Connecting bracket for upper layer and lower layer of battery pack box body of electric truck

Abstract

An upper and lower layer connecting support for a battery pack box body of an electric truck comprises an upper connecting plate, a radial plate and a lower connecting seat, the radial plate comprises a flat rectangular shell located in the middle and connecting parts fixedly connected to the two ends of the flat rectangular shell. Each connecting part is of a hollow cone-like metal structure, one connecting part is connected with the upper connecting plate in a welded mode, and the other connecting part is connected with the lower connecting base in a welded mode; compared with casting, the upper connecting plate formed by stamping a metal plate and the lower connecting seat formed by forging the metal plate have the advantages that the production efficiency is greatly improved, and the labor cost is obviously reduced; under the same weight, the left-right bending resistance strength and rigidity of the radial plate are obviously higher than those of a cast radial plate in the prior art, if the left-right bending resistance strength and rigidity of the radial plate are kept unchanged, the weight of the radial plate can be obviously reduced, the material cost can be reduced, the upper connecting plate, the lower connecting seat and the radial plate can be easily connected through low-cost automatic welding, and the service life of the radial plate is prolonged. And the production efficiency is further improved.

Description

Technical Field

[0001] This utility model relates to a battery pack housing support for electric trucks, and in particular to a connecting support for the upper and lower layers of a battery pack housing for electric trucks. Background Technology

[0002] As the driving range of electric trucks increases, the battery pack housings are becoming larger. The battery packs contain two battery trays, upper and lower, connected by several supports that bear the weight of the upper tray and batteries. The existing supports are solid components cast from QT450 steel, with a flat rectangular shape, arranged in descending order of length (longest side), width (widest side), and shortest side. The long side of the cuboid runs vertically, while the wide side runs along the truck's front-to-back direction within the housing. Functionally, the supports are divided into three parts: an upper connecting plate, a lower connecting seat, and the largest component, the spokes. Each part is symmetrical about the neutral layer of the spokes in the front-to-back direction. To allow the spokes to avoid obstacles on their sides, the middle section of the spokes is significantly thinner and longer than the ends. The lower connecting body of the supports is fixed to the base, and the upper connecting body is flexibly connected via a tray crossbeam. When the vehicle travels on a relatively flat road, the spokes primarily bear the vertical dynamic load. However, when the vehicle travels on a bumpy road and sways from side to side, the upper part of the spokes also bears the lateral dynamic load. This lateral dynamic load has a greater impact on the damage and deformation of the spokes than the vertical dynamic load, potentially causing the spokes to break from the lower middle section, which is the critical section. Several short ribs symmetrical about the neutral layer are set on both sides of the spokes. When the critical section is cut horizontally, the material of the section is mainly distributed near the neutral axis, which is coplanar with the neutral layer, with a small portion distributed further away from the neutral axis as short ribs. This cross-sectional shape is not conducive to improving the strength and stiffness of the support against lateral bending, failing to make full use of materials and increasing material costs. To reduce material consumption, the support is designed with certain complex shapes of weight-reducing holes or defects, increasing casting difficulty, reducing yield, and increasing costs. The casting process dictates that the thickness of the support cannot be too thin, resulting in a heavy support, which is detrimental to the lightweighting of electric trucks. Utility Model Content

[0003] The purpose of this utility model is to provide a connecting bracket for the upper and lower layers of an electric truck battery pack housing, which replaces the cast bracket with a plate and tube welded bracket, thereby reducing the weight of the bracket, improving production efficiency, and reducing the cost of the bracket.

[0004] The technical solution of this utility model is as follows:

[0005] An upper and lower connecting bracket for an electric truck battery pack housing includes an upper connecting plate, a spoke plate, and a lower connecting seat;

[0006] The spokes include a flat rectangular shell made of metal located in the middle and connecting parts fixedly connected to both ends of the flat rectangular shell;

[0007] The connecting part is a hollow cone-shaped structure, with one connecting part welded to the upper connecting plate and the other connecting part welded to the lower connecting seat.

[0008] Furthermore, the connecting part and the flat rectangular shell are an integral structure.

[0009] Furthermore, the width of the connecting portion is the same as the width of the flat rectangular shell.

[0010] Furthermore, the thickness of the connecting portion is greater than the thickness of the flat rectangular shell.

[0011] Furthermore, the upper connecting plate has a threaded hole, and the lower connecting seat has a mounting hole.

[0012] The present invention, by adopting the above technical solution, can achieve the following beneficial effects:

[0013] Compared to casting, the production efficiency of the upper connecting plate, which is formed by stamping metal sheets, and the lower connecting seat, which is formed by forging, is greatly improved and the labor cost is significantly reduced. The spokes are formed by hydraulic expansion of thin-walled metal tubes. Under the same weight, their resistance to lateral bending and stiffness are significantly higher than those of cast spokes in the existing technology. If the resistance to lateral bending and stiffness of the spokes are kept unchanged, the weight of the spokes will be significantly reduced, reducing material costs. Moreover, the upper connecting plate, the lower connecting seat and the spokes can be easily connected by low-cost automated welding, further improving production efficiency. Attached Figure Description

[0014] Figure 1 Axonometric drawing of the external shape of the prior art;

[0015] Figure 2 This is an isometric drawing of the external shape of this utility model;

[0016] Figure 3 This is a longitudinal sectional view of the support frame;

[0017] Figure 4 This is a cross-sectional view of the middle part of the spokes.

[0018] In the diagram, 1-upper connecting plate, 2-spoke plate, 3-lower connecting seat, 4-circumferential weld, 5-threaded hole, 6-mounting hole. Detailed Implementation

[0019] like Figure 1-4 As shown, an upper and lower connecting bracket for an electric truck battery pack housing includes an upper connecting plate 1, a spoke plate 2, and a lower connecting seat 3.

[0020] The spoke 2 includes a flat rectangular shell made of metal located in the middle and connecting parts fixedly connected to both ends of the flat rectangular shell; one connecting part is welded to the upper connecting plate 1 and the other connecting part is welded to the lower connecting seat 3, and an annular weld 4 is formed at the connection.

[0021] Specifically, the connecting part is a hollow, cone-shaped structure with open ends. The larger opening is used to connect with the upper connecting plate 1 or the lower connecting seat 3, and the smaller opening is used to connect with the flat rectangular shell. In this embodiment, the thickness of the connecting part is greater than the thickness of the flat rectangular shell, the width of the connecting part is the same as the width of the flat rectangular shell, and the connecting part and the flat rectangular shell are an integral structure. The whole is made of metal round tubes that have been cut and flattened or directly made from metal flat tubes into blank tubes. The blank tube is placed in a hydraulic expansion mold, and two moving molds are used to seal both ends of the blank tube. One of the moving molds is connected to the hydraulic system. The hydraulic press moves down to close the mold, and high-pressure liquid is injected into the blank tube through one of the moving molds. The blank tube deforms, and its outer wall fits into the inner cavity of the expansion mold to form a spoke.

[0022] In order to facilitate the connection of the upper and lower battery trays, a threaded hole 5 is provided on the upper connecting plate 1, and a mounting hole 6 is provided on the lower connecting seat 3.

[0023] Figure 1 An axonometric view of the external shape of a prior art cast support is shown, wherein the moment of inertia of the critical section of the cast spoke 2 resisting lateral load bending is 0.495 cm. 4 The section modulus is 0.899 cm. 3 The yield strength of the material is 3038 kg / cm². 2 The maximum bending moment it can withstand is 2731 kg·cm; under the same external dimensions, this utility model adopts a yield strength of 2989 kg / cm. 2 Flat steel pipes with a wall thickness of 1.5mm are hydraulically expanded to form spokes 2, the moment of inertia of which resists lateral bending under lateral loads at its critical section is 0.986cm. 4 The section modulus is 1.799 cm. 3 The maximum bending moment it can withstand is 5377 kg·cm. Table 1 below shows a more intuitive comparison of the data between the existing connecting bracket and the connecting bracket of this utility model:

[0024]

[0025] Table 1

[0026] As shown in Table 1, the present invention improves the bending stiffness by 99% and the bending strength by 97% compared with the prior art.

[0027] Based on truck design requirements, finite element analysis was performed on the existing technology and the bracket of this utility model under a dynamic load of 14292N in the vertical direction. The maximum stress inside the bracket of this utility model is less than that of the existing technology. The bracket of the existing technology weighs 2.17kg, while the bracket of this utility model weighs 1.48kg, a reduction of 0.69kg, or 31.8%, which is a very significant weight reduction effect.

[0028] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any equivalent substitutions and modifications made by those skilled in the art without departing from the guidance of the present utility model shall be deemed to fall within the protection scope of the present utility model.

Claims

1. A connecting bracket for the upper and lower layers of an electric truck battery pack housing, characterized in that: It includes an upper connecting plate (1), a spoke plate (2), and a lower connecting seat (3); The spoke (2) includes a flat rectangular shell made of metal located in the middle and connecting parts fixedly connected to both ends of the flat rectangular shell; The connecting part is a hollow cone-shaped structure, one of which is welded to the upper connecting plate (1), and the other is welded to the lower connecting seat (3).

2. The upper and lower layer connecting bracket of the electric truck battery pack housing according to claim 1, characterized in that: The connecting part and the flat rectangular shell are an integral structure.

3. The upper and lower layer connecting bracket for the electric truck battery pack housing according to claim 1 or 2, characterized in that: The width of the connecting part is the same as the width of the flat rectangular shell.

4. The upper and lower layer connecting bracket of the electric truck battery pack housing according to claim 3, characterized in that: The thickness of the connecting part is greater than the thickness of the flat rectangular shell.

5. The upper and lower layer connecting bracket of the electric truck battery pack housing according to claim 1, characterized in that: The upper connecting plate (1) has a threaded hole (5), and the lower connecting seat (3) has a mounting hole (6).

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