Battery pack structure with integrated die-casting molding of bottom protective plate and frame and die-casting process

Abstract

The invention discloses a battery pack structure with a bottom protective plate and a frame integrally formed by die casting and a die casting process, the structure comprises a lower box body frame, the bottom protective plate and a liquid cooling plate, the lower box body frame and the bottom protective plate are integrally formed, and the liquid cooling plate is directly embedded in the lower box body frame and the bottom protective plate; the split casting process specifically comprises the following steps: firstly, die-casting and forming the bottom guard plate; secondly, the formed bottom protection plate is used as a part of components of a die-casting die female die during secondary die-casting and is connected and formed with the integrated lower box body frame through pressurization, and die-casting of the lower box body frame is carried out; and finally forming a battery pack lower box body finished product. The integrated die-casting process is adopted, the lower box frame edge beam and the bottom protection plate are integrated, welding connection is not needed, the production efficiency is improved, and the tool cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of automobile battery packs, and more specifically to a battery pack structure and die-casting process in which a bottom guard plate and a frame are integrally die-cast. Background Art

[0002] The existing automotive battery pack manufacturing process mainly has the following technical problems: 1. Most existing new energy battery pack frames are made of profiles and sheet metal parts that are processed separately and then welded into an integrated structure. This process is costly and time-consuming, and cannot meet the current needs of new energy vehicles for fast upgrades and iterations and short R&D cycles. As shown in patent CN111883719A, its main structure includes an upper cover, a plurality of battery cell stacks, a frame and a bottom plate, wherein the plurality of battery cell stacks are placed in the frame, the upper cover covers the top of the frame, and a first sealing ring is provided between the upper cover and the top of the frame, and the bottom plate is installed at the bottom of the frame, such as Figure 1 However, its structure is complicated, the production process is complicated, and the weight is too heavy, which does not conform to the current trend of lightweight automobile development.

[0003] 2. In recent years, integrated die-casting technology has been widely used in various automotive parts and components, and is also used in the manufacture of battery packs. However, in the field of battery packs, due to the complex structure of the liquid cooling plate, it is impossible to form it in one go, which limits the application of integrated die-casting technology in the manufacture of battery packs. As shown in patent CN114069141A, its main structure includes the side beams and supporting transverse and longitudinal beams of the lower box frame, such as Figure 2 As shown, due to the special structural requirements of the liquid cooling plate, this design does not include a bottom guard plate, and additional mounting holes need to be processed on the die-cast battery pack.

[0004] 3. For complex structural parts, although integrated die-casting has the advantages of short cycle and fast molding, the one-time investment in die-casting machines and molds is relatively high, and some thin-walled areas are prone to defects such as insufficient pouring, resulting in the scrapping of parts. Summary of the invention

[0005] One object of the present invention is to provide a battery pack structure and die-casting process in which a bottom guard plate and a frame are integrally die-cast. The integrated die-casting process is used to integrate the side beams of the lower box frame and the bottom guard plate, without the need for welding connections, thereby improving production efficiency and reducing tooling costs.

[0006] In order to solve the above technical problems, the present invention provides a battery pack structure in which a bottom guard plate and a frame are integrally die-cast, comprising a lower box frame, a bottom guard plate and a liquid cooling plate, wherein the lower box frame and the bottom guard plate are integrally formed, and the liquid cooling plate is directly embedded in the lower box frame and the bottom guard plate.

[0007] Preferably, a plurality of riveted structures are provided on the lower box frame and the bottom guard plate.

[0008] The present invention also provides a die-casting process for a battery pack structure in which a bottom guard plate and a frame are integrally die-cast, and a separate casting process is adopted, that is, the bottom guard plate and the lower box frame are die-cast separately.

[0009] Preferably, the split casting process is as follows: first, die-cast a bottom guard plate; secondly, use the formed bottom guard plate as a partial component of the die-casting mold during the secondary die-casting, connect it with the integrated lower box frame through the solidification shrinkage of the molten metal and the riveting structure, and die-cast the lower box frame; finally, form a finished product of the battery pack lower box.

[0010] Preferably, when the lower box frame is die-cast, the liquid cooling plate is embedded in the groove of the bottom guard plate and then die-casting is performed.

[0011] Preferably, when die-casting the bottom guard plate, a bottom guard plate punch and a bottom guard plate concave die are used for die-casting.

[0012] Preferably, when the lower box frame is die-cast, the lower box frame die and the bottom guard plate die share one die, the bottom guard plate is embedded in the bottom guard plate die, and the liquid cooling plate is embedded in the groove of the bottom guard plate.

[0013] Preferably, when the lower box frame is die-cast, the four side surfaces, the top surface and the interior corresponding to the lower box frame are die-cast respectively by setting a lower box frame convex mold.

[0014] The present invention has at least the following beneficial effects: 1. The present invention adopts an integrated die-casting process to integrate the side beams of the lower box frame and the bottom guard plate, without the need for welding connection, thereby improving production efficiency and reducing tooling costs.

[0015] 2. The present invention adopts a split casting molding process, first molding the bottom guard plate, and then molding the lower box frame, avoiding casting defects caused by a large difference in wall thickness between the bottom guard plate and the lower box frame beam, while reducing the requirements for the tonnage of the die-casting machine. Through secondary die-casting, the bottom guard plate is embedded in the concave mold of the lower box frame, and the connection with the lower box frame can be completed without welding, which simplifies the process and saves mold costs.

[0016] 3. The liquid cooling plate of the present invention is embedded in the groove of the bottom guard plate, without the need for FDS or stir friction welding in the traditional process, and the connection with the lower box frame is completed at one time during the secondary die casting, without the need for sealing rings and fixtures. Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1It is a structural schematic diagram of the prior art in the background technology; Figure 2 It is a structural schematic diagram of the prior art in the background technology; Figure 3 This is a schematic diagram of the lower box structure of the battery pack of the present invention; Figure 4 This is a schematic diagram of the die-casting mold structure of the bottom guard plate of the present invention; Figure 5 This is a schematic diagram of the structure of the die-casting mold for the lower box frame of the present invention; Figure 6 It is a die-casting process flow chart of the present invention. DETAILED DESCRIPTION

[0018] In order to better understand the purpose, structure and function of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings so that those skilled in the art can implement it according to the description.

[0019] It should be noted that the experimental methods described in the following embodiments are conventional methods unless otherwise specified, and the reagents and materials are commercially available unless otherwise specified; in the description of the present invention, the terms "lateral", "longitudinal", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0020] like Figure 3 As shown, the present invention provides a battery pack structure in which a bottom guard plate and a frame are integrally die-cast, comprising a lower box frame 1, a bottom guard plate 2 and a liquid cooling plate 3. The lower box frame 1 and the bottom guard plate 2 are integrally formed, and the liquid cooling plate 3 is directly embedded in the lower box frame 1 and the bottom guard plate 2. The lower box frame 1 and the bottom guard plate 2 are provided with a plurality of riveted structures.

[0021] The battery pack lower box integrates the battery pack lower box frame and bottom guard plate structure, without welding. After one-time molding, it only needs CNC to process 46 riveted structures before it can be put into use. The battery pack liquid cooling plate is embedded in the battery pack lower box frame and bottom guard plate. The structure is simple and does not require FDS connection and stir friction welding.

[0022] The present invention also provides a die-casting process for a battery pack structure in which the bottom guard plate and the frame are integrally die-cast, and the die-casting process is adopted, that is, the bottom guard plate and the lower box frame are die-cast separately. The specific die-casting process is as follows: Figure 6As shown, first, the bottom guard plate is die-cast; secondly, the formed bottom guard plate is used as a partial component of the die-casting mold during the secondary die-casting, and is connected with the integrated lower box frame through the solidification shrinkage of the molten metal and the riveting structure, and the lower box frame is die-cast; finally, the finished battery pack lower box is formed.

[0023] The battery pack adopts the split casting process, the bottom guard plate is initially die-casted, and then the formed bottom guard plate is used as part of the die-casting die concave mold during the secondary die-casting, and is connected to the integrated lower box frame by pressurization. The battery pack die-casting mold has a simple structure. The process design of separate die-casting of the bottom guard plate and the lower box frame avoids defects such as insufficient pouring due to uneven wall thickness, reduces the requirements for the tonnage of the die-casting machine, and reduces the cost of mold design.

[0024] In another technical solution, when the lower box frame is die-cast, the liquid cooling plate is embedded in the groove of the bottom guard plate and then die-cast. The liquid cooling plate is a precision structure that requires extrusion and CNC processing, and then is connected by die-casting to fix the liquid cooling plate between the lower box frame and the bottom guard plate.

[0025] In another technical solution, Figure 4 As shown, when the bottom guard plate 2 is die-cast, a bottom guard plate punch 7 and a bottom guard plate die 4 are used for die-casting.

[0026] In another technical solution, Figure 5 As shown, when the lower box frame 1 is die-cast, the lower box frame die 5 and the bottom guard plate die 4 share a die, that is, the lower box frame die 5 and the bottom guard plate die 4 are a component, the bottom guard plate 2 is embedded in the bottom guard plate die 4, and the liquid cooling plate 3 is embedded in the bottom guard plate groove. When the lower box frame 1 is die-cast, the four corresponding side surfaces, the top surface and the interior of the lower box frame 1 are die-cast by setting the lower box frame convex mold 6 respectively.

[0027] It is understood that the present invention is described by some embodiments, and those skilled in the art are aware that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation mode, and they can be fully applied to various fields suitable for the present invention. For those familiar with the art, other modifications can be easily implemented, so without departing from the general concept defined by the claims and the equivalent scope, the present invention is not limited to the specific details and the illustrations shown and described here.

Claims

1. The battery pack structure with integrated die-casting of the bottom guard plate and the frame is characterized by: It comprises a lower box frame, a bottom guard plate and a liquid cooling plate. The lower box frame and the bottom guard plate are integrally formed, and the liquid cooling plate is directly embedded in the lower box frame and the bottom guard plate.

2. The battery pack structure with the bottom guard plate and the frame integrally die-cast as claimed in claim 1, characterized in that: The lower box frame and the bottom guard plate are provided with a plurality of riveted structures.

3. The die-casting process of the battery pack structure with the bottom guard plate and the frame integrally die-casted is characterized in that: The split casting process is adopted, that is, the bottom guard plate and the lower box frame are die-cast separately.

4. The die-casting process for the battery pack structure in which the bottom guard plate and the frame are integrally die-cast as claimed in claim 3, characterized in that: The specific process of the split casting method is as follows: first, the bottom guard plate is die-cast; secondly, the formed bottom guard plate is used as a partial component of the die-casting mold concave mold during the secondary die-casting, and the lower box frame is connected and formed through the solidification shrinkage of the molten metal, and the lower box frame is die-cast; finally, the finished battery pack lower box is formed.

5. The die-casting process for the battery pack structure in which the bottom guard plate and the frame are integrally die-cast as claimed in claim 4, characterized in that: When the lower box frame is die-cast, the liquid cooling plate is embedded in the groove of the bottom guard plate and then die-casting is performed.

6. The die-casting process for the battery pack structure in which the bottom guard plate and the frame are integrally die-cast as claimed in claim 4, characterized in that: When the bottom guard plate is die-cast, a bottom guard plate punch and a bottom guard plate concave die are used for die-casting.

7. The die-casting process for the battery pack structure in which the bottom guard plate and the frame are integrally die-cast as claimed in claim 4, characterized in that: When the lower box frame is die-cast, the lower box frame die and the bottom guard plate die share one die, the bottom guard plate is embedded in the bottom guard plate die, and the liquid cooling plate is embedded in the groove of the bottom guard plate.

8. The die-casting process for the battery pack structure in which the bottom guard plate and the frame are integrally die-cast as claimed in claim 7, characterized in that: When the lower box frame is die-cast, four side surfaces, the top surface and the interior corresponding to the lower box frame are die-cast respectively by setting a lower box frame convex mold.

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