Water-cooled battery box applying FSW welding technology

Abstract

The invention belongs to the technical field of battery box body welding, and discloses a water-cooling battery box body applying an FSW welding technology, the water-cooling battery box body comprises an aluminum alloy box body, the aluminum alloy box body comprises an upper shell, a lower shell, a fixed side skirt and a predetermined welding groove, the upper shell and the lower shell are symmetrically arranged up and down, and the upper shell and the lower shell are symmetrically arranged up and down; a fixed side skirt is integrally formed on the outer side faces of the ends, close to each other, of the upper shell and the lower shell. According to the method, the battery box is fixed through the clamp made of steel, the bolts and the positioning pins, displacement in the welding process is effectively prevented, the welding precision and stability are guaranteed, meanwhile, fine adjustment is conducted on welding parameter setting, including the rotating speed of a welding tool, the feeding speed, the diameter of the tool, the shoulder width of the tool and the like, and welding quality is improved. Therefore, the uniformity of the welding process and the quality of a welded joint are ensured. In the welding process, preheating treatment and reasonable welding sequence and welding position planning are adopted, and the welding efficiency and the joint quality are further improved.

Description

Technical Field

[0001] The invention belongs to the technical field of battery case welding, and in particular relates to a water-cooled battery case using FSW welding technology. Background Art

[0002] A water-cooled battery box is a box that uses water cooling technology to cool the battery. It mainly circulates the coolant in the cooling channel inside the battery box to take away the heat generated by the battery, thereby reducing the battery temperature and improving the battery's working efficiency and service life. Conventional water-cooled boxes are mainly made of metal, mainly steel plates or aluminum alloys and other metal materials. During the processing process, welding is required to connect the upper and lower shells.

[0003] The welding methods of battery cases mainly include arc welding (such as MIG, CMT), etc. Arc welding is a method of melting and connecting welding materials through the high temperature generated by the arc. MIG welding and CMT welding are two common forms of arc welding. They have high efficiency and stability in battery case welding, but there are still certain shortcomings when using conventional welding methods to weld battery cases. For example, the heat generated by the arc in conventional welding methods is relatively high. Since arc welding is a local heating welding method, welding deformation and residual stress are easily generated during the welding process. These deformations and stresses may have an adverse effect on the dimensional accuracy and performance of the battery case, and improvements are urgently needed. Summary of the invention

[0004] The purpose of the present invention is to provide a water-cooled battery case using FSW welding technology to solve the problems raised in the above background technology.

[0005] In order to achieve the above-mentioned object, the present invention provides the following technical solutions: a water-cooled battery box body using FSW welding technology, comprising an aluminum alloy box body, the aluminum alloy box body comprising an upper shell body, a lower shell body, a fixed side skirt, and a predetermined welding groove, the upper shell body and the lower shell body are symmetrically arranged up and down, the outer side surfaces of the upper shell body and the lower shell body relatively close to one end are integrally formed with a fixed side skirt, the upper and lower fixed side skirts are welded and fixed, and the outer side surfaces of the fixed side skirts are provided with a predetermined welding groove;

[0006] Special fixed side skirts are provided for fixed welding between the upper shell and the lower shell to avoid direct force on the upper shell and the lower shell. Special predetermined welding grooves are provided to ensure that welding can be carried out according to a predetermined path, thereby ensuring welding uniformity and avoiding the problem of uneven welds.

[0007] It also includes the following welding processes for water-cooled battery boxes:

[0008] S1: Material preparation;

[0009] S2: welding equipment setup;

[0010] S3: welding parameter setting;

[0011] S4: welding process;

[0012] S5: cooling control;

[0013] S6: welding quality inspection;

[0014] S7: Post-processing.

[0015] The entire welding process covers key steps such as material preparation, equipment setting, parameter setting, actual welding, cooling control, quality inspection and post-processing to ensure the efficiency, accuracy and safety of the welding process. This welding technology not only improves the overall strength and sealing of the water-cooled battery box, but also significantly improves production efficiency and product quality, providing a strong guarantee for the stable operation of the battery system.

[0016] As a further technical solution of the present invention, the material preparation includes using 6061 aluminum alloy with a thickness of 3 mm to 5 mm and performing surface treatment, including using acetone to remove surface oil stains and using a polishing machine to grind the welding area to remove the oxide layer.

[0017] During the material preparation stage, 6061 aluminum alloy is used as the main material for the water-cooled battery box, and its thickness is controlled between 3mm and 5mm to ensure the strength and lightness of the box. At the same time, the surface of the aluminum alloy is carefully treated, acetone is used to effectively remove oil stains, and then the welding area is carefully polished with a polishing machine to completely remove the oxide layer, laying a solid foundation for subsequent welding work and ensuring welding quality and box performance.

[0018] As a further technical solution of the present invention, the welding equipment setting includes using a CNC FSW welding machine to ensure high-precision control, and using steel to manufacture a fixture, and fixing the battery box with bolts and locating pins to ensure that it does not move during the welding process.

[0019] The welding equipment setting link is crucial. By selecting a CNC FSW welding machine, high-precision welding control can be achieved. At the same time, the fixture is made of solid steel, and the battery box is firmly fixed with bolts and locating pins. This measure can ensure that the box remains absolutely stable during the welding process and avoids any displacement, providing a strong guarantee for the accuracy and quality of welding.

[0020] As a further technical solution of the present invention, the welding parameter setting includes setting the welding tool rotation speed to 800rpm to 1200rpm, and adjusting it according to the material thickness, and setting the feed speed to 60mm / min to 80mm / min to ensure a uniform welding process, including using tungsten alloy to make a welding tool, the tool diameter is controlled to 6mm to 8mm, and the tool shoulder width is controlled to 1.5mm to 2mm.

[0021] Welding parameter setting is the key to ensure welding quality. According to the material characteristics and thickness of 6061 aluminum alloy, the rotation speed of the welding tool is carefully set at 800 to 1200 revolutions per minute, the feed speed is 60 to 80 mm per minute, and the welding tool made of tungsten alloy with a diameter of 6 to 8 mm and a shoulder width of 1.5 to 2 mm is selected to ensure the uniformity and stability of the welding process, thereby obtaining high-quality welded joints.

[0022] As a further technical solution of the present invention, the welding process includes preheating treatment, welding sequence, and welding position. The preheating treatment includes heating the welding area to 100°C to 150°C by using magnetic attraction and a bottom heating plate. The welding sequence includes path planning, that is, using a "Z"-shaped welding path, welding section by section, and the length of each welding section is controlled at 300mm to 500mm. The welding position includes starting welding from one end of the battery case and advancing to the other end along a preset path.

[0023] The welding process covers several key links such as preheating treatment, welding sequence and welding position. By using magnetic attraction and bottom heating plate, the welding area is preheated to 100℃ to 150℃ to reduce welding deformation. In terms of welding sequence, we carefully planned a "Z" shaped path and welded it section by section. The length of each section was controlled at 300 to 500 mm to ensure the welding quality. At the same time, starting from one end of the battery box, we steadily advanced along the preset path to the other end, ensuring the continuity and consistency of the welding, thereby improving the efficiency of the entire welding process and the quality of the welded joints.

[0024] As a further technical solution of the present invention, the cooling control includes using natural cooling to avoid forced cooling, and subsequent processing can only be carried out after the temperature of the welding joint drops to room temperature, about 25°C.

[0025] Cooling control is an important step in post-welding processing. We use natural cooling and patiently wait for the temperature of the welded joint to slowly drop to room temperature (about 25°C) to avoid the negative effects that may be caused by forced cooling, such as thermal stress and embrittlement of the welded joint. This step ensures the stability and reliability of the welded joint, laying a solid foundation for subsequent processing, assembly and use.

[0026] As a further technical solution of the present invention, the welding quality inspection includes visual inspection, ultrasonic inspection, and tensile test. The visual inspection includes inspecting the welding surface to confirm that there are no cracks, pores or other obvious defects. The ultrasonic inspection includes using an ultrasonic flaw detector to detect internal defects in the weld to ensure that there are no pores and inclusions. The tensile test includes preparing a tensile specimen based on the weld joint, and using a material testing machine to perform a tensile test, recording the maximum tensile force and the fracture position.

[0027] Welding quality inspection is a key link to ensure the quality of welded joints. The quality of welded joints is comprehensively evaluated by using a variety of methods such as visual inspection, ultrasonic testing and tensile testing. Visual inspection can intuitively find obvious defects such as cracks and pores on the weld surface; ultrasonic testing can penetrate deep into the weld to detect potential pores and inclusions; tensile testing prepares tensile specimens, uses a material testing machine to stretch, records the maximum tensile force and fracture position, and further verifies the strength and reliability of the welded joint. These testing methods together constitute a complete system for welding quality inspection.

[0028] As a further technical solution of the present invention, the post-treatment includes heat treatment and surface treatment. The heat treatment includes aging treatment, the temperature is controlled at 160°C, and the time is 8 hours. The surface treatment includes anodizing and surface cleaning. The anodizing is performed on the welding area to improve corrosion resistance. The surface cleaning is performed by rinsing with clean water to remove surface residues and storing after drying.

[0029] Post-processing is an important part of quality assurance for welded parts. Heat treatment includes aging treatment to ensure that welded parts are stable at 160°C for 8 hours to reduce residual stress and improve material stability. Surface treatment uses anodizing technology to perform special treatment on the welding area to enhance its corrosion resistance. At the same time, clean water is used to remove surface residues and dry the welded parts to ensure the cleanliness of the surface. This series of post-processing processes aims to improve the overall quality and performance of welded parts and provide strong guarantees for subsequent storage and use.

[0030] The beneficial effects of the present invention are as follows:

[0031] 1. The present invention adopts FSW, i.e. friction stir welding technology, which effectively solves the welding deformation and residual stress problems caused by arc heat in conventional welding methods. FSW technology utilizes the high-speed rotation of the stirring head in the welding material and the principle of frictional heat generation to achieve plastic flow and connection of the material. This process does not require filling materials, and the welding temperature is relatively low, thereby greatly reducing the generation of welding deformation and residual stress. The surface oil is removed by acetone and the welding area is polished by a polishing machine to remove the oxide layer, further improving the quality of the welded joint. In terms of welding equipment settings, the present invention adopts a CNC FSW welding machine to ensure high-precision control, and fixes the battery box body by steel manufacturing fixtures and bolts and locating pins, effectively preventing displacement during welding, ensuring welding accuracy and stability, and finely adjusting the welding parameter settings, including welding tool speed, feed speed, tool diameter and tool shoulder width, etc., to ensure the uniformity of the welding process and the quality of the welded joint. During the welding process, the present invention also adopts preheating treatment, reasonable welding sequence and welding position planning to further improve welding efficiency and joint quality.

[0032] 2. The present invention avoids the negative effects that may be caused by forced cooling, such as thermal stress, embrittlement of welded joints, etc., by adopting a natural cooling method, thereby ensuring the stability and reliability of welded joints. At the same time, the present invention also carries out strict welding quality inspections, including visual inspection, ultrasonic inspection and tensile testing, to comprehensively evaluate the quality of welded joints. Visual inspection can intuitively find obvious defects such as cracks and pores on the welding surface; ultrasonic inspection can penetrate deep into the weld to detect potential pores and inclusions; the tensile test prepares tensile specimens, uses a material testing machine to stretch, records the maximum tensile force and fracture position, further verifies the strength and reliability of the welded joint, and also performs heat treatment and surface treatment. Aging treatment effectively reduces the residual stress in the welded joint by controlling the temperature and time, and improves the stability and service life of the material. Anodizing treatment further improves the corrosion resistance of the welding area, enabling it to better adapt to complex use environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is an overall schematic diagram of the battery box of the present invention;

[0034] Figure 2 It is an exploded schematic diagram of the upper shell and the lower shell structure of the present invention;

[0035] Figure 3 A separate schematic diagram of a predetermined welding groove structure of the present invention;

[0036] Figure 4 It is the overall block diagram of the welding process of the present invention;

[0037] Figure 5It is an overall block diagram of the welding process of the present invention;

[0038] Figure 6 It is the overall block diagram of welding quality detection of the present invention;

[0039] Figure 7 It is the overall block diagram of the post-processing of the present invention.

[0040] In the figure: 1, aluminum alloy box body; 101, upper shell; 102, lower shell; 103, fixed side skirt; 104, predetermined welding groove. DETAILED DESCRIPTION

[0041] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0042] like Figures 1 to 7 As shown, in an embodiment of the present invention, a water-cooled battery case using FSW welding technology includes an aluminum alloy case 1, the aluminum alloy case 1 includes an upper shell 101, a lower shell 102, a fixed side skirt 103, and a predetermined welding groove 104, the upper shell 101 and the lower shell 102 are symmetrically arranged up and down, the outer side surfaces of the upper shell 101 and the lower shell 102 relatively close to one end are integrally formed with a fixed side skirt 103, the upper and lower fixed side skirts 103 are welded and fixed, and the outer side surface of the fixed side skirt 103 is provided with a predetermined welding groove 104;

[0043] A dedicated fixed side skirt 103 is provided for fixed welding between the upper shell 101 and the lower shell 102, and the fixed side skirt 103 is used to avoid direct force on the upper shell 101 and the lower shell 102. At the same time, a dedicated predetermined welding groove 104 is provided to ensure that welding can be carried out according to a predetermined path, ensure welding uniformity, and avoid the problem of uneven welds.

[0044] It also includes the following welding processes for water-cooled battery boxes:

[0045] S1: Material preparation;

[0046] S2: welding equipment setup;

[0047] S3: welding parameter setting;

[0048] S4: welding process;

[0049] S5: cooling control;

[0050] S6: welding quality inspection;

[0051] S7: Post-processing.

[0052] The entire welding process covers key steps such as material preparation, equipment setting, parameter setting, actual welding, cooling control, quality inspection and post-processing to ensure the efficiency, accuracy and safety of the welding process. This welding technology not only improves the overall strength and sealing of the water-cooled battery box, but also significantly improves production efficiency and product quality, providing a strong guarantee for the stable operation of the battery system.

[0053] Among them, material preparation includes using 6061 aluminum alloy with a thickness of 3mm to 5mm and surface treatment, including using acetone to remove surface oil stains and using a polishing machine to grind the welding area to remove the oxide layer.

[0054] During the material preparation stage, 6061 aluminum alloy is used as the main material for the water-cooled battery box, and its thickness is controlled between 3mm and 5mm to ensure the strength and lightness of the box. At the same time, the surface of the aluminum alloy is carefully treated, acetone is used to effectively remove oil stains, and then the welding area is carefully polished with a polishing machine to completely remove the oxide layer, laying a solid foundation for subsequent welding work and ensuring welding quality and box performance.

[0055] Among them, the welding equipment setting includes the use of CNC FSW welding machines to ensure high-precision control, and the use of steel to manufacture fixtures, and the battery box is fixed with bolts and locating pins to ensure that it does not move during the welding process.

[0056] The welding equipment setting link is crucial. By selecting a CNC FSW welding machine, high-precision welding control can be achieved. At the same time, the fixture is made of solid steel, and the battery box is firmly fixed with bolts and locating pins. This measure can ensure that the box remains absolutely stable during the welding process and avoids any displacement, providing a strong guarantee for the accuracy and quality of welding.

[0057] Among them, the welding parameter setting includes setting the welding tool speed to 800rpm to 1200rpm, and adjusting it according to the material thickness, and setting the feed speed to 60mm / min to 80mm / min to ensure a uniform welding process, including using tungsten alloy to make welding tools, the tool diameter is controlled to 6mm to 8mm, and the tool shoulder width is controlled to 1.5mm to 2mm.

[0058] Welding parameter setting is the key to ensure welding quality. According to the material characteristics and thickness of 6061 aluminum alloy, the rotation speed of the welding tool is carefully set at 800 to 1200 revolutions per minute, the feed speed is 60 to 80 mm per minute, and the welding tool made of tungsten alloy with a diameter of 6 to 8 mm and a shoulder width of 1.5 to 2 mm is selected to ensure the uniformity and stability of the welding process, thereby obtaining high-quality welded joints.

[0059] Among them, the welding process includes preheating treatment, welding sequence, and welding position. The preheating treatment includes heating the welding area to 100°C to 150°C by using magnetic attraction and a bottom heating plate. The welding sequence includes path planning, that is, using a "Z" shaped welding path, welding section by section, and the length of each welding section is controlled at 300mm to 500mm. The welding position includes starting welding from one end of the battery case and advancing along the preset path to the other end.

[0060] The welding process covers several key links such as preheating treatment, welding sequence and welding position. By using magnetic attraction and bottom heating plate, the welding area is preheated to 100℃ to 150℃ to reduce welding deformation. In terms of welding sequence, we carefully planned a "Z" shaped path and welded it section by section. The length of each section was controlled at 300 to 500 mm to ensure the welding quality. At the same time, starting from one end of the battery box, we steadily advanced along the preset path to the other end, ensuring the continuity and consistency of the welding, thereby improving the efficiency of the entire welding process and the quality of the welded joints.

[0061] Among them, cooling control includes using natural cooling methods, avoiding forced cooling methods, and waiting for the temperature of the welding joint to drop to room temperature, about 25°C, before subsequent processing can be carried out.

[0062] Cooling control is an important step in post-welding processing. We use natural cooling and patiently wait for the temperature of the welded joint to slowly drop to room temperature (about 25°C) to avoid the negative effects that may be caused by forced cooling, such as thermal stress and embrittlement of the welded joint. This step ensures the stability and reliability of the welded joint, laying a solid foundation for subsequent processing, assembly and use.

[0063] Among them, welding quality inspection includes visual inspection, ultrasonic inspection, and tensile test. Visual inspection includes inspecting the welding surface to confirm that there are no cracks, pores or other obvious defects. Ultrasonic inspection includes using an ultrasonic flaw detector to detect internal defects in the weld to ensure that there are no pores and inclusions. Tensile test includes preparing tensile specimens according to the weld joint, and using a material testing machine to perform tensile test, recording the maximum tensile force and fracture position.

[0064] Welding quality inspection is a key link to ensure the quality of welded joints. The quality of welded joints is comprehensively evaluated by using a variety of methods such as visual inspection, ultrasonic testing and tensile testing. Visual inspection can intuitively find obvious defects such as cracks and pores on the weld surface; ultrasonic testing can penetrate deep into the weld to detect potential pores and inclusions; tensile testing prepares tensile specimens, uses a material testing machine to stretch, records the maximum tensile force and fracture position, and further verifies the strength and reliability of the welded joint. These testing methods together constitute a complete system for welding quality inspection.

[0065] Among them, post-treatment includes heat treatment and surface treatment. Heat treatment includes aging treatment, the temperature is controlled at 160°C, and the time is 8 hours. Surface treatment includes anodizing and surface cleaning. Anodizing is performed on the welding area to improve corrosion resistance. Surface cleaning uses clean water to remove surface residues and store after drying.

[0066] Post-processing is an important part of quality assurance for welded parts. Heat treatment includes aging treatment to ensure that welded parts are stable at 160°C for 8 hours to reduce residual stress and improve material stability. Surface treatment uses anodizing technology to perform special treatment on the welding area to enhance its corrosion resistance. At the same time, clean water is used to remove surface residues and dry the welded parts to ensure the cleanliness of the surface. This series of post-processing processes aims to improve the overall quality and performance of welded parts and provide strong guarantees for subsequent storage and use.

[0067] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A water-cooled battery box using FSW welding technology, comprising an aluminum alloy box (1), characterized in that: The aluminum alloy box (1) comprises an upper shell (101), a lower shell (102), a fixed side skirt (103), and a predetermined welding groove (104); the upper shell (101) and the lower shell (102) are symmetrically arranged up and down; the fixed side skirt (103) is integrally formed on the outer side surfaces of the upper shell (101) and the lower shell (102) relatively close to one end; the upper and lower fixed side skirts (103) are welded and fixed; and the outer side surface of the fixed side skirt (103) is provided with a predetermined welding groove (104); It also includes the following welding processes for water-cooled battery boxes: S1: Material preparation; S2: welding equipment setup; S3: welding parameter setting; S4: welding process; S5: cooling control; S6: welding quality inspection; S7: Post-processing.

2. According to claim 1, a water-cooled battery box using FSW welding technology is characterized in that: The material preparation includes using 6061 aluminum alloy with a thickness of 3 mm to 5 mm and performing surface treatment, including using acetone to remove surface oil stains and using a polishing machine to grind the welding area to remove the oxide layer.

3. According to claim 1, a water-cooled battery box using FSW welding technology is characterized in that: The welding equipment setup includes using a CNC FSW welding machine to ensure high-precision control, using steel to manufacture fixtures, and fixing the battery box with bolts and locating pins to ensure that it does not move during the welding process.

4. A water-cooled battery box using FSW welding technology according to claim 1, characterized in that: The welding parameter setting includes setting the welding tool rotation speed to 800rpm to 1200rpm, adjusting it according to the material thickness, and setting the feed speed to 60mm / min to 80mm / min to ensure a uniform welding process, including using tungsten alloy to make the welding tool, controlling the tool diameter to 6mm to 8mm, and controlling the tool shoulder width to 1.5mm to 2mm.

5. The water-cooled battery box using FSW welding technology according to claim 1, characterized in that: The welding process includes preheating treatment, welding sequence, and welding position. The preheating treatment includes heating the welding area to 100°C to 150°C by using magnetic attraction and a bottom heating plate. The welding sequence includes path planning, that is, using a "Z" shaped welding path, welding section by section, and the length of each welding section is controlled at 300mm to 500mm. The welding position includes starting welding from one end of the battery box and advancing to the other end along a preset path.

6. The water-cooled battery box using FSW welding technology according to claim 1, characterized in that: The cooling control includes using natural cooling and avoiding forced cooling, and it is necessary to wait for the temperature of the welding joint to drop to room temperature, about 25° C., before subsequent processing can be carried out.

7. The water-cooled battery box using FSW welding technology according to claim 1, characterized in that: The welding quality inspection includes visual inspection, ultrasonic inspection and tensile test. The visual inspection includes inspecting the welding surface to confirm that there are no cracks, pores or other obvious defects. The ultrasonic inspection includes using an ultrasonic flaw detector to detect internal defects in the weld to ensure that there are no pores and inclusions. The tensile test includes preparing tensile specimens according to the weld joint, and using a material testing machine to perform a tensile test, recording the maximum tensile force and the fracture position.

8. The water-cooled battery box using FSW welding technology according to claim 1, characterized in that: The post-treatment includes heat treatment and surface treatment. The heat treatment includes aging treatment with the temperature controlled at 160°C for 8 hours. The surface treatment includes anodizing and surface cleaning. The anodizing treatment is performed on the welding area to improve corrosion resistance. The surface cleaning is performed by washing with clean water to remove surface residues and storing after drying.

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