile 4, profile 5, profile 6, profile 7, and profile 8 are of the same cross section and are common molded parts. The material of the profile 1-8 is steel, the cross section is a Japanese-shaped cross section, the cross section width is 30mm, the cross section height is 110mm, and the wall thickness is 1.2mm. The profile 1-8 is formed by roll forming.

[0091] like Figure 6 As shown, the internal reinforcement components include longitudinal beams, front cross beams 1, middle cross beams, front cross beams 2, rear reinforcement plates, front reinforcement plates 1, front reinforcement plates 2, front reinforcement plates 3, and front reinforcement plates 4. The connections between the internal reinforcement components are integrated by welding. The longitudinal beams, front cross beams 1, middle cross beams, and front cross beams 2 are in a U-shaped shape and are formed by a roller pressing process. The material selected is steel, with a cross-sectional width of 35mm, a cross-sectional height of 85mm, and a wall thickness of 1.0mm. The rear reinforcement plate, front reinforcement plate 1, front reinforcement plate 2, front reinforcement plate 3, and front reinforcement plate 4 are in a U-shaped cross-section and are stamped. The material selected is steel, with a cross-sectional width of 35mm, a cross-sectional height of 85mm, and a wall thickness of 1.0mm. The middle cross beam has a middle mounting assembly installation hole. The rear reinforcement plate has a cutting hole, which serves to reduce weight on the one hand and to avoid spot welding holes on the other hand.

[0092] like Figure 7 As shown, the mounting assembly includes a front mounting assembly, a rear mounting assembly, a side mounting assembly, and a middle mounting assembly. Figure 8As shown, the side mount assembly includes a side mount body, a welding nut, a sleeve, and a reinforcement. The side mount assembly is formed separately from the lower box frame. The side mount assembly is integrated with the lower box frame by spot welding. The side mount assembly is connected to the lower box frame by spot welding, avoiding the risk of weld corrosion caused by arc welding. The side mount body is made of high-strength steel with a wall thickness of 1.0mm-2.0mm. The side mount body is formed by stamping. The welding nut is M8, with a distance of 150mm between nuts, and the nut is welded and integrated with the side mount body. The sleeve is made of steel and machined, and the sleeve is integrated with the side mount body by welding, crimping or gluing. The sleeve can also be made of aluminum, machined or die-cast, and the sleeve is integrated with the side mount body by crimping or gluing. The reinforcement is made of high-strength steel, with a square cross-section profile and a wall thickness of 1.2mm. The width is 45mm and the height is 18mm. The reinforcement is integrated below the side mount body by welding. The lower surface of the reinforcement is coated with foam structural adhesive and connected to the bottom guard plate through the foam structural adhesive. The position and number of the reinforcement are determined by the side collision requirements of the vehicle. The number of reinforcements on one side of the battery pack is 1.

[0093] like Fig. 9 As shown, the front mount assembly includes a front mount body and a sleeve. The front mount assembly and the frame assembly are integrated by spot welding. The front mount assembly and the frame assembly are connected by spot welding, which avoids the risk of weld corrosion caused by arc welding. The material of the front mount body is high-strength steel with a wall thickness of 1.5mm. The front mount body is formed by stamping. The material and specifications of the sleeve are consistent with those of the side mount assembly sleeve.

[0094] like Fig.10 As shown, the rear mount assembly includes a front mount body and a sleeve. The rear mount assembly and the frame assembly are integrated by spot welding. The rear mount assembly and the frame assembly are connected by spot welding, which avoids the risk of weld corrosion caused by arc welding. The rear mount body is made of high-strength steel with a wall thickness of 1.5mm. The rear mount body is formed by stamping. The sleeve material and specifications are consistent with the side mount assembly sleeve.

[0095] like Fig.11 As shown, the bottom guard plate assembly includes a bottom guard plate body, a bottom spray material, and a bolt assembly. The bottom guard plate body is made of ultra-high-strength steel with a wall thickness of 1.0 mm, and is stamped or hot-formed ultra-high-strength steel. The bottom guard plate body has a sleeve installation structure. After the sleeve is installed, it is ensured that the bottom surface of the sleeve fits the upper surface of the bottom guard plate body. The bottom guard plate body has a reinforcement member installation structure. After the reinforcement member is installed, it is ensured that the bottom surface of the reinforcement member fits the upper surface of the bottom guard plate body. And they are bonded by foaming structural adhesive. The bottom guard plate assembly is connected by bolts and integrated with the water cooling plate and the lower box frame. The bottom guard plate assembly is connected by bolts and integrated with the side mounting assembly. The bottom guard plate is directly integrated with the side mounting assembly.

[0096] Example 2

[0097] A method for forming a body of a power battery roll-pressed steel lower box integrated structure, comprising the following steps:

[0098] A. Frame component molding:

[0099] A1. Frame roll profile forming: Through the roll-pressing process, it is rolled into a Japanese-shaped cross-section profile, and the splicing interface is welded by laser welding.

[0100] A2. Cutting of profile length: Cut the rolled profiles into corresponding lengths according to the frame component profiles 1, 2, 3, 4, 5, 6, 7 and 8.

[0101] A3. Cutting of profile installation holes: Pre-drill holes for pull rivets, blind rivets, and spot welding according to the corresponding positions of the main frame.

[0102] A4. Profile welding angle cutting: At the profile welding position, make a 45° angle cut. Frame assembly welding.

[0103] A5. Frame assembly welding: Profile 1, Profile 2, Profile 3, Profile 4, Profile 5, Profile 6, Profile 7, and Profile 8 are welded by laser welding.

[0104] A6. The frame assembly is completed.

[0105] A7. Welding of internal reinforcement components and frame components.

[0106] A8. The mounting assembly and the frame assembly are connected by spot welding.

[0107] A9. The thermal management component is connected to the frame component by blind rivets.

[0108] A10. Welding of side mount and reinforcement: The reinforcement is integrated with the side mount by welding.

[0109] A11, the bottom guard plate assembly is integrated with the thermal management assembly and the frame assembly through bolt connection.

[0110] A12. The bottom guard plate assembly and the mounting assembly are integrated by bolt connection.

[0111] A13. The integration of the power battery roll-formed steel lower box is completed.

[0112] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A method for forming a power battery roll-pressed steel lower box integrated structure, characterized in that: The following steps are involved: A frame component molding: A1. Frame roll profile forming: Through the roll-pressing process, it is rolled into a Japanese-shaped cross-section profile, and the splicing interface is welded by laser welding; A2. Cutting of profile length: Cut the rolled profile according to the frame component profile 1, profile 2, profile 3, profile 4, profile 5, profile 6, profile 7, and profile 8; A3. Cutting of profile installation holes: Pre-drill holes for rivets, blind rivets, and spot welding according to the corresponding positions of the main frame; A4. Profile welding angle cutting: profile welding position, 45° angle cutting; frame assembly welding; A5. Frame assembly welding: Profile 1, Profile 2, Profile 3, Profile 4, Profile 5, Profile 6, Profile 7 and Profile 8 are welded by laser welding; A6, frame assembly molding is completed; A7. Welding of internal reinforcement components and frame components; A8. The mounting assembly is spot welded to the frame assembly; A9, the thermal management component is connected to the frame component with blind rivets; A10. Welding of side mount and reinforcement: The reinforcement is integrated with the side mount by welding; A11, the bottom guard plate assembly is integrated with the thermal management assembly and the frame assembly through bolt connection; A12, the bottom guard plate assembly and the mounting assembly are integrated by bolt connection; A13. The integration of the power battery roll-formed steel lower box is completed.

2. A power battery roll-pressed steel lower box integrated structure, characterized in that: It includes a frame assembly, a mounting assembly, a thermal management assembly and a bottom protection assembly; the mounting assembly is integrated with the frame assembly by spot welding; the thermal management assembly is integrated with the frame assembly by blind rivets; the bottom protection assembly is integrated with the mounting assembly, the thermal management assembly and the frame assembly by bolt connection, and the bottom protection assembly is directly integrated with the side mounting assembly; Wherein, the frame assembly includes a frame assembly and an internal reinforcement assembly; the frame assembly and the internal reinforcement assembly are integrated by welding; each section of the profile has a cutting hole on the inner side of the frame assembly, and a blind rivet opening is reserved on the lower side of the frame assembly, and the blind rivet opening and the rivet nut opening are alternately distributed; the internal reinforcement assembly includes a longitudinal beam, a front cross beam 1, a middle cross beam, a front cross beam 2, a rear reinforcement plate, a front reinforcement plate 1, a front reinforcement plate 2, a front reinforcement plate 3 and a front reinforcement plate 4; the connections between the internal reinforcement assemblies are integrated by welding; The mounting assembly comprises a front mounting assembly, a rear mounting assembly, a side mounting assembly and a middle mounting assembly; the side mounting assembly comprises a side mounting body, a welding nut, a sleeve and a reinforcement; the side mounting assembly and the lower box frame are formed separately so that the entire frame mold is shared; the side mounting assembly and the lower box frame are integrated by spot welding, and the side mounting assembly and the lower box frame are connected by spot welding; the front mounting assembly comprises a front mounting body and a sleeve; the front mounting assembly and the frame assembly are integrated by spot welding, and the front mounting assembly and the frame assembly are connected by spot welding; the rear mounting assembly comprises a front mounting body and a sleeve; the rear mounting assembly and the frame assembly are integrated by spot welding, and the rear mounting assembly and the frame assembly are connected by spot welding; The bottom guard plate assembly includes a bottom guard plate body, a bottom spray material and a bolt assembly. The bottom guard plate assembly is connected by bolts and integrated with the side mounting assembly. The bottom guard plate assembly is directly integrated with the side mounting assembly.

3. The integrated structure of the lower box of a power battery made of rolled steel according to claim 2, characterized in that: The opening spacing of the blind rivets is 80-90mm, and the opening diameter is 5-6mm; the lower side of the frame assembly is reserved with rivet nut openings, and the opening spacing of the rivet nut is 80-90mm, and the opening diameter is 7-8mm.

4. The integrated structure of the lower box of a power battery made of rolled steel according to claim 2, characterized in that: The frame assembly includes profile 1, profile 2, profile 3, profile 4, profile 5, profile 6, profile 7, and profile 8; the frame assembly is welded and integrated by profile 1, profile 2, profile 3, profile 4, profile 5, profile 6, profile 7, and profile 8; the profile 1, profile 2, profile 3, profile 4, profile 5, profile 6, profile 7, and profile 8 have the same cross-section and are common mold parts; the material of profiles 1 to 8 is steel, the cross-section is in the shape of a Japanese character, the cross-section width is 25mm-35mm, the cross-section height is 95mm-115mm, and the wall thickness is 0.8-1.5mm; the profiles 1 to 8 are formed by roller pressing.

5. The integrated structure of the lower box of a power battery made of rolled steel according to claim 2, characterized in that: The longitudinal beam, front cross beam 1, middle cross beam and front cross beam 2 adopt a U-shaped or a S-shaped cross section and are formed by a rolling process; the material is steel, the cross section width is 25mm-45mm, the cross section height is 75mm-95mm, and the wall thickness is 0.8-1.5mm; the rear reinforcement plate, front reinforcement plate 1, front reinforcement plate 2, front reinforcement plate 3 and front reinforcement plate 4 adopt a U-shaped cross section and are formed by stamping; the material is steel, the cross section width is 25mm-45mm, the cross section height is 75mm-95mm, and the wall thickness is 0.8-1.5mm; the middle cross beam has a middle mounting component installation hole; the rear reinforcement plate has a cutting hole.

6. The integrated structure of the lower box of a power battery made of rolled steel according to claim 2, characterized in that: The side mount body is made of high-strength steel with a wall thickness of 1.0mm-2.0mm; the side mount body is formed by stamping; the welding nut is M6 or M8, the distance between nuts is 100mm-200mm, and the nut is welded and integrated with the side mount body.

7. The integrated structure of the lower box of a power battery made of rolled steel according to claim 2, characterized in that: The reinforcement is made of high-strength steel with a U-shaped cross-section profile, a wall thickness of 1.0mm-2.0mm, a width of 40mm-50mm, and a height of 15mm-20mm. The reinforcement is integrated under the side mount body by welding. The lower surface of the reinforcement is coated with foamed structural adhesive and connected to the bottom guard plate through the foamed structural adhesive. The position and number of the reinforcements are determined by the side collision requirements of the entire vehicle. The number of reinforcements on a single side of the battery pack is 1-3.

8. The integrated structure of the lower box of a power battery made of rolled steel according to claim 2, characterized in that: The front mount body is made of high-strength steel with a wall thickness of 1.0mm-2.0mm; the front mount body is formed by stamping; the sleeve material and specifications are consistent with the side mount assembly sleeve; the rear mount body is made of high-strength steel with a wall thickness of 1.0mm-2.0mm; the rear mount body is formed by stamping; the sleeve material and specifications are consistent with the side mount assembly sleeve.

9. The integrated structure of the lower box of a power battery made of rolled steel according to claim 2, characterized in that: The bottom guard plate body has a sleeve installation structure. After the sleeve is installed, it is ensured that the bottom surface of the sleeve is in contact with the upper surface of the bottom guard plate body; the bottom guard plate body has a reinforcement installation structure. After the reinforcement is installed, it is ensured that the bottom surface of the reinforcement is in contact with the upper surface of the bottom guard plate body and they are bonded together by foam structural adhesive; the bottom guard plate assembly is connected by bolts and integrated with the water cooling plate and the lower box frame.

10. A vehicle, characterized in that: It includes a power battery rolled steel lower box integrated structure as described in claims 2 to 9.

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