Battery pack cooling block manufacturing method and battery pack cooling block manufactured by the same

Abstract

The present invention relates to a method for manufacturing a cooling block for a vehicle battery pack and a cooling block for a vehicle battery pack manufactured by the method. The method for manufacturing a cooling block for a vehicle battery pack according to the present invention comprises: a cooling block upper plate preparation step for preparing a cooling block upper plate, which is one side of the vehicle battery pack cooling block; a cooling block lower plate preparation step for preparing a cooling block lower plate to be welded and integrated with the cooling block upper plate; a cooling block upper plate and a cooling block lower plate contact surface arrangement step for arranging the cooling block upper plate and the cooling block lower plate so that a cooling water flow path is formed between the cooling block upper plate and the cooling block lower plate, through which cooling water flows; a welding position selection step for selecting a welding position between the cooling block upper plate and the cooling block lower plate arranged in contact surfaces; and a laser hybrid welding step for performing welding through a predetermined laser hybrid welding along the selected welding position so that the cooling block upper plate and the cooling block lower plate are integrated into a single body.

Description

Technology Field

[0001] The present invention relates to a method for manufacturing a cooling block for a vehicle battery pack and a cooling block for a vehicle battery pack manufactured by the same method. More specifically, the invention relates to a method for manufacturing a cooling block for a vehicle battery pack and a cooling block for a vehicle battery pack manufactured by the same method, wherein the upper and lower plates of the cooling block are welded together using a laser hybrid welding method different from conventional methods, thereby ensuring watertightness through defect-free welding, and furthermore, eliminating the phenomenon of fire or equipment failure caused by leakage of cooling water due to welding defects. Background Technology

[0002] Hybrid electric vehicles, fuel cell vehicles, and electric vehicles are all vehicles powered by electric motors.

[0003] These vehicles are necessarily equipped with a high-voltage battery pack that provides driving power to the electric motor. The high-voltage battery pack is configured to supply the necessary power by repeatedly charging and discharging during vehicle operation.

[0004] A conventional high-voltage battery pack includes a battery case, a plurality of battery modules mounted within the battery case, and a Battery Management System (BMS) that detects the voltage, current, and temperature of each unit cell constituting the battery module and controls its operation.

[0005] Battery cases are typically made of steel, aluminum, or stainless steel. While steel battery cases offer the advantages of lower cost and higher strength compared to aluminum or stainless steel, they have the disadvantages of being heavy and negatively impacting fuel efficiency. Consequently, the use of aluminum or stainless steel battery cases has recently been increasing, as they offer high thermal conductivity and allow for weight reduction to achieve lightweight design and improved fuel efficiency.

[0006] The temperature of high-voltage battery packs continuously rises due to heat generation during charging and discharging. If the battery temperature rises excessively, it causes performance degradation and shortens its lifespan, and in severe cases, poses a risk of fire.

[0007] Therefore, high-voltage battery packs are essentially equipped with a cooling device, namely a cooling block, to cool the battery to an appropriate temperature. This cooling block serves to dissipate heat from the high-voltage battery pack by cooling the battery case.

[0008] Meanwhile, regarding the application of cooling blocks, examples include air-cooled devices that use air and water-cooled devices that use cooling water; it is known that water-cooled devices exhibit better cooling efficiency than air-cooled devices.

[0009] These cooling blocks cool the battery case by creating passages for coolant to flow through the upper and lower plates of a block with a specific shape.

[0010] At this time, if pressure is applied to the cooling block due to vibration or external force, causing the upper and lower plates of the cooling block to detach, or if leakage occurs due to welding defects during manufacturing, the cooling water flowing inside the upper and lower plates of the block may leak out and penetrate the battery, potentially causing a fire or malfunction. Therefore, airtightness, or watertightness, is required when manufacturing the cooling block.

[0011] However, currently, it is common practice to perform furnace brazing by placing the entire cooling block into an electric furnace. Considering that this is practically an unrealistic technology from the perspective of realizing mass production, there is a need to develop new technology to complement it. Prior art literature

[0012] Korean Intellectual Property Office Application No. 10-2018-0036957 The problem to be solved

[0013] The objective of the present invention is to provide a method for manufacturing a cooling block for a vehicle battery pack and a cooling block for a vehicle battery pack manufactured by the same, which can ensure watertightness through defect-free welding by welding and joining the upper and lower plates of the cooling block using a laser hybrid welding method different from conventional methods, and further eliminate phenomena that cause fire or equipment failure due to leakage of cooling water caused by welding defects. means of solving the problem

[0014] The above objective is achieved by a method for manufacturing a cooling block for a vehicle battery pack, characterized by comprising: a cooling block upper plate preparation step for preparing a cooling block upper plate, which is one side of the cooling block for a vehicle battery pack; a cooling block lower plate preparation step for preparing a cooling block lower plate to be welded and integrated with the cooling block upper plate; a cooling block upper plate and a cooling block lower plate contact surface arrangement step for arranging the cooling block upper plate and the cooling block lower plate so that a cooling water flow path is formed between the cooling block upper plate and the cooling block lower plate, through which cooling water flows; a welding position selection step for selecting a welding position of the cooling block upper plate and the cooling block lower plate arranged in contact surfaces; and a laser hybrid welding step for performing welding through a predetermined laser hybrid welding along the selected welding position so that the cooling block upper plate and the cooling block lower plate are integrated into one body.

[0015] After performing the laser hybrid welding step described above, the method further includes a welding quality inspection step for determining the quality of the product by inspecting the welded portions of the upper plate of the cooling block and the lower plate of the cooling block, and the upper plate of the cooling block preparation step and the lower plate of the cooling block preparation step can proceed independently in parallel.

[0016] The above objective is also achieved by a vehicle battery pack cooling block comprising: a cooling block top plate forming one side of the vehicle battery pack cooling block; and a cooling block bottom plate integrated into one body with the cooling block top plate through welding so as to form a cooling water channel through which cooling water flows between them, wherein the cooling block top plate and the cooling block bottom plate are welded by laser hybrid welding to integrate into one body.

[0017] In order to form the above cooling water flow path, a flow path upper plate portion is formed on the upper plate of the cooling block and a flow path lower plate portion is formed on the lower plate of the cooling block, wherein a plurality of flow path branching protrusions are formed on the lower plate portion of the flow path to branch the direction of the cooling water flow path in multiple directions, and the thickness of the upper plate of the cooling block may be manufactured to be thicker than the thickness of the lower plate of the cooling block. Effects of the invention

[0018] According to the present invention, by welding and joining the upper and lower plates of a cooling block using a laser hybrid welding method different from conventional methods, watertightness can be ensured through defect-free welding, and furthermore, the phenomenon of fire or equipment failure caused by leakage of cooling water due to welding defects can be eliminated. Brief explanation of the drawing

[0019] FIG. 1 is a flowchart of a method for manufacturing a cooling block for a vehicle battery pack according to a first embodiment of the present invention. FIGS. 2 to 7 are step-by-step process diagrams according to the manufacturing method of FIG. 1. FIG. 8 is a drawing of a vehicle battery pack cooling block manufactured by the method for manufacturing a vehicle battery pack cooling block of FIG. 1. FIGS. 9 and FIGS. 10 are process diagrams of key parts of a method for manufacturing a cooling block for a vehicle battery pack according to a second embodiment of the present invention. FIG. 11 is a process diagram of the main parts of a method for manufacturing a cooling block for a vehicle battery pack according to a third embodiment of the present invention. Specific details for implementing the invention

[0020] The advantages and features of the present invention and the methods for achieving them will become clear by referring to the embodiments described below in detail together with the accompanying drawings.

[0021] However, the present invention is not limited to the embodiments disclosed below but will be implemented in various different forms.

[0022] In this specification, the embodiments are provided to make the disclosure of the invention complete and to fully inform those skilled in the art of the scope of the invention. The invention is defined only by the scope of the claims.

[0023] Accordingly, in some embodiments, well-known components, well-known operations, and well-known techniques are not specifically described to avoid the invention being interpreted ambiguously.

[0024] Throughout the specification, the same reference numerals refer to the same components. Furthermore, the terms used (mentioned) in this specification are for describing the embodiments and are not intended to limit the invention.

[0025] In this specification, the singular form includes the plural form unless specifically stated otherwise in the text. Additionally, components and actions (operations) referred to as 'comprising (or having)' do not exclude the presence or addition of one or more other components and actions.

[0026] Unless otherwise defined, all terms used in this specification (including technical and scientific terms) may be used in a meaning that is commonly understood by those skilled in the art to which the present invention belongs.

[0027] Furthermore, terms defined in commonly used dictionaries are not interpreted ideally or excessively unless otherwise defined.

[0028] This invention was developed based on the following national project.

[0029] 1. Research Management Agency: Gyeongbuk Embedded Research Institute

[0030] 2. Research Project Name: Future Automotive Parts Conversion Corporate R&D Project

[0031] 3. Research Project Title: Development of Stainless Steel Battery Case Manufacturing Technology for Next-Generation EV Commercial Vehicle Platforms

[0032] 4. Contribution Rate: 1:1

[0033] 5. Organizing Agency: Sewon E&I Co., Ltd.

[0034] 6. Study Period: August 1, 2024 – March 31, 2025 (※8 months)

[0035] Hereinafter, preferred embodiments of the present invention will be described with reference to the attached drawings.

[0036] FIG. 1 is a flowchart of a method for manufacturing a vehicle battery pack cooling block according to a first embodiment of the present invention, FIG. 2 to 7 are step-by-step process diagrams according to the method of FIG. 1, and FIG. 8 is a drawing of a vehicle battery pack cooling block manufactured by the method for manufacturing a vehicle battery pack cooling block of FIG. 1.

[0037] With reference to these drawings, the present invention ensures watertightness through defect-free welding by welding and joining the upper and lower plates (110, 120) of a cooling block using a laser hybrid welding method different from conventional methods, and furthermore, eliminates the phenomenon of fire or equipment failure caused by leakage of cooling water due to welding defects.

[0038] The present invention, which can provide such effects, may be applied to the method for manufacturing a vehicle battery pack cooling block of FIG. 1 and the vehicle battery pack cooling block (100) of FIG. 8.

[0039] First, a method for manufacturing a cooling block for a vehicle battery pack according to one embodiment of the present invention is described. The method for manufacturing a cooling block for a vehicle battery pack according to this embodiment may include a step of preparing an upper plate of the cooling block (S110), a step of preparing a lower plate of the cooling block (S120), a step of arranging the contact surfaces of the upper and lower plates of the cooling block (S130), a step of selecting a welding location (S140), a laser hybrid welding step (S150), and a welding quality inspection step (S160).

[0040] The cooling block top plate preparation step (S110) is a process of preparing a cooling block top plate (110), which is one side of a vehicle battery pack cooling block (100), as shown in FIGS. 1 and 2.

[0041] The cooling block bottom plate preparation step (S120) is a process of preparing a cooling block bottom plate (130) to be welded and integrated with the cooling block top plate (110) as shown in FIGS. 1 and 3. At this time, the cooling block top plate preparation step (S110) and the cooling block bottom plate preparation step (S120) can proceed independently in parallel. That is, either one can be performed first.

[0042] The step of arranging the upper and lower plates of the cooling block in contact (S130) is a process of arranging the upper plate (110) and the lower plate (130) of the cooling block in contact so that a cooling water channel (120) through which cooling water flows is formed between the upper plate (110) and the lower plate (130) of the cooling block as shown in FIGS. 1 and FIGS. 4.

[0043] The welding position selection step (S140) is a process of selecting the welding position (140) of the upper cooling block plate (110) and the lower cooling block plate (130) arranged in contact surfaces as in FIGS. 1 and FIGS. 5. The welding position (140) may be directly marked, or only the position may be determined according to a program.

[0044] The laser hybrid welding step (S150) is a process in which welding is performed by a laser hybrid welding device (150) along selected welding positions (140) as shown in FIGS. 1 and 6, so that the upper plate (110) of the cooling block and the lower plate (130) of the cooling block are integrated into one body.

[0045] Here, laser hybrid welding is a welding method that combines laser welding and arc welding, providing both the advantages of laser welding and arc welding. In particular, laser hybrid welding compensates for the disadvantages of each welding method by combining the advantages of laser welding and arc welding. This laser hybrid welding can provide not only a fast welding speed but also improved seam quality, and is advantageous for preventing warping caused by heat, along with a stable process. Therefore, when the upper plate (110) and the lower plate (130) of the cooling block are welded together as a single body using this laser hybrid welding, watertightness can be ensured through defect-free welding, and furthermore, the phenomenon of fire or equipment failure caused by leakage of cooling water due to welding defects can be eliminated.

[0046] The welding quality inspection step (S160) is a process for determining the quality of a product by inspecting the welded parts of the upper plate (110) and the lower plate (130) of the cooling block using a welding inspection device (160) as shown in FIGS. 1 and 7. Through this process, only good quality products are supplied, and the finished product is the cooling block (100) of FIG. 8.

[0047] The structure of the cooling block (100) manufactured in this manner is described in more detail. The cooling block (100) includes a plate-shaped cooling block upper plate (110) and a cooling block lower plate (130). The cooling block upper plate (110) and the cooling block lower plate (130) are integrated through the aforementioned laser hybrid welding to form a single cooling block (100).

[0048] The cooling block top plate (110) forms the upper plate body of the cooling block (100) provided for cooling a vehicle battery pack.

[0049] And, the cooling block bottom plate (130) is a part that forms the lower plate body of the cooling block (100), and is integrated into one body with the cooling block top plate (110) through laser hybrid welding so that a cooling water channel (120) through which cooling water flows is formed between it and the cooling block top plate (110).

[0050] At this time, in order to form a cooling water channel (120), a channel upper plate (111) is formed on the upper plate (110) of the cooling block and a channel lower plate (131) is formed on the lower plate (130) of the cooling block, and a plurality of channel branching protrusions (132) are formed on the channel lower plate (131) to branch the direction of the cooling water channel (120) in several directions.

[0051] Even if there is only one space for the lower section of the Euro (131), multiple Euro branch protrusions (132) are formed in the lower section of the Euro (131), and cooling water flows through them, so the cooling efficiency can be increased. That is, the cooling efficiency can be increased because the heated cooling water can be recovered and cold cooling water can be supplied.

[0052] In this embodiment, the thickness of the upper plate (110) of the cooling block is made thicker than the thickness of the lower plate (130) of the cooling block.

[0053] Below, a series of processes for manufacturing a cooling block (100) is introduced.

[0054] First, as shown in FIGS. 1 and 2, a cooling block top plate (110), which is one side of a vehicle battery pack cooling block (100), is prepared.

[0055] Next, a cooling block bottom plate (130) to be welded and integrated with the cooling block top plate (110) as in FIGS. 1 and 3 is prepared. At this time, the cooling block top plate preparation step (S110) and the cooling block bottom plate preparation step (S120) can proceed independently in parallel. That is, either one can be performed first.

[0056] Next, as shown in FIGS. 1 and 4, the upper plate (110) of the cooling block and the lower plate (130) of the cooling block are placed in contact with each other so that a cooling water channel (120) through which cooling water flows is formed between the upper plate (110) of the cooling block and the lower plate (130).

[0057] Next, the welding location (140) of the upper cooling block plate (110) and the lower cooling block plate (130) arranged in contact surfaces as in FIGS. 1 and FIGS. 5 is selected. The welding location (140) may be directly marked, or only the location may be determined according to a program.

[0058] Next, welding is performed by a laser hybrid welding device (150) along selected welding locations (140) as in FIGS. 1 and 6, so that the upper plate (110) of the cooling block and the lower plate (130) of the cooling block are integrated into one body.

[0059] Then, as shown in FIGS. 1 and 7, the quality of the product is determined by inspecting the welded parts of the upper plate (110) and the lower plate (130) of the cooling block using a welded part inspection device (160). Through this process, only good quality products are supplied, and the finished product is the cooling block (100) of FIG. 8.

[0060] According to the present embodiment, which operates based on the structure described above, the upper and lower plates (110, 120) of the cooling block are welded together using a laser hybrid welding method different from the conventional one, thereby ensuring watertightness through defect-free welding. Furthermore, it is possible to eliminate the phenomenon of fire or equipment failure caused by leakage of cooling water due to welding defects.

[0061] FIGS. 9 and FIGS. 10 are process diagrams of key parts of a method for manufacturing a cooling block for a vehicle battery pack according to a second embodiment of the present invention.

[0062] Referring to these drawings, in the case of the present embodiment as well, the upper plate (110) of the cooling block and the lower plate (130) are welded together through laser hybrid welding by a laser hybrid welding device (150).

[0063] However, in the case of the present embodiment, a first laser irradiation groove (270) is formed on the top plate (110) of the cooling block before laser hybrid welding is performed. Then, the laser hybrid welding device (150) performs laser hybrid welding through the first laser irradiation groove (270). Then, not only can an accurate welding position be provided, but a welding bead can also be filled into the first laser irradiation groove (270), thereby providing a stronger welding quality.

[0064] Even when this embodiment is applied, the upper and lower plates (110, 120) of the cooling block can be welded together using a laser hybrid welding method different from the conventional one, thereby ensuring watertightness through defect-free welding, and furthermore, the phenomenon of fire or equipment failure caused by leakage of cooling water due to welding defects can be eliminated.

[0065] FIG. 11 is a process diagram of the main parts of a method for manufacturing a cooling block for a vehicle battery pack according to a third embodiment of the present invention.

[0066] Referring to this drawing, in this embodiment as well, the upper plate (110) of the cooling block and the lower plate (130) of the cooling block are welded together through laser hybrid welding by a laser hybrid welding device (150).

[0067] However, in the case of this embodiment, two first and second laser irradiation grooves (270, 370) are formed, and laser hybrid welding is performed on both of them. In this case, since double welding is performed on one welding area, it can be more effective in preventing leakage.

[0068] Even when this embodiment is applied, the upper and lower plates (110, 120) of the cooling block can be welded together using a laser hybrid welding method different from the conventional one, thereby ensuring watertightness through defect-free welding, and furthermore, the phenomenon of fire or equipment failure caused by leakage of cooling water due to welding defects can be eliminated. Explanation of the symbols

[0069] 100 : Cooling block 110 : Cooling block top plate 111: Euro top plate 120: Coolant flow path 130: Cooling block bottom plate 131: Flow path bottom plate section 132: Euro branch projection 140: Welding position 150: Laser hybrid welding device 160: Welding area inspection device

Claims

Claim 1 A method for manufacturing a cooling block for a vehicle battery pack, characterized by comprising: a cooling block upper plate preparation step for preparing a cooling block upper plate, which is one side of the cooling block for a vehicle battery pack; a cooling block lower plate preparation step for preparing a cooling block lower plate to be welded and integrated with the cooling block upper plate; a cooling block upper plate and a cooling block lower plate contact surface arrangement step for arranging the cooling block upper plate and the cooling block lower plate so that a cooling water flow path is formed between the cooling block upper plate and the cooling block lower plate, thereby forming a cooling water flow path between them; a welding position selection step for selecting a welding position of the cooling block upper plate and the cooling block lower plate arranged in contact surfaces; and a laser hybrid welding step for performing welding through a predetermined laser hybrid welding along the selected welding position so that the cooling block upper plate and the cooling block lower plate are integrated into one body. Claim 2 A method for manufacturing a cooling block for a vehicle battery pack according to claim 1, further comprising a welding quality inspection step for determining the quality of a product by inspecting the welded portions of the upper plate of the cooling block and the lower plate of the cooling block after performing the laser hybrid welding step, wherein the cooling block upper plate preparation step and the cooling block lower plate preparation step proceed independently in parallel. Claim 3 A cooling block for a vehicle battery pack, comprising: a cooling block top plate forming one side of the cooling block for a vehicle battery pack; and a cooling block bottom plate integrated into one body with the cooling block top plate through welding so as to form a cooling water channel through which cooling water flows between the cooling block top plate and the cooling block bottom plate, wherein the cooling block top plate and the cooling block bottom plate are welded together by laser hybrid welding to integrate into one body. Claim 4 A vehicle battery pack cooling block according to claim 3, wherein, for the formation of the cooling water flow path, a flow path upper plate portion is formed on the upper plate of the cooling block and a flow path lower plate portion is formed on the lower plate of the cooling block, and a plurality of flow path branching protrusions are formed on the lower plate of the cooling block to branch the direction of the cooling water flow path in multiple directions, and wherein the thickness of the upper plate of the cooling block is manufactured to be thicker than the thickness of the lower plate of the cooling block.

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